牛胰多肽(Bovine Pancreatic Polypeptide)和DMPC脂质体相互作用的荧光研究

本文用多种荧光探剂标记脂质体,通过荧光光谱、荧光强度以及荧光偏振的变化,阐明牛胰多肽与磷脂之间存在较强的结合,这种结合主要是静电相互作用与疏水相互作用.牛胰多肽与磷脂结合后,使膜结构稳定,这可能是牛胰多肽具有细胞保护作用的原因之一.

FLUORESCENCE STUDIES ON INTERACTION OF BPP WITH DMPC VESICLES

The present paper reports the interaction of bovine pancreatic polypeptide (BPP)with phospholipids by fluorescence methods.The results show:(1)fluor-escence spectra of DMPC Vesicles labeled with DNS-PE, 2-AS,6-AS, 12-AS reveal red shift and blue shift respectively,fluorescence intensity increases. (2) BPP prefers binding with zwitherionic DMPC to negatively charged PA.The disassociation constants are 2.8×10-7M and 5.0×10-7M respectively.(3) BPP decreased the P values of DPH-labeled DMPC below its phase transition tem-perature(Tm).The obvious Tm of DMPC is not observed with the binding of BPP to it.It seems that the binding of BPP to phospholipids are caused not only by electrostatic lipid-peptide interactionbut also hydrophobic interaction.This binding perhaps is an important factor by which BPP shows protection to pancreas cells.