Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung,...
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Transcript of Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung,...
![Page 1: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/1.jpg)
Lipid membranes between nano and
micro:
Lipid membranes between nano and
micro:
Markus DesernoMax-Planck-Institut für Polymerforschung, Mainz
Cells and Materials, Workshop I: Membrane Protein Science and Engineering
http://www.mpip-mainz.mpg.de/~desernohttp://www.mpip-mainz.mpg.de/~deserno
IPAM, Los Angeles, California, USA
[email protected]@mpip-mainz.mpg.de
A solvent-free coarse-grained simulation model
A solvent-free coarse-grained simulation model
(and what we can learn from it)(and what we can learn from it)
![Page 2: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/2.jpg)
Motivation
![Page 3: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/3.jpg)
Motivation
Cells !
![Page 4: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/4.jpg)
Motivation
Cells & Materials !
![Page 5: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/5.jpg)
Motivation
Cells & Materials?
![Page 6: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/6.jpg)
Some simple scaling
![Page 7: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/7.jpg)
Some simple scaling
Thickness: 5 nm
![Page 8: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/8.jpg)
Some simple scaling
Thickness: 5 nm
Lipids ~ dense hydrocarbons ~ typical length scale: 5 nm ~ between rubber and plastic ~ Young modulus: Pa107
![Page 9: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/9.jpg)
Some simple scaling
Pa107Y
3121 hY
nm5h
![Page 10: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/10.jpg)
Some simple scaling
Pa107Y
3121 hY
Young’s modulusbending modulus
membrane
thickness
nm5h
![Page 11: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/11.jpg)
Some simple scaling
Pa107Y
3121 hY
Young’s modulusbending modulus
membrane
thickness
nm5h
TkB25
![Page 12: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/12.jpg)
Some simple scaling
Pa107Y
3121 hY
Young’s modulusbending modulus
membrane
thickness
nm5h
TkB25 That’s about right!
![Page 13: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/13.jpg)
ImplicationsBending modulus of phospholipid bilayers:
a few tens of kT
Why’s that such an interesting value?
![Page 14: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/14.jpg)
ImplicationsBending modulus of phospholipid bilayers:
a few tens of kT
Why’s that such an interesting value?• bigger than thermal energy
Bilayer doesn’t fluctuate into pieces!
![Page 15: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/15.jpg)
ImplicationsBending modulus of phospholipid bilayers:
a few tens of kT
Why’s that such an interesting value?• bigger than thermal energy
Bilayer doesn’t fluctuate into pieces!
• not much bigger than thermal energy
Nano-sources of energy can deform it!
![Page 16: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/16.jpg)
ImplicationsBending modulus of phospholipid bilayers:
a few tens of kT
Why’s that such an interesting value?
Ideal material for nano-technology !
• bigger than thermal energy
Bilayer doesn’t fluctuate into pieces!
• not much bigger than thermal energy
Nano-sources of energy can deform it!
![Page 17: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/17.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
![Page 18: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/18.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
![Page 19: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/19.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
Just turn the argument around:
![Page 20: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/20.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
Just turn the argument around:
3121 hY
![Page 21: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/21.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
Just turn the argument around:
3121 hY
TkB25
![Page 22: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/22.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
Just turn the argument around:
3121 hY
TkB25 Pa1010
(metal)
![Page 23: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/23.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
Just turn the argument around:
3121 hY
TkB25 Pa1010
nm5.0h
(metal)
![Page 24: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/24.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
Just turn the argument around:
3121 hY
TkB25 Pa1010
nm5.0h
falls apart !(metal)
![Page 25: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/25.jpg)
But front-cover “NanoTech” seems to be shiny metal stuff!
Just turn the argument around:
3121 hY
TkB25 Pa1010
nm5.0h
falls apart !
Nanotechnology
invariably means
soft matter!
Nanotechnology
invariably means
soft matter!
(metal)
![Page 26: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/26.jpg)
Nature has found out first!
Membranes everywhere !
![Page 27: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/27.jpg)
A closer look…Lipid bilayers show interesting physics on many different length scales.
Self-assembly
Protein-embeddingFluidity
Pressure-profilesBending-deformations
J. G
ould
and W
. K
eeto
n,
Bio
logic
al Sci
ence
,6
th e
d.
