Mechanism of transfer of reduced nicotinamide adenine dinucleotide among dehydrogenases. Transfer rates and equilibria with enzyme-enzyme complexes.
Mechanism of transfer of reduced nicotinamide adenine dinucleotide among dehydrogenases. Transfer rates and equilibria with enzyme-enzyme complexes.
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还原型烟酰胺腺嘌呤二核苷酸在脱氢酶之间的转移机制。
DOI：
10.1021/bi00379a006
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发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Bernhard,SA
中科院分区：
文献类型：
--
作者：
Srivastava,DK;Bernhard,SA
D. K. Srivastava和S. A. Bernhard*俄勒冈大学分子生物学研究所，Eugene, Oregon 97403摘要：利用瞬时停流动力学技术研究了NADH在AB对脱氢酶之间的直接转移以及NADH与单个E-NADH络合物的解离。这种NADH的AB转移不需要辅酶在水溶液环境中进行中间解离[Srivastava， D. K., & Bernhard， S. A.(1985) Biochemistry 24, 623-628]，也确定了NADH在水溶液和A、B脱氢酶位点之间的平衡分布。在足够高但可实现的脱氢酶浓度下，结合NADH的转移速率和平衡分布实际上与过量的酶浓度无关；当E2浓度过高时，大量NADH与E，位点结合。这些结果进一步证实了早期关于Ea-NADH-Eb复合物优先形成的动力学论点，其中辅酶直接在位点之间转移。在不同的AB脱氢酶对中，辅酶从一个位点转移到另一个位点的单分子特异性速率几乎是不变的。配合物内辅酶分布的平衡常数基本一致。在高[E2]和[E2]>[EJ>[NADH]， E [-NADH-E2和，·-2实际上是唯一含有辅酶的物种。与配合物内几乎不变的单分子NADH转移速率相反，NADH从E-NADH解离到水溶液的单分子特异性是高度可变的。复合物内辅酶转移的特定速率可以大大大于或大大小于辅酶从E-NADH解离到水环境的速率。因此，AB对内的酶-酶相互作用调节辅酶转移的速率。
D. K. Srivastava and S. A. Bernhard* Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403 Received May 29, 1986; Revised Manuscript Received November 10, 1986 abstract: The direct transfer of NADH between AB pairs of dehydrogenases and also the dissociation of NADH from individual E-NADH complexes have been investigated by transient stopped-flow kinetic techniques. Such AB transfers of NADH occur without the intermediate dissociation of coenzyme into the aqueous solvent environment [Srivastava, D. K., & Bernhard, S. A.(1985) Biochemistry 24, 623-628], The equilibrium distributions of limiting NADH among aqueous solvent and A and B dehydrogenase sites have also been determined. At sufficiently high but realizable concentrations of dehydrogenases, both the transfer rate and the equilibrium distribution of bound NADH are virtually independent of the excessive enzyme concentrations; at excessive E2 concentration, substantial NADH is bound to the E, site. These results further substantiate earlier kinetic arguments for the preferential formation of an Ea-NADH-Eb complex, within which coenzyme is directly transferred between sites. The unimolecular specific rates of coenzyme transferfrom site to site are nearly invariant among different AB dehydrogenase pairs. The equilibrium constants for the distribution of coenzyme within the· complexes are near unity. At high [E2] and for [E2]>[EJ>[NADH], E [-NADH-E2 and,·-2 are virtually the only coenzymecontained species. In contrast to the nearly invariant unimolecular NADH transfer rates within· complexes, unimolecular specificrates of dissociation of NADH from E-NADH into aqueous solution are highly variable. The specific rate of coenzyme transfer within the· complex can be either substantially greater than or substantially less than the rate of coenzyme dissociation from E-NADH into the aqueous environment. Thus, enzyme-enzyme interactions within the AB pairs modulate the rate of coenzyme transfer.
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3.0 A 分辨率下龙虾 apo-D-甘油醛-3-磷酸脱氢酶的结构。
影响因子：
5.6
作者：
Murthy,MR;Garavito,RM;Johnson,JE;Rossmann,MG
通讯作者：
Rossmann,MG
还原型烟酰胺腺嘌呤二核苷酸在脱氢酶之间的转移机制。
影响因子：
2.9
作者：
Srivastava,DK;Bernhard,SA
通讯作者：
Bernhard,SA
脱氢还原型辅酶差异谱、分辨率及其与氢转移立体特异性的关系。
影响因子：
2.9
作者：
H. F. Fisher;D. L. Adija;D. G. Cross
通讯作者：
D. G. Cross
DOI：
10.1016/b978-0-12-152828-7.50003-2
发表时间：
1986
期刊：
Current topics in cellular regulation
影响因子：
--
作者：
Srivastava,DK;Bernhard,SA
通讯作者：
Bernhard,SA
影响因子：
56.9
作者：
SRIVASTAVA, DK;BERNHARD, SA
通讯作者：
BERNHARD, SA