Abstract

Membrane Thickness and Charged Protein-Lipid Interactions

Author(s): Alena Johnson

Charged amino acids are known to influence the functions of integral and peripheral membrane proteins, as well as cell disrupting peptides. Despite the fact that atomistic molecular dynamics studies have given light on the mechanics of charged protein group membrane binding and translocation, the impact of the full range of membrane Physio-chemical properties and topologies has yet to be addressed. In this research, we looked at how an Arginine (Arg) side chain analogue moved through saturated phosphatidylcholine (PC) bilayers with hydrocarbon tail lengths ranging from 10 to 18 carbons. The free energy profiles all exhibit sharp climbs as penetration into the hydrocarbon core increases, with predictable shifts between bilayers of various thickness, culminating in a barrier reduction from 26 kcal/mol for 18 carbons to 6 kcal/mol for 10 carbons.