David M. Greenberg, Bui-Duy Tam, Eduard Jenny, Benjamin Payes
{"title":"Highly purified dihydrofolate reductase of calf thymus","authors":"David M. Greenberg, Bui-Duy Tam, Eduard Jenny, Benjamin Payes","doi":"10.1016/0926-6593(66)90035-X","DOIUrl":null,"url":null,"abstract":"<div><p>A procedure has been developed for the preparation of essentially pure dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NAD(P)<sup>+</sup> oxidoreductase, EC 1.5.1.3) from calf-thymus glands. The following criteria of purity were observed: The preparation exhibited only a single protein component by sedimentation ultracentrifugation, sedimentation equilibrium, sucrose gradient centrifugation, and Sephadex chromatography; with a mean mol. wt. of 33 500.</p><p>Electrophoresis on acrylamide gel showed only a single boundary. The pH-activity curve, relative substrate specificity, Michaelis constants of the substrates, and the SH character of the enzyme have been determined. Monovalent cations and Mg<sup>2+</sup> enhanced the enzyme activity. Other divalent cations and sulfhydryl reagents were inhibitory. No stimulation of enzyme activity could be obtained by organic mercurials or urea.</p></div>","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1966-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90035-X","citationCount":"22","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/092665936690035X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 22
Abstract
A procedure has been developed for the preparation of essentially pure dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NAD(P)+ oxidoreductase, EC 1.5.1.3) from calf-thymus glands. The following criteria of purity were observed: The preparation exhibited only a single protein component by sedimentation ultracentrifugation, sedimentation equilibrium, sucrose gradient centrifugation, and Sephadex chromatography; with a mean mol. wt. of 33 500.
Electrophoresis on acrylamide gel showed only a single boundary. The pH-activity curve, relative substrate specificity, Michaelis constants of the substrates, and the SH character of the enzyme have been determined. Monovalent cations and Mg2+ enhanced the enzyme activity. Other divalent cations and sulfhydryl reagents were inhibitory. No stimulation of enzyme activity could be obtained by organic mercurials or urea.