Vojtísek V, Slezák J
Folia Microbiol (Praha). 1975;20(3):224-30. doi: 10.1007/BF02876783.
Substrate specificity of the bacterial penicillinamidohydrolase (penicillinacylase, EC 3.5.1.11) from Escherichia coli was determined by measuring initial rates of enzyme hydrolysis of different substrates within zero order kinetics. Some N-phenylacetyl derivatives of amino acids and amides of phenylacetic acid and phenoxyacetic acid of different substituted amides of these acids or amides, structurally and chemically similar to these compounds, served as substrates. Significant differences in ratios of initial rates of the enzyme hydrolysis of different substrates were found using a toluenized suspension of bacterial cells or a crude enzyme preparation, in spite of the fact that the enzyme is localized between the cell wall and cytoplasmic membrane, in the so-called periplasmic space. N-phenylacetyl derivatives are the most rapidly hydrolyzed substrates. Beta-phenylpropionamide and 4-phenylbutyramide were not utilized as substrates. The substrate specificity of the enzyme is discussed with respect to a possible use of certain colourless compounds as substrates, hydrolysis of which yields chromophor products suitable for a simple and rapid assay of the enzyme activity.
通过在零级动力学条件下测量不同底物的酶促水解初始速率，确定了来自大肠杆菌的细菌青霉素酰胺水解酶（青霉素酰化酶，EC 3.5.1.11）的底物特异性。一些氨基酸的N-苯乙酰基衍生物以及苯乙酸和苯氧基乙酸与这些酸或酰胺的不同取代酰胺形成的酰胺，在结构和化学性质上与这些化合物相似，用作底物。尽管该酶位于细胞壁和细胞质膜之间，即所谓的周质空间，但使用细菌细胞的甲苯化悬浮液或粗酶制剂时，发现不同底物的酶促水解初始速率之比存在显著差异。N-苯乙酰基衍生物是水解最快的底物。β-苯丙酰胺和4-苯丁酰胺未被用作底物。关于某些无色化合物作为底物的可能用途，讨论了该酶的底物特异性，这些化合物水解后会产生适合简单快速测定酶活性的发色产物。
