Vesicle binding and structural properties of luteinizing hormoe releasing hormone (LHRH)

Abstract

The interaction between phosphatidylserine multilamellar vesicle (PSMLV) and synthetic luteinizing hormone releasing hormone (LHRH) was investigated by intrinsic fluorescence and centrifugal separation of PS MLV-LHRH complexes. PS MLV induced a blue-shift in the wavelength of maximum emission of fluorescence of LHRH by about 7 nm. The influence of PS MLV on the quenching of the tryptophan in LHRH by sodium iodide (NaI) was studied. PS MLV was found to protect LHRH from the iodide quenching. The conformation of LHRH was investigated by circular dichroic measurements. The Greenfield-Fasman and the Chang-Wu-Yang methods were used for the analysis of CD spectra. It was found that LHRH has appreciable $\beta$-structure even in aqueous solution. The $\beta$-strcture content increased significantly upon binding to amphihpilic surface.