Generation and isolation of cyanobacterial inside-out thylakoid vesicles.

A method has been designed to prepare inside-out thylakoid vesicles from a cyanobacterial species (Phormidium laminosum). Everted thylakoid vesicles could be generated by Yeda press treatment after induced membrane pairing. Membrane pairing was induced either by addition of high concentrations of Mg2+ ions or by lowering the pH of the fragmentation media. The inside-out vesicles were isolated by aqueous polymer two-phase partition. The membrane orientation was determined by proton translocation studies and freeze-fracture electron microscopy.