31P‐Nuclear Magnetic Resonance and Freeze‐Fracture Electron Microscopic Studies on Reconstituted Bacteriorhodopsin Vesicles

Abstract

Bacteriorhodopsin has been reconstituted into egg‐phosphatidylcholine vesicles by various methods. The resulting preparations have been analyzed on density gradients and by freeze‐fracture electron microscopy. The homogeneity of the vesicle preparations and the light‐induced intravesicular pH changes have been studied by 31P‐NMR, using glucose 6‐phosphate as pH probe. It is concluded that bacteriorhodopsin is incorporated in the inside‐out mode in vesicles up to about 100 nm. Above this diameter, more or less random insertion takes place. Copyright © 1981, Wiley Blackwell. All rights reserved