Protein-phospholipid-cholesterol interaction in the photolysis of invertebrate rhodopsin

Abstract

ABSTRACT: Three aspects of protein-phospholipid-cholesterol interaction in microvillar membranes of octopus photoreceptor cells were studied: (1) the effect of hydrophobic environment on the kinetics of thermal transformation in the photolysis of rhodopsin; (2) effects of cholesterol in microvillar membranes on protein-lipid interaction; (3) the effect of membrane pro-teins on the dynamic properties of lipids in membranes. Dynamic properties of hydrophobic environments were ob-served with electron spin resonance spectroscopy with various lipid spin-labels. The kinetics of thermal transformation of mesorhodopsin to metarhodopsin was followed by flash pho-tolysis experiments. The thermal stability of mesorhodopsin was followed by low-temperature spectrophotometry. The rate of transformation is influenced by the properties of both hy-drophobic environments and temperature. The effect of the