Acetylation of prostaglandin endoperoxide synthetase with acetylsalicylic acid.
Acetylation of prostaglandin endoperoxide synthetase with acetylsalicylic acid.
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用乙酰水杨酸乙酰化前列腺素内过氧化物合成酶。
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
D. van Dorp
中科院分区：
文献类型：
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作者：
F. J. van der Ouderaa;M. Buytenhek;D. Nugteren;D. van Dorp
孵育纯化的前列腺素内过氧化物合成酶从绵羊水泡腺与阿司匹林的结果在共价结合的乙酰基水杨酸的乙酰基的蛋白质。在此乙酰化过程中，环氧合酶活性丧失，但过氧化物酶活性不丧失。当每条多肽链上几乎有一个乙酰基结合时（Mr = 68 000），反应完成。用链霉蛋白酶水解[~ 3 H]乙酰蛋白，得到放射性N-乙酰丝氨酸。然而，最初，链中内部丝氨酸残基的羟基被乙酰化。N-乙酰丝氨酸的形成可以解释为，一旦丝氨酸的NH 2基团被释放，快速的O导致N乙酰基转移。从含有苯丙氨酸和丝氨酸的[3 H]乙酰酶的嗜热菌蛋白酶消化物中分离出放射性二肽，苯丙氨酸是其N-末端氨基酸。天然酶和乙酰化酶的自动Edman降解显示仅存在一个多肽序列：Ala-Asp-Pro-Gly-Ala-Pro-Ala-Pro-Val-Asn-Pro-X-X-Tyr-。N-末端序列具有非极性特征。
Incubation of purified prostaglandin endoperoxide synthetase from sheep vesicular glands with aspirin results in a covalent binding of the acetyl group of acetylsalicylic acid to the protein. During this acetylation, the cyclooxygenase activity is lost, but not the peroxidase activity. The reaction is completed when almost one acetyl group is bound per polypeptide chain (Mr = 68 000). After proteolysis of [3H]acetyl-protein with pronase, radioactive N-acetylserine was obtained. Originally, however, the hydroxyl group of an internal serine residue in the chain is acetylated. The formation of N-acetylserine can be explained by a rapid O leads to N acetyl shift as soon as the NH2 group of serine is liberated. A radioactive dipeptide was isolated from a thermolysin digest of the [3H]acetyl-enzyme containing phenylalanine and serine, phenylalanine being its N-terminal amino acid. Automatic Edman degradation of native and acetylated enzyme showed that only one polypeptide sequence was present: Ala-Asp-Pro-Gly-Ala-Pro-Ala-Pro-Val-Asn-Pro-X-X-Tyr-. The N-terminal sequence has an apolar character.