Towards a better understanding of membrane proteins : Synthesis and biophysical characterization of oligomeric model peptides

Abstract

Membrane protein research is an important, but problem-riddled field. One method to obtain knowledge on this class of proteins is by studying the molecular mechanisms underlying their structure and function using simple model systems. An example of a model system with which a better understanding of membrane proteins has been achieved, is that of ?-helical WALP peptides (Ac-GWW(LA)nLWWA-NH2) in vesicles of synthetic lipids. However, membrane proteins usually have multiple membrane spanning segments. To better mimic this situation, covalent assemblies of WALP-peptides were synthesized. As a first step towards a systematic study of the effect of oligomerization on peptide-lipid interactions, two types of dimers were biophysically characterized. The comparison of the helix-lipid interactions of the dimers to that of their monomeric counterparts provides the first indication of the influence of cross sectional diameter and helix-helix interactions on helix orientation and lipid interactions.