SURFACTOSOMES - A NOVEL-APPROACH TO THE RECONSTITUTION AND 2-D CRYSTALLIZATION OF MEMBRANE-PROTEINS

The formation of vesicle-like structures (termed surfactosomes) and la mellar sheets from solutions containing ammonium perfluoroocanoate (AP FO) is illustrated using conventional and cryo-transmission electron m icroscopy. It is shown how this detergent can be used for the solubili sation, reconstitution, and 2-D crystallisation of membrane proteins a s demonstrated for the major protein of the membrane sector of the V-t ype H+-ATPase (16-kDa protein). Electron microscopical analysis of 2-D crystals of the 16-kDa protein (a = b = 13.0 +/- 0.2 nm with gamma = 90 degrees and p4 projection symmetry) revealed a unit cell comprising four dimeric complexes of the 16-kDa protein the significance of whic h is discussed.