Nys P S, Satarova D E, Podshibiakina L V, Korchagin V B, Savitskaia E M
Antibiotiki. 1980 Nov;25(11):808-15.
The kinetics of 7-phenylacetamidodesacetoxycephalosporanic acid (7-PADCA) catalyzed by immobilized penicillinamidase was studied. The kinetic and equilibrium parameters of the reaction were determined by analysis of the kinetic curves of the reaction product accumulation. Inhibition of the enzymatic reaction by the substrate and hydrolysis products was studied. It was found that the Michaelis complex completely lost its activity after attachment of the substrate second molecule to it. The values of the Michaelis constants, catalytic constant and constants of inhibition by the substrate and reaction products were determined: Km = (9.3 +/- 1.1) . 10(-5) M, kcat = (65 +/- 5) c-1, Ks = (1.4 +/- 0.1) . 10(-2) M, K1 (FAA) = (2.5 +/- 0.3) . 10(-4) M, K1 (7-ADCA) = (1.4 +/- 0.1) . 10(-1) M. The diffusion effect in the kinetic reaction catalyzed by immobilized penicillinamidase is discussed. The values of the Thiele modulus and the actual value of Km were calculated.
研究了固定化青霉素酰胺酶催化7-苯乙酰氨基去乙酰氧基头孢烷酸（7-PADCA）的动力学。通过分析反应产物积累的动力学曲线来确定反应的动力学和平衡参数。研究了底物和水解产物对酶促反应的抑制作用。发现米氏复合物在底物的第二个分子与其结合后完全失去活性。测定了米氏常数、催化常数以及底物和反应产物的抑制常数：Km = (9.3 +/- 1.1) . 10(-5) M，kcat = (65 +/- 5) c-1，Ks = (1.4 +/- 0.1) . 10(-2) M，K1（FAA）= (2.5 +/- 0.3) . 10(-4) M，K1（7-ADCA）= (1.4 +/- 0.1) . 10(-1) M。讨论了固定化青霉素酰胺酶催化的动力学反应中的扩散效应。计算了蒂勒模数和Km的实际值。
