K+、Na+和Li+对人红细胞吡哆醛激酶催化活性影响的动力学研究。

Enzyme & protein Pub Date : 1996-01-01 DOI:10.1159/000468639
P Lainé-Cessac, P Allain
{"title":"K+、Na+和Li+对人红细胞吡哆醛激酶催化活性影响的动力学研究。","authors":"P Lainé-Cessac,&nbsp;P Allain","doi":"10.1159/000468639","DOIUrl":null,"url":null,"abstract":"<p><p>Kinetic studies were conducted to examine the effects of K+, Na+ and Li+ on human erythrocyte pyridoxal kinase (PK) activity. A dialyzed hemolysate served as the PK source. The substrates used were pyridoxal (PL) and ATP. Determination of the enzymatic activity was based on HPLC separation and fluorimetric detection of PL and pyridoxal 5'-phosphate as semicarbazone derivatives. In comparison to the poor activity of PK assayed without monovalent cation, all tested cations are activators. Among them, K+ is the most effective, improving both PK affinity for the substrates and maximal velocity. Na+ increases maximal velocity and PK affinity for ATP but decreases it for PL. Li+ is a poor activator which seems to modify the enzymatic mechanism from a random to an ordered sequential pattern with ATP bound before PL. Results suggest that K+ and Na+ bind to PK on the same site while Li+ binds on another site. This hypothesis and the mechanism of monovalent cation-PK interaction are compared to other well-known K(+)-activated enzymes.</p>","PeriodicalId":11854,"journal":{"name":"Enzyme & protein","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000468639","citationCount":"15","resultStr":"{\"title\":\"Kinetic studies of the effects of K+, Na+ and Li+ on the catalytic activity of human erythrocyte pyridoxal kinase.\",\"authors\":\"P Lainé-Cessac,&nbsp;P Allain\",\"doi\":\"10.1159/000468639\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Kinetic studies were conducted to examine the effects of K+, Na+ and Li+ on human erythrocyte pyridoxal kinase (PK) activity. A dialyzed hemolysate served as the PK source. The substrates used were pyridoxal (PL) and ATP. Determination of the enzymatic activity was based on HPLC separation and fluorimetric detection of PL and pyridoxal 5'-phosphate as semicarbazone derivatives. In comparison to the poor activity of PK assayed without monovalent cation, all tested cations are activators. Among them, K+ is the most effective, improving both PK affinity for the substrates and maximal velocity. Na+ increases maximal velocity and PK affinity for ATP but decreases it for PL. Li+ is a poor activator which seems to modify the enzymatic mechanism from a random to an ordered sequential pattern with ATP bound before PL. Results suggest that K+ and Na+ bind to PK on the same site while Li+ binds on another site. This hypothesis and the mechanism of monovalent cation-PK interaction are compared to other well-known K(+)-activated enzymes.</p>\",\"PeriodicalId\":11854,\"journal\":{\"name\":\"Enzyme & protein\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1996-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1159/000468639\",\"citationCount\":\"15\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Enzyme & protein\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1159/000468639\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Enzyme & protein","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1159/000468639","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 15

摘要

采用动力学方法研究了K+、Na+和Li+对人红细胞吡哆醛激酶(PK)活性的影响。透析的溶血作为PK源。底物为吡哆醛(PL)和ATP。采用高效液相色谱法分离和荧光法检测聚乳酸和5′-磷酸吡哆醛缩氨基脲衍生物的酶活性。与没有一价阳离子的PK活性差相比,所有测试的阳离子都是激活剂。其中,K+最有效,既提高了对底物的PK亲和力,又提高了最大速度。Na+增加了最大速度和对ATP的PK亲和力,但降低了对PL的PK亲和力。Li+是一种较差的激活剂,似乎将酶促机制从随机模式改变为有序顺序模式,ATP在PL之前结合。结果表明,K+和Na+结合在同一位点上,而Li+结合在另一个位点上。这一假设和单价阳离子- pk相互作用的机制与其他已知的K(+)活化酶进行了比较。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Kinetic studies of the effects of K+, Na+ and Li+ on the catalytic activity of human erythrocyte pyridoxal kinase.

Kinetic studies were conducted to examine the effects of K+, Na+ and Li+ on human erythrocyte pyridoxal kinase (PK) activity. A dialyzed hemolysate served as the PK source. The substrates used were pyridoxal (PL) and ATP. Determination of the enzymatic activity was based on HPLC separation and fluorimetric detection of PL and pyridoxal 5'-phosphate as semicarbazone derivatives. In comparison to the poor activity of PK assayed without monovalent cation, all tested cations are activators. Among them, K+ is the most effective, improving both PK affinity for the substrates and maximal velocity. Na+ increases maximal velocity and PK affinity for ATP but decreases it for PL. Li+ is a poor activator which seems to modify the enzymatic mechanism from a random to an ordered sequential pattern with ATP bound before PL. Results suggest that K+ and Na+ bind to PK on the same site while Li+ binds on another site. This hypothesis and the mechanism of monovalent cation-PK interaction are compared to other well-known K(+)-activated enzymes.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信