Jana Snehasis, Deb J K
Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi 110016, India.
Biotechnol Lett. 2005 Apr;27(7):519-24. doi: 10.1007/s10529-005-2544-9.
Bacterial resistance to the aminoglycoside antibiotics is manifested primarily by enzymic modification of these drugs. One important mechanism of streptomycin modification is through ATP-dependent O-adenylation, catalyzed by streptomycin adenylyltransferase. Initial velocity patterns deduced from steady state kinetics indicate a sequential mechanism. Dead-end inhibition by tobramycin and neomycin is non-competitive versus streptomycin and uncompetitive versus ATP, indicative of ordered substrate binding where ATP binds first and then streptomycin. These results surmise that streptomycin adenylyltransferase follows an ordered, sequential kinetic mechanism in which one substrate (ATP) binds prior to the antibiotic and pyrophosphate is released prior to formation of AMP-streptomycin.
细菌对氨基糖苷类抗生素的耐药性主要表现为这些药物的酶促修饰。链霉素修饰的一个重要机制是通过由链霉素腺苷酸转移酶催化的ATP依赖性O-腺苷化。从稳态动力学推导的初速度模式表明是一种有序机制。妥布霉素和新霉素的终产物抑制对链霉素是非竞争性的，对ATP是反竞争性的，表明底物按顺序结合，其中ATP先结合，然后是链霉素。这些结果推测，链霉素腺苷酸转移酶遵循一种有序的、顺序动力学机制，其中一种底物（ATP）在抗生素之前结合，焦磷酸在形成AMP-链霉素之前释放。
