文章基本信息

标题：Subunit interaction during catalysis: alternating site cooperativity in photophosphorylation shown by substrate modulation of [18O]ATP species formation
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作者：D D Hackney ; G Rosen ; P D Boyer 等
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：1979
卷号：76
期号：8
页码：3646-3650
DOI：10.1073/pnas.76.8.3646
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Pronounced substrate modulation of incorporation of water oxygen into ATP formed by photophosphorylation is observed, as measured by 31P NMR analysis of products formed from ADP and highly 18O-labeled Pi. A marked increase occurs in oxygen exchange per ATP formed as ADP or Pi concentration is decreased. This is explainable by the binding-change mechanism for ATP synthesis, in which the energy-linked release of ATP from one site requires the binding of ADP and Pi at an alternate site. Analysis of the distribution of 18O-labeled species arising from the ATP formed eliminates explanations for substrate modulation based on preexisting or induced enzyme heterogeneity. Furthermore, the results, together with other related findings, make participation of control sites unlikely. The occurrence of alternating site catalysis cooperativity in ATP synthesis by chloroplasts thus appears to be reasonably well established.