Hydrophobic interactions of peptides with membrane interfaces

The thermodynamic principles underlying the structural stability of membran e proteins are difficult to obtain directly from whole proteins because of intractable problems related to insolubility in the aqueous phase and extre me stability in the membrane phase. The principles must therefore be surmis ed from studies of the interactions of small peptides with lipid bilayers. This review is concerned with the hydrophobic interactions of such peptides with the interfacial regions of lipid bilayers. We first develop a general framework for thinking about the thermodynamics of membrane protein stabil ity that centers on interfacial interactions and review the structural and chemical evidence that supports this interface-centered point of view. We t hen describe an experimentally determined whole-residue interfacial hydroph obicity scale that reveals the central role of the peptide bond in partitio ning and folding. Finally, we consider the complexity and diversity of inte rfacial interactions revealed by differences between side-chain hydrophobic ities determined using different classes of peptides. (C) 1998 Elsevier Sci ence B.V. All rights reserved.