Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions...
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Transcript of Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions...
![Page 1: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/1.jpg)
Cell Surface TargetingCell Surface Targeting
7/24/06
![Page 2: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/2.jpg)
AdaptamersAdaptamers
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QuestionsQuestions
Can we observe a gel shift with the conditions we’re using?
If so, are our aptamers binding protein?
![Page 4: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/4.jpg)
AnswersAnswers
Yes, we can observe streptavidin binding biotin.
No, neither of our aptamers appear to bind their targets. But we’re pretty sure of the reason.
![Page 5: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/5.jpg)
(Very) High Concentrations(Very) High Concentrations
S5: streptavidin aptamer + 5 nts
T5: thrombin aptamer + 5 nts
Protein staining2: .1% BSA 3: thrombin in .1% BSA4: thrombin + T5 in .1% BSA5: streptavidin + S56: streptavidin + S57: streptavidin + biotinylated oligosDNA staining9: biotinylated oligos 10: biotinylated oligos + streptavidin11: S512: S5 + streptavidin
Protein staining DNA staining
![Page 6: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/6.jpg)
FindingsFindings
Protein staining2: .1% BSA 3: thrombin in .1% BSA4: thrombin + T5 in .1% BSA5: streptavidin + S56: streptavidin + S57: streptavidin + biotinylated oligosDNA staining9: biotinylated oligos 10: biotinylated oligos + streptavidin11: S512: S5 + streptavidin
1) Observation of streptavidin binding biotin.
Protein staining DNA staining
![Page 7: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/7.jpg)
FindingsFindings
Protein staining2: .1% BSA 3: thrombin in .1% BSA4: thrombin + T5 in .1% BSA5: streptavidin + S56: streptavidin + S57: streptavidin + biotinylated oligosDNA staining9: biotinylated oligos 10: biotinylated oligos + streptavidin11: S512: S5 + streptavidin
1) Observation of streptavidin binding biotin.2) Streptavidin is not binding S5.
Protein staining DNA staining
![Page 8: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/8.jpg)
FindingsFindings
Protein staining2: .1% BSA 3: thrombin in .1% BSA4: thrombin + T5 in .1% BSA5: streptavidin + S56: streptavidin + S57: streptavidin + biotinylated oligosDNA staining9: biotinylated oligos 10: biotinylated oligos + streptavidin11: S512: S5 + streptavidin
1) Observation of streptavidin binding biotin.2) Streptavidin is not binding S5.3) BSA is actually responsible for bands in lanes with thrombin.
![Page 9: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/9.jpg)
FindingsFindings
Protein staining2: .1% BSA 3: thrombin in .1% BSA4: thrombin + T5 in .1% BSA5: streptavidin + S56: streptavidin + S57: streptavidin + biotinylated oligosDNA staining9: biotinylated oligos 10: biotinylated oligos + streptavidin11: S512: S5 + streptavidin
1) Observation of streptavidin binding biotin.2) Streptavidin is not binding S5.3) BSA is actually responsible for bands in lanes with thrombin.4) Is there a thrombin shift? Unclear.
![Page 10: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/10.jpg)
Moderate ConcentrationModerate Concentration
Protein staining2: thrombin 3: thrombin + T54: streptavidin + S55: streptavidin + S56: streptavidin + biotinylated oligosDNA staining8: nothing + loading dye 9: T510: T5 + thrombin11: S512: S5 + streptavidin
4) Thrombin shift? No.
Protein staining DNA staining
![Page 11: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/11.jpg)
Moderate ConcentrationModerate Concentration
Protein staining2: thrombin 3: thrombin + T54: streptavidin + S55: streptavidin + S56: streptavidin + biotinylated oligosDNA staining8: nothing + loading dye 9: T510: T5 + thrombin11: S512: S5 + streptavidin
Question: What is responsible for these bands?
Protein staining DNA staining
![Page 12: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/12.jpg)
More answersMore answers
Have been using bovine thrombin, not human thrombin.
Secondary structure issues: everyone else denatures their aptamers prior to incubation with protein
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Next:Next:
Change the thrombin, add denaturationIf it works,
– try adaptamer experiments; also, redesign adaptamers to avoid secondary structure conflicts.
– Order aptamers that can bind a cell.If it doesn’t,
– Put on thinking cap.
![Page 14: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/14.jpg)
![Page 15: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/15.jpg)
Sequencing resultsSequencing results Clones from Ting lab: StrepW, StrepH, StrepD BioBrick’d and sent out for sequencing last week
Results– StrepW: Correct sequence 1-444 from both forward/reverse reactions– StrepH: One mutation at bp 344, T to C
GCT to GCC, silent mutation for alanine– StrepD: Correct sequence 1-409 from forward reaction, correct sequence
410-444 from reverse reaction
Performed midipreps
![Page 16: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/16.jpg)
BioBricks for Lpp-OmpABioBricks for Lpp-OmpA
OmpA PCR
46-66 100
1000
400
200
500
1650
46-159
full
300
Lpp PCR
100
400
200
500
300
1-29
full full+stop
XbaI/PstI digest
Lpp1-29
OmpA46-66
OmpA46-159
100
400
200
500
300
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BioBricks for SCD streptavidinBioBricks for SCD streptavidin Single-chain dimer
clones from Aslan lab– SCD-NM– C2– E2
E XStrepSCDF
S PStrepSCDR
StrepSCDMF
StrepSCDMR
1 825
PstI site, 620CTGCAG CTGCGG
100
400
200
500
300
SCD-NM C2 E2
MF/R
F/MR
F/Rnon-mut
650850
1000
1st PCR
400
300
SCD-NM C2 E2
F/R
Crossover PCR
sent out for sequencing
![Page 18: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/18.jpg)
Sequencing resultsSequencing results Homology in bp regions ~1-250 and ~550-800 Why?
– Single– Chain– Dimer
Forward primer annealing region– Bp 004-023: gaggccaacgccaagaagtc– Bp 538-557: gaggccaacgcctggaagtc
Explains double PCR products with F/MR and F/R primers Does not explain single crossover PCR product
![Page 19: Cell Surface Targeting 7/24/06. Adaptamers Questions Can we observe a gel shift with the conditions we’re using? If so, are our aptamers binding protein?](https://reader035.fdocuments.in/reader035/viewer/2022062315/5697bfe91a28abf838cb6ec8/html5/thumbnails/19.jpg)
Progress/plansProgress/plans
Midipreps of StrepW, StrepH, StrepD BioBricks of Lpp(1-29), OmpA(46-66) and (46-159);
sent out for sequencing
Confirm sequences of Lpp and OmpA parts; midiprep. Digest and assembly. Figure out solution for StrepSCD PCR
– Design new primers Anneal upstream on plasmid PCR in separate parts and assemble