(W.W
. N
ort
on,
New
York
, 1
99
6)
![Page 28: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/28.jpg)
A closer look…Lipid bilayers show interesting physics on many different length scales.
J. G
ould
and W
. K
eeto
n,
Bio
logic
al Sci
ence
,6
th e
d.
(W.W
. N
ort
on,
New
York
, 1
99
6)
When studying this system, one’s approach should be tuned towards the length scale one intends to probe.
![Page 29: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/29.jpg)
Lipid bilayers show interesting physics on many different length scales.
J. G
ould
and W
. K
eeto
n,
Bio
logic
al Sci
ence
,6
th e
d.
(W.W
. N
ort
on,
New
York
, 1
99
6)
When studying this system, one’s approach should be tuned towards the length scale one intends to probe.
any
A closer look…
![Page 30: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/30.jpg)
Lipid bilayers show interesting physics on many different length scales.
J. G
ould
and W
. K
eeto
n,
Bio
logic
al Sci
ence
,6
th e
d.
(W.W
. N
ort
on,
New
York
, 1
99
6)
When studying this system, one’s approach should be tuned towards the length scale one intends to probe.
Theory
any
A closer look…
![Page 31: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/31.jpg)
Lipid bilayers show interesting physics on many different length scales.
Simulation
J. G
ould
and W
. K
eeto
n,
Bio
logic
al Sci
ence
,6
th e
d.
(W.W
. N
ort
on,
New
York
, 1
99
6)
When studying this system, one’s approach should be tuned towards the length scale one intends to probe.
Theory
any
A closer look…
![Page 32: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/32.jpg)
Lipid bilayers show interesting physics on many different length scales.
Simulation
J. G
ould
and W
. K
eeto
n,
Bio
logic
al Sci
ence
,6
th e
d.
(W.W
. N
ort
on,
New
York
, 1
99
6)
Experiment
When studying this system, one’s approach should be tuned towards the length scale one intends to probe.
Theory
any
A closer look…
![Page 33: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/33.jpg)
Lipid bilayers show interesting physics on many different length scales.
Simulation
J. G
ould
and W
. K
eeto
n,
Bio
logic
al Sci
ence
,6
th e
d.
(W.W
. N
ort
on,
New
York
, 1
99
6)
Experiment
When studying this system, one’s approach should be tuned towards the length scale one intends to probe.
Theory
any
A closer look…
![Page 34: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/34.jpg)
Simulation of lipid membranes
i n c r e a s i n g l y c o a r s e g r a i n e d
much detail little detail
atomistic models triangulated surfacesbead-spring models
“standard”Lennard-Jones
DPD solvent free
increasing numerical efficiencymatter of debate…
Marrink; Klein, Sansom; Scott; Voth; …
Gompper&Kroll,…
Goetz&Lipowsky;Stevens; …
Groot&Rabone;Shillcock&Lipowsky;Laradji&Kumar, …
Drouffe&Maggs&Leibler;Noguchi&Takasu; Farago;
Brannigan&Brown
![Page 35: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/35.jpg)
Simulation of lipid membranes
i n c r e a s i n g l y c o a r s e g r a i n e d
much detail little detail
atomistic models triangulated surfacesbead-spring models
“standard”Lennard-Jones
DPD solvent free
increasing numerical efficiencymatter of debate…
Marrink; Klein, Sansom; Scott; Voth; …
Gompper&Kroll,…
Goetz&Lipowsky;Stevens; …
Groot&Rabone;Shillcock&Lipowsky;Laradji&Kumar, …
Drouffe&Maggs&Leibler;Noguchi&Takasu; Farago;
Brannigan&Brown
![Page 36: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/36.jpg)
Why is “solvent free” good?
![Page 37: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/37.jpg)
Why is “solvent free” good?
membrane surface
![Page 38: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/38.jpg)
Why is “solvent free” good?
membrane surface
solvent bulk
![Page 39: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/39.jpg)
Why is “solvent free” good?
membrane surface
solvent bulk
![Page 40: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/40.jpg)
Why is “solvent free” good?
membrane surface
solvent bulk
Studying membranes may well become the study of a finite size
effect!
Studying membranes may well become the study of a finite size
effect!
