关于人类尿芳基酰胺酶的研究。

Studies on human urinary arylamidases.

作者信息

Raina P N, Ellis S

出版信息

Arch Int Physiol Biochim. 1975 Aug;83(3):519-28. doi: 10.3109/13813457509071396.

Abstract

Human urinary protein was found to contain enzymes that hydrolyze leucyl-, alanyl-, and glycyl-prolyl-beta-naphthylamides. The kinetic constants of these enzymes were determined and their chemical properties studied. The values for Km calculated for leucyl-, alanyl-, and glycyl-prolyl arylamidases were 3.7 times 10(-5) M, 7.1 times 10(-5) M, and 1 times 10(-4) M, respectively. The pH optima for the hydrolysis of Leu-beta-naphthylamide and Ala-beta-naphthylamide were between 7.4-7.8; whereas for glycyl-prolyl-beta-naphthylamide, it was around 8.8. Unlike the glycyl-prolyl-arylamidase which was inhibited by Co2+ and Mn2+, the other two arylamidases were slightly activated by Co2+. p-Chloromercuriphenyl-sulfonate and puromycin significantly inhibited leucyl-, and alanyl arylamidases. The mean values for 24-h urinary output for leucyl-, alanyl-, and glycyl-prolyl arylamidases in normal human male subjects were 4.32, 9.97, and 2.2 units, respectively.

摘要

人们发现人尿蛋白中含有能水解亮氨酰 -、丙氨酰 - 和甘氨酰 - 脯氨酰 -β- 萘酰胺的酶。测定了这些酶的动力学常数并研究了它们的化学性质。亮氨酰 -、丙氨酰 - 和甘氨酰 - 脯氨酰芳基酰胺酶的 Km 值分别为 3.7×10⁻⁵ M、7.1×10⁻⁵ M 和 1×10⁻⁴ M。水解亮氨酰 -β- 萘酰胺和丙氨酰 -β- 萘酰胺的最适 pH 在 7.4 - 7.8 之间；而对于甘氨酰 - 脯氨酰 -β- 萘酰胺，最适 pH 约为 8.8。与受 Co²⁺ 和 Mn²⁺ 抑制的甘氨酰 - 脯氨酰芳基酰胺酶不同，其他两种芳基酰胺酶受 Co²⁺ 轻微激活。对氯汞苯磺酸盐和嘌呤霉素显著抑制亮氨酰 - 和丙氨酰芳基酰胺酶。正常男性受试者尿中亮氨酰 -、丙氨酰 - 和甘氨酰 - 脯氨酰芳基酰胺酶 24 小时排出量的平均值分别为 4.32、9.97 和 2.2 单位。