{"title":"Evidence for binding of NAD dimers to NAD-dependent dehydrogenases","authors":"Alessandro Finazzi-Agrò , Luciana Avigliano , Vincenzo Carelli , Felice Liberatore , Antonio Casini","doi":"10.1016/0005-2744(81)90090-5","DOIUrl":null,"url":null,"abstract":"<div><p>The binding of dimers of nicotinamide adenine dinucleotide, (NAD)<sub>2</sub>, to lactate, malate and alcohol dehydrogenase has been studied by the fluorescence quenching technique. While the alcohol dehydrogenase shows a low binding ability, malate and lactate dehydrogenases have been found to bind (NAD)<sub>2</sub> in a specific way with high affinity. Malate dehydrogenase binds (NAD)<sub>2</sub> more than NADH. All three dehydrogenases are inhibited by (NAD)<sub>2</sub>, which behaves as a competitive inhibitor with respect to both NAD<sup>+</sup> and NADH. These results show that (NAD)<sub>2</sub> is bound to the nucleotide-specific binding site of the dehydrogenases. (NAD)<sub>2</sub> was found to stoichiometrically react with ferricyanide at variance with NADH. The specific interactions with the NAD-dependent dehydrogenases and the ability to enter in monoelectronic redox cycles suggest possible physiological roles for (NAD)<sub>2</sub>.</p></div>","PeriodicalId":100159,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology","volume":"661 1","pages":"Pages 120-123"},"PeriodicalIF":0.0000,"publicationDate":"1981-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0005-2744(81)90090-5","citationCount":"11","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biochimica et Biophysica Acta (BBA) - Enzymology","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0005274481900905","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 11
Abstract
The binding of dimers of nicotinamide adenine dinucleotide, (NAD)2, to lactate, malate and alcohol dehydrogenase has been studied by the fluorescence quenching technique. While the alcohol dehydrogenase shows a low binding ability, malate and lactate dehydrogenases have been found to bind (NAD)2 in a specific way with high affinity. Malate dehydrogenase binds (NAD)2 more than NADH. All three dehydrogenases are inhibited by (NAD)2, which behaves as a competitive inhibitor with respect to both NAD+ and NADH. These results show that (NAD)2 is bound to the nucleotide-specific binding site of the dehydrogenases. (NAD)2 was found to stoichiometrically react with ferricyanide at variance with NADH. The specific interactions with the NAD-dependent dehydrogenases and the ability to enter in monoelectronic redox cycles suggest possible physiological roles for (NAD)2.