Premium
Fluorescence and CD studies on the conformation of the gastrin releasing peptide in solution and in the presence of model membranes
Author(s) -
Cavatorta P.,
Sartor G.,
Neyroz P.,
Farruggia C.,
Franzoni L.,
Szabo A. G.,
Spisni A.
Publication year - 1991
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360310610
Subject(s) - chemistry , vesicle , peptide , micelle , random coil , gastrin , fluorescence , membrane , biophysics , conformational isomerism , crystallography , protein secondary structure , biochemistry , organic chemistry , aqueous solution , molecule , physics , quantum mechanics , secretion , biology
The conformation of the heptacosapeptide hormone, gastrin releasing peptide, has been studied in buffer and in the presence of lipids, using static and dynamic fluorescence and CD. The results obtained show that, in buffer, the hormone exists in a collection of flexible, random coil type conformers, characterized by a β‐turn between residues 14‐19. On the other hand, organic solvents can induce some degree of ordered secondary structure in the peptide chain. The marked changes, observed in CD and fluorescence spectra upon addition of lysolecitin micelles and dimyristoylphosphatidylserine vesicles, clearly show that the peptide interacts with lipids, assuming a lipid specific configuration. Interestingly, no significative spectroscopic changes are produced by exposure to dimyristoylphosphatidylcholine vesicles both in the gel and liquid‐chrystalline phases, suggesting a requirement for negatively charged lipids during the process of hormone–membrane interaction.