![Page 41: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/41.jpg)
Illustrative examplemembrane surface
solvent bulk
M. Laradji, P. B. Sunil Kumar,Phys. Rev. Lett. 93, 198105 (2004)
16000 (DPD) lipids times 4 beads per lipid 64000 degrees of freedom for lipids
But in total: 1536000 particles in box
96% of simulation time spent with solvent!
![Page 42: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/42.jpg)
“No solvent” is difficult. Why?Implicit solvent models are very commonand incredibly useful in polymer physics.
Why are they not so common in the membrane field?
![Page 43: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/43.jpg)
“No solvent” is difficult. Why?Implicit solvent models are very commonand incredibly useful in polymer physics.
Why are they not so common in the membrane field?
Polymers don’t first have to self-assemble
![Page 44: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/44.jpg)
“No solvent” is difficult. Why?Implicit solvent models are very commonand incredibly useful in polymer physics.
Why are they not so common in the membrane field?
Polymers don’t first have to self-assemble
One needs to introduce additional cohesive energy for the lipid tails!
![Page 45: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/45.jpg)
kBT, not eV!
“No solvent” is difficult. Why?Implicit solvent models are very commonand incredibly useful in polymer physics.
Why are they not so common in the membrane field?
Polymers don’t first have to self-assemble
One needs to introduce additional cohesive energy for the lipid tails!
![Page 46: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/46.jpg)
kBT, not eV!
“No solvent” is difficult. Why?Implicit solvent models are very commonand incredibly useful in polymer physics.
Why are they not so common in the membrane field?
Fluidity has proven to be the main challenge
Polymers don’t first have to self-assemble
One needs to introduce additional cohesive energy for the lipid tails!
![Page 47: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/47.jpg)
DifficultiesPolymers don’t first have to self-assemble
Fluidity has proven to be the main challenge
“gas” phase
solid bilayer
weak attraction
strong attraction
Empirical observation:
![Page 48: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/48.jpg)
no fluid phase
inbetween!
no fluid phase
inbetween!
DifficultiesPolymers don’t first have to self-assemble
Fluidity has proven to be the main challenge
“gas” phase
solid bilayer
weak attraction
strong attraction
Empirical observation:
![Page 49: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/49.jpg)
no fluid phase
inbetween!
no fluid phase
inbetween!
DifficultiesPolymers don’t first have to self-assemble
Fluidity has proven to be the main challenge
“gas” phase
solid bilayer
weak attraction
strong attraction
Empirical observation:
This observation is incorrect.But we’ll later see where it came from!
![Page 50: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/50.jpg)
Previous and current solutions• J.-M. Drouffe, A. C. Maggs, and S. Leibler, Science 254, 1353 (1991)• H. Noguchi and M. Takasu, Phys. Rev. E 64, 041913 (2001)• Z.J. Wang and D. Frenkel, J. Chem. Phys. 122, 234711 (2005)• H. Noguchi and G. Gompper, Phys. Rev. E 72, 021903 (2006)
• O. Farago, J. Chem. Phys. 119, 396 (2003)
• G. Brannigan and F.L.H. Brown, J. Chem. Phys. 120, 1059 (2004)
• G. Ayton and G.A. Voth, Biophys. J. 83, 3357 (2002)
• I.R. Cooke, K. Kremer, M. Deserno, Phys. Rev. E 72, 011506 (2005)• G. Brannigan, P.F. Philips, and F.L.H. Brown, Phys. Rev. E 72, 011915, (2005)
![Page 51: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/51.jpg)
Previous and current solutions• J.-M. Drouffe, A. C. Maggs, and S. Leibler, Science 254, 1353 (1991)• H. Noguchi and M. Takasu, Phys. Rev. E 64, 041913 (2001)• Z.J. Wang and D. Frenkel, J. Chem. Phys. 122, 234711 (2005)• H. Noguchi and G. Gompper, Phys. Rev. E 72, 021903 (2006)
• O. Farago, J. Chem. Phys. 119, 396 (2003)
• G. Brannigan and F.L.H. Brown, J. Chem. Phys. 120, 1059 (2004)
• G. Ayton and G.A. Voth, Biophys. J. 83, 3357 (2002)
• I.R. Cooke, K. Kremer, M. Deserno, Phys. Rev. E 72, 011506 (2005)• G. Brannigan, P.F. Philips, and F.L.H. Brown, Phys. Rev. E 72, 011915, (2005)
Multibody interactions
Tethered membrane
Highly tuned Lennard-Jones
Angle-dependent potentials
Pair-potentials
![Page 52: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/52.jpg)
Our own model
Three bead lipid
I.R. Cooke, K. Kremer, M. Deserno,Phys. Rev. E 72, 011506 (2005)
![Page 53: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/53.jpg)
Our own model
Three bead lipid
Only three beads
?
