O.V. Mosin, I. Ignatov

Bacteriorhodopsin - photo-transforming transmembran protein with molecular mass 26,7 kDa representing chromoprotein connected with the Schiff base at the lysine-216 residue with a chromophore group consists of equimolar mixture of 13-cys- and completely 13-trance-retinol С20-carotenoid - analogue of the vitamin A, defining purple-red colour of halobacteria. Despite the structurall-functional level and organization of bacteriorhodopsin in purple membranes of halobacteria is well studied, bacteriorhodopsin still remains in the focus of attention of bio-and nanotechnology because of high photosensitivity and resolution, and, therefore, it is used in molecular bioelectronics as a natural photochrome material as operated light or electric impulses in computer modules and optical systems. Besides, bacteriorhodopsin seems to be very attractive as modelling object for the research connected with the studying of functional activity and structural properties of photo-transforming membrain proteins as a part of artificial native energo- and photo-transforming membranes. Bacteriorhodopsin was allocated in micropreparative amounts (810 mg) from purple membranes of halobacterium Halobacterium halobium by cultivation of the halobacterium on special selected synthetic growth medium, breaking down of cell by osmolysis in distillid water, processing of bacterial biomass by ultrasound at 22 kHz (5 min), ribonuclease tratment, ethanol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, and the subsequent solubilization of final protein with 0.5% SDS-Na and its fractionation by methanol. The homogenity of bacteriorhodopsin was proved by combination of preparative and analytical protein methods including elecrtophoresis in 12.5% PAAG with 0.1% SDS-Na and gel filtration chromatography on Sephadex G-200.