TCB Seminar

Peptide Bilayer-Now Really? What's Next?

Professor John Tomich, Ph.D.
Biochemistry and Molecular Biophysics
Kansas State University
Manhattan, KS

Monday, April 16, 2018
3:00 pm
3269 Beckman Institute

Abstract

A number of years ago we stumbled on a sequence that formed micelles at low pH. Based on our understanding of self-assembling lipids, we reasoned that if our single chain peptide formed micelles a branched sequence might form vesicles delimited by a bilayer. In contrast to their counterpart liposomes, our vesicular assemblies are more stable and biocompatible. In water this peptide forms 10 nm diameter nanocapsules. They are readily taken up by cells in vitro and in vivo and have been used to encapsulate and deliver radionuclides, small proteins and dye molecules. These cationic capsules also bind and deliver negatively charged nucleic acids bound to their outer surface and have proved to be a promising delivery system for DNA vaccines and RNAi to target specific insect vector species. However after numerous reviewed publications we still get asked, “How do you know it’s a bilayer?”. In this talk I want to present our latest findings that should satisfy our doubters. Biophysical analyses and computer simulations on the self-assembling branched peptide - (Ac-FLIVIGSII)2-K-K4 will be presented. The peptide has also been conjugated to gold nanoparticles that provides a surface where the bilayer leaflets are laid down sequentially, affording additional methods for characterizing the assembly.