I.R. Cooke, K. Kremer, M. Deserno,Phys. Rev. E 72, 011506 (2005)
![Page 54: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/54.jpg)
Our own model
Three bead lipid
Only three beads
?
I.R. Cooke, K. Kremer, M. Deserno,Phys. Rev. E 72, 011506 (2005)
Look at the aspect ratio for real lipids:
3nm0.7
nm5.2
moleculeper area
icknessbilayer th2
21
![Page 55: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/55.jpg)
Our own model
Three bead lipidhead
tail}
[I. R. Cooke, K. Kremer, M. Deserno, 2005)]
Linked by two bonds
Stiffened by (effective) bending potential
![Page 56: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/56.jpg)
Our own model
Three bead lipid
Stiffened by (effective) bending potential
Tail attraction via some generic potential with tunable range
Linked by two bonds
[I. R. Cooke, K. Kremer, M. Deserno, 2005)]
![Page 57: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/57.jpg)
Our own model
Three bead lipid
Stiffened by (effective) bending potential
Tail attraction via some generic potential with tunable range
Linked by two bonds
2 parameters!
[I. R. Cooke, K. Kremer, M. Deserno, 2005)]
![Page 58: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/58.jpg)
Simulation
• Molecular Dynamics• Langevin thermostat• constant volume/area or constant pressure/tension• Simulation software: ESPResSo
http://www.espresso.mpg.dehttp://www.espresso.mpg.de
c-core controlled via tcl scripts
or: pairwise(DPD
thermostat)
![Page 59: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/59.jpg)
Self-assembly
![Page 60: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/60.jpg)
Example of a self-assembly run
4000 lipids, 100LJ between frames (1000), 10kBT
![Page 61: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/61.jpg)
Tensionless phase diagram
gel-phase(s)gel-phase(s)
fluid phasefluid phase
unstableunstable
![Page 62: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/62.jpg)
The tragedy of Lennard-JonesLJ potential with artificially “stretched” minimum
gel-phase(s)gel-phase(s)
fluid phasefluid phase
unstableunstable
![Page 63: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/63.jpg)
Bending modulusFluctuation spectrum from continuum Helfrich theory:
![Page 64: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/64.jpg)
Bending modulusFluctuation spectrum from continuum Helfrich theory:
extrinsiccurvature
surfacetension
“Linearized Monge”
![Page 65: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/65.jpg)
Bending modulusFluctuation spectrum from continuum Helfrich theory:
Fourier expansion plus equipartition theorem:
extrinsiccurvature
surfacetension
“Linearized Monge”
![Page 66: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/66.jpg)
Bending modulusFluctuation spectrum from continuum Helfrich theory:
Fourier expansion plus equipartition theorem:
zero tension
extrinsiccurvature
surfacetension
“Linearized Monge”
![Page 67: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/67.jpg)
Bending modulusFluctuation spectrum from continuum Helfrich theory:
Fourier expansion plus equipartition theorem:
zero tension
extrinsiccurvature
surfacetension
“Linearized Monge”
![Page 68: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/68.jpg)
Bending modulus
determinebendingmodulus
Fluctuation spectrum from continuum Helfrich theory:
Fourier expansion plus equipartition theorem:
zero tension
extrinsiccurvature
surfacetension
“Linearized Monge”
![Page 69: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/69.jpg)
Bending modulus
=0
tunable within experimentally relevant range!
![Page 70: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/70.jpg)
Bending modulus
Worries: We’re only probing very weak bending!
![Page 71: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/71.jpg)
Bending modulus
Worries: We’re only probing very weak bending!
![Page 72: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/72.jpg)
Bending modulus
Worries: We’re only probing very weak bending!
![Page 73: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/73.jpg)
Bending modulus
Worries: We’re only probing very weak bending!
![Page 74: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/74.jpg)
Bending modulus
Worries: We’re only probing very weak bending!
This is much weaker bending than what we’d typically like to do in a
simulation!
![Page 75: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/75.jpg)
Bending modulusAlternative: measure response to bending deformation!
