Influence of α-helices on the emulsifying properties of proteins

Abstract

A peptide derived from apomyoglobin by cyanogen bromide cleavage was found to be an active emulsifier. This molecule, peptide 1-55, has two potential amphipathic α-helices and a hydrophilic C-terminal domain. The importance of each of these domains to the emulsifying properties of this molecule was investigated by testing the products of gene constructs based on the sequence of peptide 1-55, but lacking one of the three domains. The emulsifying activity of the peptides lacking either of the α-helices was correlated with the hydrophobic moments of their respective helices. The hydrophobic moment is a measure of the amphipathicity of α-helices; a hydrophobic moment analysis of other emulsifying peptides supports the hypothesis that a high hydrophobic moment contributes to good emulsifying properties in a molecule which contains α-helices.