STUDIES ON PROPHOSPHOLIPASE A2 AND ITS ENZYME FROM HUMAN PANCREATIC-JUICE - CATALYTIC PROPERTIES AND SEQUENCE OF THE N-TERMINAL REGION
STUDIES ON PROPHOSPHOLIPASE A2 AND ITS ENZYME FROM HUMAN PANCREATIC-JUICE - CATALYTIC PROPERTIES AND SEQUENCE OF THE N-TERMINAL REGION
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DOI：
10.1111/j.1432-1033.1982.tb05855.x
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
FIGARELLA, C
中科院分区：
文献类型：
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作者：
GRATAROLI, R;DIJKMAN, R;FIGARELLA, C
在胰蛋白酶活化纯的人磷脂酶A2原后，从蛋白质的N-末端部分释放七肽，产生活性磷脂酶A2（EC 3.1.1.4）。活化过程的动力学和活化肽的氨基酸序列与其他哺乳动物来源的胰腺酶原非常相似。人磷脂酶A2及其酶原的动力学性质进行了比较与相应的猪酶使用基板存在的胶束，分子分散的解决方案或作为单分子表面膜。人和猪磷脂酶A2之间最明显的差异是前者蛋白质在pH 8.0下对胶束和单体底物的酶活性低于pH 6.0。无论是Ca 2+的结合特性，也不是抑制动力学的人类酶使用卤代酮可以很容易地解释这种不同的pH值的最佳。报告了前40个残基的N-末端区域的序列分析。
Upon tryptic activation of pure human prophospholipase A2, a heptapeptide is released from the N-terminal part of the protein yielding active phospholipase A2 (EC 3.1.1.4). The kinetics of the activation process and the amino acid sequence of the activation peptide strongly resemble those of pancreatic zymogens of other mammalian sources. The kinetic properties of human phospholipase A2 and its zymogen are compared with those of the corresponding porcine enzyme using substrates present as micelles, molecular dispersed solutions or as monomolecular surface films. The most obvious difference between the human and porcine phospholipase A2 is the low enzyme activity of the former protein at pH 8.0 as compared to pH 6.0, against micellar and monomeric substrates. Neither the Ca2+ binding properties nor the inhibition kinetics of the human enzyme using haloketones can easily explain this different pH optimum. The sequence analysis of the N-terminal region of the first 40 residues is reported.