Self-Assembly of Surfactant-like Peptides

Steve S. Santoso, Sylvain Vauthey & Shuguang Zhang

Center for Biomedical EngineeringMassachusetts Institute of Technology

Nanostructures• Structures ranging from 1 to 100 nm• Sub-micrometer science and engineering that combine

multiple disciplines:• Chemistry• Biology• Physics• Material science• Engineering

• How to build / design nanostructures?• Want the atomic selectivity of synthetic chemistry yet the

expandability of engineering

• Molecular self-assembly may be useful

Self-assembly processes common in biological systems:• Cell membrane• Multi-component cellular machinery: ribosome• Protein folding

Self-assembly involves non-covalent bonding• van der Waals• hydrogen bonds• dipolar forces

dynamic process

[Ac]-VVVVVVDSix hydrophobic valines (tail)One polar aspartic acid (head)

2 nm

Surfactant-like peptides

Preliminary experiments and results• Some condition screening

• Use: dynamic light scattering (DLS), TEM

• Found larger structures for some conditions:

Cryo-TEM:

300 nm

Nanotubes are not the structure with energetic global minimum:

RF

• Controlled delivery of small chemicals• Use nanovesicle to study replication of biological materials in an enclosed environment

Nanovesicle

550 nm

150 nm

Summary• Peptide surfactants are promising substrates for advanced material and its application.

• Cost-effective• Certain structures will form under certain environmental and chemical conditions

• Tunable

• Biological origin may be advantageous for medical application• A good system to study self-assembly.