期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1976
卷号：73
期号：2
页码：476-480
DOI：10.1073/pnas.73.2.476
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Fast reaction techniques were used to study the kinetics of protein fluorescence intensity changes that are associated with the reactions of unadenylylated Escherichia coli glutamine synthetase [L-glutamate: ammonia ligase (ADP-forming), EC 6.3.1.2 ] with its substrates. It was established that the synthesis of glutamine occurs by a stepwise mechanism. During the catalytic process two fluorometrically distinct intermediates were observed. Both forward and reverse rate constants which lead to the formation and consumption of these intermediates were evaluated. The catalytic rate constant, kc, which was calculated from these rate constants agrees well with the values of kc which were determined by direct measurement of the overall biosynthetic activities by means of stopped-flow technique or the steady-state assay method.
