OXALYL-COENZYME A SYNTHETASE FROM PEA SEEDS
OXALYL-COENZYME A SYNTHETASE FROM PEA SEEDS
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DOI：
10.1016/s0926-6593(66)80151-0
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发表时间：
1966-01-01
期刊：
影响因子：
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通讯作者：
GIOVANELLI, J
中科院分区：
文献类型：
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作者：
GIOVANELLI, J
催化反应的新酶：草酸盐+腺苷5[图片] -三磷酸+辅酶A [图片]草酰-辅酶A+腺苷5[图片]-磷酸+无机焦磷酸已从豌豆种子提取物中部分纯化。在羽扇豆和南瓜的种子以及小麦胚芽中也证实了这一点。通过草酰羟酸的形成速率、辅酶A的酯化速率或无机[p32]焦磷酸与腺苷5[image]-三磷酸的交换速率来测定酶。反应的化学计量通过证明：（a）腺苷5[image]-磷酸的产生;（B）羟肟酸测定中草酰羟肟酸和无机焦磷酸的化学计量形成;（c）无机[p32]焦磷酸（但不是无机[p32]磷酸）与腺苷5[image] -三磷酸之间的交换。辅酶A浓度的增加引起了这种交换的进行性抑制。无机[p32]焦磷酸交换数据与通过草酰化中间体进行的反应一致。酶的一般性质进行了描述，和可能的生化功能的酶和草酰辅酶A进行了讨论。
A new enzyme which catalyzes the reaction: Oxalate + adenosine 5[image] -triphosphate + coenzyme A [image] Oxalyl-coenzyme A+ adenosine 5[image]-phosphate + inorganic pyrophosphate has been partially purified from extracts of pea seeds. It was also demonstrated in seeds of lupine and pumpkin, and in wheat germ. The enzyme was assayed either by the rate of formation of oxalylhydroxa-mate, by the rate of esterification of coenzyme A, or by the rate of exchange of inorganic [p32]pyrophosphate with adenosine 5[image]-triphosphate. The stoichiometry of the reaction was determined by demonstrating: (a) the production of adenosine 5[image]-phosphate; (b) the stoichiometric formation of oxalylhydroxamate and inorganic pyrophosphate in the hydroxa-mate assay; (c) the exchange between inorganic [p32]pyrophosphate, but not of inorganic [p32]phosphate, and adenosine 5[image] -triphosphate. Increasing concentrations of coenzyme A caused a progressive inhibition of this exchange. The inorganic [p32]pyrophosphate exchange data are consistent with the reaction proceeding via an oxalyladenylate intermediate. The general properties of the enzyme are described, and the possible biochemical function of the enzyme and of oxalyl-coenzyme A is discussed.