ENZYMATIC BREAKDOWN OF PANTETHINE TO PANTOTHENIC ACID AND CYSTAMINE
ENZYMATIC BREAKDOWN OF PANTETHINE TO PANTOTHENIC ACID AND CYSTAMINE
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DOI：
10.1111/j.1432-1033.1970.tb01119.x
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发表时间：
1970-01-01
期刊：
影响因子：
--
通讯作者：
DELGROSS.E
中科院分区：
文献类型：
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作者：
DUPRE, S;GRAZIANI, MT;DELGROSS.E
从马肾开始，将泛氨酸分解为泛酸和半胱胺的酶已纯化了约3000次。报道了其提纯过程。该酶的最适活性范围在4.0-5.5之间，需要还原的硫醇才能发挥全部活性：硫醇和二硫苏糖醇的效果更好。这种激活似乎不是特定的。该酶对底物的Km值约为5 mM，并受到过量底物和副产物的抑制。底物专一性研究表明，该酶只裂解完整的底物分子，不被几种水解酶水解，即使具有广泛的专一性(如细菌链霉蛋白酶和枯草杆菌蛋白酶)。该酶可能负责体内半胱胺的产生，已知半胱胺是由本实验室最近分离的一种特定加氧酶氧化的。
The enzyme splitting pantethine into pantothenic acid and cystamine has been purified about 3000 times starting from horse kidney. The purification procedure is reported. The enzyme, whose optimal activity lies in the pH range 4.0–5.5, requires the presence of a reduced thiol for the full activity: mercaptoethanol and dithiothreitol give the higher effect. This activation seems not to be specific. The enzyme has aKmvalue for the substrate of the order of 5 mM and shows inhibition by excess substrate and by products. Substrate specificity studies show that the enzyme splits only the intact substrate molecule, which is not hydrolyzed by several hydrolytic enzymes, even with a broad specificity (as bacterial pronase and subtilisin). The enzyme could be responsible for the productionin vivoof cysteamine, which is known to be oxydized by a specific oxygenase, isolated recently in this laboratory.