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G. Yu. Lomakina, P. A. Konik, N. N. Ugarova
Kinetics of the ATP hydrolysis by apyrase A
from Solanum Tuberosum
Abstract
Kinetics of the ATP hydrolysis by apyrase A
from Solanum tuberosum has been studied at pH 6.5 and 25 °C by
bioluminescent method. The kmfor ATP was defined
by 33 µM and the Vwas 0.37 µM/s. It was shown that the ATP
hydrolysis by apyrase takes place in two stages. The “fast” and “slow” stages
were described by each of the pseudo-fisrt-order kinetics. According to the
hypothesis proposed, an intermediate complex of apyrase with ADP which is
formed at the fast stage of the reaction, has catalytic activity in the
reaction of the ATP hydrolysis, but lower compared to free apyrase. This
complex hydrolyzes ATP in the “slow” stage of the reaction.
Key words:apyrase, adenosine-5′-triphosphate,
ATP, adenosine-5′-diphosphate, ADP, bioluminescent analysis.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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