![Page 76: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/76.jpg)
Bending modulusAlternative: measure response to bending deformation!
First imple-mentation:
W.K. den Otter and W.J. Briels,J. Chem. Phys. 118, 4712 (2003)
(Impose undulation mode,measure constraining force bending modulus)
![Page 77: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/77.jpg)
Bending modulusAlternative: measure response to bending deformation!
First imple-mentation:
W.K. den Otter and W.J. Briels,J. Chem. Phys. 118, 4712 (2003)
Easier method: Stretch a membrane tether!
(Impose undulation mode,measure constraining force bending modulus)
[V. Harmandaris and M. Deserno, in preparation]
![Page 78: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/78.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Energy:RR
LL
![Page 79: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/79.jpg)
Bending modulus
Energy:
Force:
RR
LL
![Page 80: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/80.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Energy:
Force:
Bending modulus:
RR
LL
![Page 81: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/81.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Energy:
Force:
Bending modulus:
What about fluctuations?
RR
LL
![Page 82: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/82.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Energy:
Force:
Bending modulus:
What about fluctuations?
goes up
RR
LL
![Page 83: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/83.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Energy:
Force:
Bending modulus:
What about fluctuations?
goes up goes down
RR
LL
![Page 84: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/84.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Energy:
Force:
Bending modulus:
What about fluctuations?
goes up goes down
(plane waveapproximation)
RR
LL
![Page 85: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/85.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Simulation:
![Page 86: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/86.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Simulation:
Result fromfluctuations
![Page 87: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/87.jpg)
Bending modulus
[V. Harmandaris and M. Deserno, in preparation]
Simulation:
Result fromfluctuations
Within our resolution no “stiffening” of the membrane at
large curvatures is observed!
Within our resolution no “stiffening” of the membrane at
large curvatures is observed!
![Page 88: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/88.jpg)
Domain induced budding
mixed-lipidmembrane
demixing budding
time
![Page 89: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/89.jpg)
Domain induced budding
mixed-lipidmembrane
demixing budding
time
T. Baumgart, S.T. Hess, W.W. Webb, Nature 425, 821 (2003)
5m
5m
sphingomyelin & cholesterol, Lo
DOPC & cholesterol, Ld
![Page 90: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/90.jpg)
Domain induced budding
mixed-lipidmembrane
demixing budding
Balance between• line tension• curvature energy
[R. Lipowsky, (1993)]
time
8 patch2 r
Bud-size: nm50/2bud R
TkB25 nm/1 BTk
Good range for coarse-
grained simulations!
![Page 91: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/91.jpg)
Movie of domain induced budding
16000 lipids, 50LJ between first 50 frames, then 500LJ for next 100 frames; 10kBT
![Page 92: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/92.jpg)
Vice versa…
pancakepancakeR
![Page 93: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/93.jpg)
Vice versa…
holeholeR
frame tension
line tension
RRE 22 Energy for constant frame tension: (Litster, 1975)
Energy for constant frame area:
R
A
RAAKE 2
)(
0
220
21
(Farago 2003; Tolpekina et al., 2004)
nucleation scenario
![Page 94: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/94.jpg)
wc=1.6, kBT=1.1, =15kBT
Membranes under tensionMeasure tension as a function of frame size (NAT ensemble)
![Page 95: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/95.jpg)
wc=1.6, kBT=1.1, =15kBT
Membranes under tensionMeasure tension as a function of frame size (NAT ensemble)
pore opens
membrane buckles
![Page 96: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/96.jpg)
Membranes under tensionMeasure tension as a function of frame size (NAT-ensemble)
wc=1.6, kBT=1.1, =15kBT
Simplest possible theory for pore opening: Harmonic extensibility plus line tension.O. Farago, J. Chem. Phys. 119, 596 (2003);T. V. Tolpekina, W. K. den Otter, and W. J. Briels, J. Chem. Phys. 121, 8014 (2004)
Three fit-parameter:
zero tension area
compressibility
rupture tension
6 mN/m3 kT/nm
![Page 97: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/97.jpg)
Lipid sorting in nature
Different cellular membranes are linked by many trafficking processes.
Yet, different membranes have distinctly different lipid compositions!
Why doesn’t the trafficking mess up the compositional gradients?
Idea: trafficking creates the gradient!
