Suppr超能文献

新生大鼠胰岛中存在肽α-酰胺化活性的证据。

Evidence for presence of peptide alpha-amidating activity in pancreatic islets from newborn rats.

作者信息

Zhou A, Thorn N A

机构信息

Department of Medical Physiology C, University of Copenhagen, Denmark.

出版信息

Biochem J. 1990 Apr 1;267(1):253-6. doi: 10.1042/bj2670253.

Abstract

The peptide alpha-amidating activity of a homogenate of pancreatic islets from 5-7-day-old rats was investigated, using as substrate a glycine-extended tripeptide (D-Tyr-Val-Gly). The islet homogenates had a marked amidating activity, with a Km of 57 microM, a Vmax. of 185 pmol/h per mg and a pH optimum of 7.0. This activity was dependent on the presence of ascorbic acid (in the reduced form) and Cu2+, the optimum concentrations being 4 mM and 40 microM respectively. On fractionation of the homogenate, the highest specific activity was found in the soluble fraction. Exocrine pancreatic tissue showed very low levels of amidating activity.

摘要

利用甘氨酸延伸三肽(D-酪氨酸-缬氨酸-甘氨酸)作为底物,研究了5至7日龄大鼠胰岛匀浆的肽α-酰胺化活性。胰岛匀浆具有显著的酰胺化活性,Km为57微摩尔,Vmax为每毫克每小时185皮摩尔,最适pH为7.0。该活性依赖于抗坏血酸(还原形式)和Cu2+的存在,最适浓度分别为4毫摩尔和40微摩尔。对匀浆进行分级分离时,发现可溶性部分的比活性最高。胰腺外分泌组织的酰胺化活性水平非常低。

相似文献

本文引用的文献

5
Fluorometric assay of proteins in the nanogram range.纳克级蛋白质的荧光测定法。
Arch Biochem Biophys. 1973 Mar;155(1):213-20. doi: 10.1016/s0003-9861(73)80023-2.

文献检索

告别复杂PubMed语法,用中文像聊天一样搜索,搜遍4000万医学文献。AI智能推荐,让科研检索更轻松。

立即免费搜索

文件翻译

保留排版,准确专业,支持PDF/Word/PPT等文件格式,支持 12+语言互译。

免费翻译文档

深度研究

AI帮你快速写综述,25分钟生成高质量综述,智能提取关键信息,辅助科研写作。

立即免费体验