文章基本信息

标题：Subunit neighbor interactions in enzyme kinetics: half-of-the-sites reactivity in a dimer
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作者：T L Hill ; A Levitzki
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：1980
卷号：77
期号：10
页码：5741-5745
DOI：10.1073/pnas.77.10.5741
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We consider an isologous enzyme dimer in which the subunits, if operating independently, would obey Michaelis-Menten kinetics. However, because of neighbor interactions, the rate constants of the kinetic cycle in either subunit depend on the state (E or ES) of the other subunit. The steady-state behavior of this dimer system, with interactions, is investigated. In what is probably the most important special case, ES x ES is destabilized considerably by the neighbor interaction compared to E x ES. This leads to half-of-the-sites reactivity (one subunit is in state ES; the other subunit cycles between E and ES), negative cooperativity, and a considerable enhancement of enzyme activity relative to the activity of independent subunits.