![Page 98: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/98.jpg)
Lipid sorting by curvature
50:50mixture
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 99: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/99.jpg)
Lipid sorting by curvature
50:50mixture
Simple model gives:
Density of big headed lipids in the outer
monolayer
Density of big headed lipids in the inner
monolayer
Linear in bilayer
curvature!
R
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 100: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/100.jpg)
Lipid sorting by curvature
50:50mixture
Simple model gives:
Density of big headed lipids in the inner
monolayer
Linear in bilayer
curvature!
in
outln
KDensity of big headed
lipids in the outer monolayer
R
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 101: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/101.jpg)
in
outln
K
How big is this effect?
45.0lnin
out
6.1in
out
21
21
in
out6.1 2
1out
21
in }
nm12R
0.11R
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 102: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/102.jpg)
in
outln
K
How big is this effect?
45.0lnin
out
6.1in
out
21
21
in
out6.1 2
1out
21
in }
nm12R
0.11
)(21e
1e 3/2
/2
21
RRkT
KkTKK
kTKK
OlMl
l
M
M
R
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 103: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/103.jpg)
in
outln
K
How big is this effect?
45.0lnin
out
6.1in
out
21
21
in
out6.1 2
1out
21
in }
nm12R
0.11
)(21e
1e 3/2
/2
21
RRkT
KkTKK
kTKK
OlMl
l
M
M
nm50R
0.03
That’s small !
R
I. R. Cooke and M. Deserno, to appear in Biophys. J.
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Neck regionsWhat happens in the highly curved regions where a bud is forming?
H.T. McMahon, J.L. Gallop, Nature 438, 590 (2005)
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 105: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/105.jpg)
Neck regionsWhat happens in the highly curved regions where a bud is forming?
H.T. McMahon, J.L. Gallop, Nature 438, 590 (2005)
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 106: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/106.jpg)
Neck regionsWhat happens in the highly curved regions where a bud is forming?
H.T. McMahon, J.L. Gallop, Nature 438, 590 (2005)
I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 107: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/107.jpg)
Neck regionsWhat happens in the highly curved regions where a bud is forming?
Density map of big-headed
lipids
Reason:mean curvature
is zero!Hardly any effect in the neck region! I. R. Cooke and M. Deserno, to appear in Biophys. J.
![Page 108: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/108.jpg)
Mediated interactions
Colloid
ColloidMembrane (=30kT)
B. Reynolds, G. Illya, V. Harmandaris, M. Deserno, in preparation
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Mediated interactions
does not stickto membranedoes not stickto membrane
sticks to membranesticks to membrane
zero lateral tension
zero lateral tension
Janus-colloids{}
B. Reynolds, G. Illya, V. Harmandaris, M. Deserno, in preparation
![Page 110: Lipid membranes between nano and micro: Markus Deserno Max-Planck-Institut für Polymerforschung, Mainz Cells and Materials, Workshop I: Membrane Protein.](https://reader038.fdocuments.in/reader038/viewer/2022110209/56649e575503460f94b4f19d/html5/thumbnails/110.jpg)
Mediated interactionsFix horizontal separation by
“computational laser tweezers”
Force on tweezer equalsforce between particles!
B. Reynolds, G. Illya, V. Harmandaris, M. Deserno, in preparation
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Force-distance-curves
distance
forc
e
B. Reynolds, G. Illya, V. Harmandaris, M. Deserno, in preparation
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Four-colloid-interaction
8000 lipids, 4 colloids; 50LJ between frames (448), 12kBT
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Four-colloid-interaction
8000 lipids, 4 colloids, 12kBT ; rotation of “final” configuration
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Summary
Simple solvent-free coarse-grained lipid model with pair interactions
Physics is correct, values are tunable
There are many more such questions!
Biological questions accessible, such as budding, coarsening, sorting
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GregoriaGregoria
VagelisVagelis(me)(me)
DavoodDavood
MartinMartinIraIra
BenBen
Acknowledgements
Kurt KremerKurt Kremer
Andreas Janshoff, Siegfried SteltenkampAndreas Janshoff, Siegfried Steltenkamp
Olaf Lenz, Friederike SchmidOlaf Lenz, Friederike Schmid
Oded Farago, Hiroshi NoguchiOded Farago, Hiroshi Noguchi
Jemal GuvenJemal Guven