FORMATION OF STABLE LIPOSOMES FROM LIPID EXTRACTS OF ARCHAEOBACTERIA (ARCHAEA)

摘要

Novel ether lipids were obtained from methanogenic (Methanospirillum hungatei, Methanococcus jannaschii, Methanococcus voltae, Methanosarcina mazei, and Methanobrevibacter smithii), and extremely halophilic (Halobacterium cutirubrum) representatives of the archaeobacteria. Several of the ether lipids produced by Methanospirillum and Methanosarcina genera were purified and characterized structurally for the first time. Unilamellar liposomes were prepared from emulsions of the total polar - ether lipid extracts of such bacteria by pressure extrusion through membranes of various pore sizes. Liposome populations were shown by dynamic light scattering and electron microscopy to range in size depending on the pore size of the filter, on the source of the lipids, and on the composition of the suspending buffer medium. In all cases the size ranges indicated highly homogeneous preparations. Leakage of entrapped fluorescent or radioactive compounds established that the ether liposomes were stable to attack by phospholipase A2 and B, and were stable for at least 60 days to storage in an atmosphere of air. The detergent dialysis method of forming liposomes also produced unilamellar liposomes from most of the archaeobacterial total polar lipid extracts which were tested.