Lim J, Turner A J
Department of Biochemistry and Molecular Biology, University of Leeds, UK.
FEBS Lett. 1996 Mar 4;381(3):188-90. doi: 10.1016/0014-5793(96)00124-x.
Aminopeptidase P (AP-P), purified to homogeneity from porcine kidney membranes, was completely inactivated by treatment with 0.2 mM diethylpyrocarbonate (DEP) at pH 7.0. Treatment of the modified enzyme with 20 mM hydroxylamine resulted in recovery of AP-P activity. The differential absorption of native and modified AP-P at 240 mm showed that DEP modified two histidyl residues per mol of AP-P. The substrates, bradykinin(1-5) and Gly-Pro-Hyp, and also the inhibitor, apstatin, could protect against DEP inactivation. These results suggest that histidine residues are critical for AP-P activity.
从猪肾膜中纯化至同质的氨肽酶P（AP-P），在pH 7.0条件下用0.2 mM焦碳酸二乙酯（DEP）处理后完全失活。用20 mM羟胺处理修饰后的酶可使AP-P活性恢复。天然和修饰后的AP-P在240 nm处的差异吸收表明，DEP每摩尔AP-P修饰两个组氨酸残基。底物缓激肽（1-5）、甘氨酰-脯氨酰-羟脯氨酸以及抑制剂阿普他汀可防止DEP失活。这些结果表明组氨酸残基对AP-P活性至关重要。
