人胎盘和妊娠血清中精氨酸加压素降解的起始和负责酶。

Initiating and responsible enzyme of arginine vasopressin degradation in human placenta and pregnancy serum.

作者信息

Mizutani S, Safwat M A, Goto K, Tsujimoto M, Nakazato H, Itakura A, Mizuno M, Kurauchi O, Kikkawa F, Tomoda Y

机构信息

Department of Obstetrics and Gynecology, Nagoya University School of medicine, Japan.

出版信息

Regul Pept. 1995 Nov 10;59(3):371-8. doi: 10.1016/0167-0115(95)00108-n.

DOI:10.1016/0167-0115(95)00108-n

PMID:8577942

Abstract

The hydrolysis of arginine vasopressin (AVP) by human placental subcellular fractions and pregnancy sera was studied in the presence of selective inhibitors and the antibody against pregnancy serum oxytocinase (P-LAP) (EC 3.4.11.3) by measuring liberated amino acids by high-performance liquid chromatography (HPLC). AVP degradation by placental subcellular fractions and pregnancy sera was inhibited by bestatin. The IC50 values of bestatin on AVP degradation by placental subcellular fractions and pregnancy sera were similar to that of this inhibitor on the P-LAP measured by L-Leu-p-nitroamnilide as a substrate (LAP activity), which we reported previously. Our immunotitration study clearly showed that the initiating and responsible protease in AVP degradation in human placenta and pregnancy serum is P-LAP. Since N-benzylcarbonyl-valyl-prolinal (Z-Val-prolinal), a selective inhibitor of post-proline endopeptidase, and phosphoramidon, a putative endopeptidase-24.11 inhibitor, could not significantly influence the degradation of AVP by placental microsomal fractions. Neither enzyme seems to be actively involved in AVP degradation.

摘要

通过高效液相色谱法（HPLC）测定游离氨基酸，研究了在选择性抑制剂和抗妊娠血清催产素酶（P-LAP，EC 3.4.11.3）抗体存在的情况下，人胎盘亚细胞组分和妊娠血清对精氨酸加压素（AVP）的水解作用。贝司他汀抑制了胎盘亚细胞组分和妊娠血清对AVP的降解。贝司他汀对胎盘亚细胞组分和妊娠血清降解AVP的IC50值，与我们之前报道的以L-亮氨酸对硝基苯胺为底物（LAP活性）测定该抑制剂对P-LAP的IC50值相似。我们的免疫滴定研究清楚地表明，人胎盘和妊娠血清中AVP降解的起始和主要蛋白酶是P-LAP。由于脯氨酸后内切酶的选择性抑制剂N-苄羰基-缬氨酰-脯氨醛（Z-Val-prolinal）和假定的内肽酶-24.11抑制剂磷酰胺素，对胎盘微粒体组分降解AVP没有显著影响。这两种酶似乎都没有积极参与AVP的降解。