摘要
利用分光光度法研究 3种由革兰氏阴性菌产生的 TEM型 β-内酰胺酶的动力学。以 L- B作图法求取 Km 和 Vmax。TEM- 1、TEM- 2对青霉素类有较强水解作用 ,对第一代头孢菌素和第三代头孢菌素头孢哌酮也有一定程度水解 ,而对第二代头孢菌素头孢呋新及其它第三代头孢菌素均无水解作用 ;而 TEM- 5对青霉素类及第一、二、三代头孢菌素均有不同程度的水解 ;TEM型酶的最适 p H值为 6 .6～ 7.4,最适反应温度为35℃～ 40℃。不同 TEM型酶其水解底物轮廓有较大差异 ,温度、p
To study the enzyme kinetics of 3 types of TEM β-lactamases extracted from Gram-negativebacteria by spectrophotometry. Michaelis constant (K m) and maximal velocity (V max) were obtained from L-B plot. The penicillins, the first generation cephalosporins and cefoperazone were hydrolyzed by TEM-1 and TEM-2, but TEM-1 and TEM-2 were unable to hydrolyze the second generation cephalosporins cefuroxime and other of the third generation cephalosporins. The penicillins, the first, second and third generation cephalosporins were hydrolyzed by TEM-5 β-lactamase in different degree. The optimal pH of TEM type enzyme were 6.6~7.4, and the optimal temperature were 35~40℃. There were differences between substrate profiles of TEM-1, TEM-2 and TEM-5 β-lactamase. The activities of 3 types of TEM β-lactamases were affected by temperature and pH value.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2001年第6期460-463,共4页
Chinese Journal of Antibiotics
