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 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.