G. V. Danylovych1, T. G. Gruzina2, Z. R. Ulberg2, S. O. Kosterin1
Accumulation of gold in cells of Bacillus sр. B4253 can be directly or indirectly connected with activity of bacteria plasma membrane basal Mg2+-АТРаse. Therefore this work deals with a comparative analysis of kinetic properties of plasma membrane basal аzide-resistant Mg2+-dependent АТР-hydrolase activity of B. sр. B4253 and B. sр. B4851 capable to gold accumulation and not capable to this process, accordingly. It is shown, that by a number of kinetic parameters – specific fermentative activity, initial speed of reaction of hydrolysis АТР (V0), Mixaelis constant (Km), the maximal initial speed by Mg2+ (VMg) and by АТР (VАТР), optimum concentration of АТР ([ATP]opt), рНmax, sensitivity to action of the thapsigargine and eosine Y?– bacteria membranes basal Mg2+-АТРаse activity accumulating gold, and the bacteria not capable to this process, are identical. But by some parameters they differ: Mg2+-АТРаse activity of membranes of the bacteria which do not accumulate gold, has three times greater affinity for Mg ions and smaller value [Mg]opt. The inhibition effect of ionic gold (10-4–3·10-4?M) is shown on аzide-sensitive (Н+-АТРase) and аzide-resistant (Mg2+-АТРаse) components Mg2+-dependent АТР-hydrolase activity in fraction of plasma membranes of microorganisms Bacillus accumulating gold, and not capable to this process. Colloid gold (0.0002–4 µg/ml) stimulates activity of Н+-АТРаse and Mg2+-АТРаse in a membrane of the bacteria accumulating gold 1.5–2 times, and does not influence activity of АТРаses of a membrane of the bacteria which do not accumulate gold.
Key words: ionic and colloid gold, Н+-АТРаse, Mg2+-АТРаse, Bacillus sр. B4253, B. sр. B4851.
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