Membrane vesicles fromSynechocystis 6803 showing proton and electron transport and high ATP synthase activities.

A simple procedure for the preparation of well-coupled and stable membrane vesicles from the transformable cyanobacteriumSynechocystis 6803 is described with the primary aim of producing vesicles suitable for the study of photosynthetic electron transport and phosphorylation. Spheroplasts were obtained from the cyanobacterium by lysozyme treatment and stored untill prior to measurement, thylakoid vesicles were obtained by osmotic shock. These vesicles showed very high and stable ATP synthesis rates either driven by light or by acid-base transition, and also performed light-induced ATP hydrolysis and linear electron transport. Formation of a proton gradient is studied by aminoacridines.