Enzymatic studies on ascorbic acid catabolism in animals. II. Delactonization of dehydro-L-ascorbic acid.
Enzymatic studies on ascorbic acid catabolism in animals. II. Delactonization of dehydro-L-ascorbic acid.
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动物抗坏血酸分解代谢的酶学研究。
DOI：
10.1093/oxfordjournals.jbchem.a127521
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发表时间：
1962
影响因子：
2.7
通讯作者：
H. Takiguchi
中科院分区：
文献类型：
--
作者：
Y. Kagawa;H. Takiguchi
在实验条件下描述了动物组织中脱氢- l -抗坏血酸的酶解脱乙酰化过程，在pH值为生理范围的条件下，所产生的双酮gulonic酸没有损失。酶被纯化，性质包括反应时间和酶浓度的比例，辅因子的需求，化学计量学，抑制剂，和没有逆反应描述。反应产物为2,3-二酮- l -谷兰酸。该酶与内酯酶I（醛醛酸内酯酶）几乎具有相同的性质，并且在酶纯化过程中除去了酯酶和内酯酶II（脲醛酸内酯酶），但它们之间没有相互分离。讨论了该酶在抗坏血酸不可逆分解代谢过程中的作用，以及在灵长类动物中由于缺乏其活性而引起的生理发现。
The enzymatic delactonization of de hydro-L-ascorbic acid in animal tissue was described with the assay condition without loss of resulting diketogulonic acid at pH of the physiological range.The enzyme was purified, and properties including proportionality of the reaction to time and enzyme concentration, cofactor requirement, stoichiometry, inhibitors, and the absence of the reverse reaction were described. The reaction product was confirmed as 2,3-diketo-L-gulonic acid.The enzyme was possibly identical to lactonase I (aldonolactonase) in almost all the properties tested and they were not separated from each other though esterases and lactonase II (uronolactonase) were removed in the course of enzyme purification.The role of this enzyme in this irreversible process of ascorbic acid catabolism and physiological findings caused by the lack of its activity in primates were discussed.