title: Melittin and the 8-26 fragment. Differences in ionophoric properties as measured by monolayer method.
abstract: Melittin is a major (approximately 50%) protein component of bee venom. This peptide is an amphiphilic protein, because, while the amino acid residues 1-20 are predominantly hydrophobic (with the exception of Lys-7), residues 21-26 are hydrophilic. The binding properties to vesicles and lipid bilayers of melittin have provided much useful information regarding biological (hemolytic) activity (Habermann, E., 1972, Science [Wash. DC], 177:314-322). Recent studies have convincingly established that the melittin monolayer (at air-water interface) model membrane system allows one to analyze the various forces present in such structures. We present comparative monolayer studies of melittin and the peptide fragment 8-26 regarding the channel formation for the selective anion (Cl-) penetration in monolayers, analogous to melittin (tetramer) channel function in lipid bilayer. The differences in surface pressure and surface potential of monolayers between native melittin and the 8-26 fragment suggest that these may be ascribed to Lys-7.
mesh_terms: D001514:Bee Venoms; D007700:Kinetics; D008051:Lipid Bilayers; D046911:Macromolecular Substances; D008555:Melitten; D010446:Peptide Fragments
chemical_list: D001514:Bee Venoms; D008051:Lipid Bilayers; D046911:Macromolecular Substances; D010446:Peptide Fragments; D008555:Melitten; C042214:melittin(8-26)