NEGATIVE COOPERATIVITY IN REGULATORY ENZYMES
NEGATIVE COOPERATIVITY IN REGULATORY ENZYMES
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DOI：
10.1073/pnas.62.4.1121
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发表时间：
1969-01-01
影响因子：
11.1
通讯作者：
KOSHLAND, DE
中科院分区：
文献类型：
--
作者：
LEVITZKI, A;KOSHLAND, DE
CTP合成酶是一种含有调节位点的变构酶，它具有负协同效应。因此，相同的酶对GTP（效应物）和谷氨酰胺（底物）表现出负协同性，而对ATP和UTP（两种底物）表现出正协同性。在描绘这些现象的过程中，开发了负协同性的诊断程序。将这些程序应用于其他酶表明，负协同性是其中许多酶的特征。这些发现为亚基相互作用的顺序模型提供了强有力的支持，该模型假定配体诱导的构象变化是酶中的调节和合作现象的原因。
Negative cooperativity has been observed in CTP synthetase, an allosteric enzyme which contains a regulatory site. Thus, the same enzyme exhibits negative cooperativity for GTP (an effector) and glutamine (a substrate) and positive cooperativity for ATP and UTP (both substrates). In the process of the delineation of these phenomena, diagnostic procedures for negative cooperativity were developed. Application of these procedures to other enzymes indicates that negative cooperativity is a characteristic of many of them. These findings add strong support for the sequential model of subunit interactions which postulates that ligand-induced conformational changes are responsible for regulatory and cooperative phenomena in enzymes.