[Inhibition of bacterial luminescence by cytochrome P-450 substrates]. / Ingibirovanie bakterial'noi liuminestsentsii substratami tsitokhroma P-450.

The mechanisms of luminescence quenching by various drugs, e.g. dimethylaniline, ethylmorphine, hexobarbital and aminopyrine, which are effective inhibitors of luminescence both in intact cells and in bacterial luciferase, were studied. It was shown that the inhibition of luminescence occurs due to competition of the bacterial luminescence system substrate--aliphatic aldehyde in cytochrome P-450. The functional similarity of the bacterial luminescence system to the microsomal hydroxylation system is postulated.

[Respiration toxins as inhibitors of ion transport, supported by ATP hydrolysis, in mitochondria]. / Dykhatel'nye iady kak ingibitory transporta ionov, podderzhivaemogo gidrolizom ATR v mitokhondriiakh.

Effect of respiration toxins is studied on some properties of mitochondrial membranes and functions connected with ion transport for the expence of ATP energy. The combination of three respiration inhibitors (cyanide, antimycin and rotenone) was shown to develope the following effects: 1) the inhibition of K+ accumulation by mitochondria at the presence of ATP and valinomycin; 2) the decrease in acidification of non-mitochondrial space, accompanying to the K+ transport; 3) the activation of latent mitochondrial ATPase; 4) the inhibition of DNP-stimulated ATPase; 5) the inhibition of mitochondria swelling, caused by K+, Ca2+, or dimethyldibenzylammonium (DDA+) at the presence of ATP+phopshate (or acetate); 6) the stimulation of passive mitochondria swelling in 0.1 MNH4NO3; 7) the inhibition of ATP-induced contraction of mitochondria, swelling in NH4NO3. The data obtained are discussed in a wiev of the conception, which suggests that the attaching of inhibitors to respiration enzymes changes the configuration of the latters, thus disturbing natural structural bond of these enzymes with other protein components of the membrane. The latter can result in the impair of electroisolating membrane properties, in the increase of its conductivity for H+ and other ions, and in the decrease of Vm values of some enzymatic reaction, which are not directly connected with the respiration chain (such as ATPase reaction).