Protein contents in biological membranes can explain abnormal solvation of charged and polar residues.

ABSTRACT: Transmembrane helices are generally believed to insert into membranes based on their hydrophobicity. Nevertheless, there are important exceptions where polar residues have great functional importance, for instance the S4 helix of voltage-gated ion channels. It has been shown experimentally that insertion can be accomplished by hydrophobic counterbalance, predicting an arginine insertion cost of only 2.5 kcal/mol, compared with 14.9 kcal/mol in cyclohexane. Previous simulations of pure bilayers have produced values close to the pure hydrocarbon, which has lead to spirited discussion about the experimental conditions. Here, we have performed computer simulations of models better mimicking biological membranes by explicitly including protein helices at mass fractions from 15% to 55%, as well

SUBMITTER: Johansson AC 

PROVIDER: S-EPMC2747180 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature