[Proteins of bacterial membranes. NADH-dehydrogenase from the cells of Acholeplasma laidlawii].

Using ion-exchange chromatography on DEAE-cellulose and gel filtration, a purified NADH-dehydrogenase was prepared from cell membranes of A. laidlawii. The enzyme specific activity exceeds the activity of the membrane preparation 45-fold. The enzyme is thermolabile and sensitive to lecithine. Electrophoresis of the enzyme preparation in the presence of Na-DS resulted in two proteins with Mr of 65 000 and 72 000. Specific staining of the gels with triphenyltetrasolium chloride in the presence of Triton X-100 revealed two protein bands, while in the presence of Triton X-100 and urea only one protein band was produced.