Proteins in Liquid-Crystalline Phase Lipid Bilayers. A Study Using Fluorescence Recovery after Photobleachingt

ABSTRACT: The translational diffusion of bovine rhodopsin, the Caz+-activated adenosinetriphosphatase of rabbit muscle sarcoplasmic reticulum, and the acetylcholine receptor mo-nomer of Torpedo marmorata has been examined at a high dilution (molar ratios of lipid/protein 1 3000/1) in liquid-crystalline phase phospholipid bilayer membranes by using the fluorescence recovery after photobleaching technique. These integral membrane proteins having molecular weights of about 37 000 for rhodopsin, about 100000 for the adenosinetri-phosphatase, and about 250 000 for the acetylcholine receptor were reconstituted into membranes of dimyristoyl-phosphatidylcholine (rhodopsin and acetylcholine receptor), soybean lipids (acetylcholine receptor), and a total lipid extrac