{"title":"Stability of lactate dehydrogenase","authors":"Joachim Müller, Cornelia Klein","doi":"10.1016/0005-2795(81)90091-X","DOIUrl":null,"url":null,"abstract":"<div><p>Hybrids of lactate dehydrogenases from pig heart and muscle and from chicken heart and pig heart were obtained by the freeze-thaw method [1,2]. Ion-exchange chromatography of the resulting mixtures of hybrids yielded unusual elution patterns, i.e., the 2 + 2 hybrids (H<sub>2</sub><sup>P</sup>M<sub>2</sub><sup>P</sup> and H<sub>2</sub><sup>C</sup>H<sub>2</sub><sup>P</sup>) were eluted in two separate peaks. These subforms were concluded to result from partial resolution of the three geometric isomers. The hybrids of chicken heart and pig heart lactate dehydrogenase showed three distinct levels of stability. The characteristic temperatures of denaturation were 61.5°C for H<sub>4</sub><sup>P</sup>, H<sup>C</sup>H<sub>3</sub><sup>P</sup> and H<sub>2</sub><sup>C</sup>H<sub>2</sub><sup>P</sup>I; 71°C for H<sub>2</sub><sup>C</sup>H<sub>2</sub><sup>P</sup>II and H<sub>3</sub><sup>C</sup>H<sup>P</sup> and 76.5°C for H<sub>4</sub><sup>C</sup>. The resistance towards thermal denaturation thus seemed to be governed by the least stable dimer within the tetrameric enzyme. The arrangement of stabilities of the dimers was in excellent agreement with the number of additional ion pairs between Arg<sub>241</sub> (chicken) and Asp<sub>57</sub> (chicken and pig) [3] within the Q-contact areas. The rate-determining step of thermal denaturation of lactate dehydrogenase was concluded to comprise the distortion or dissociation of one of two Q-contacts of the tetramer.</p></div>","PeriodicalId":100165,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure","volume":"671 1","pages":"Pages 38-43"},"PeriodicalIF":0.0000,"publicationDate":"1981-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0005-2795(81)90091-X","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biochimica et Biophysica Acta (BBA) - Protein Structure","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/000527958190091X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
Hybrids of lactate dehydrogenases from pig heart and muscle and from chicken heart and pig heart were obtained by the freeze-thaw method [1,2]. Ion-exchange chromatography of the resulting mixtures of hybrids yielded unusual elution patterns, i.e., the 2 + 2 hybrids (H2PM2P and H2CH2P) were eluted in two separate peaks. These subforms were concluded to result from partial resolution of the three geometric isomers. The hybrids of chicken heart and pig heart lactate dehydrogenase showed three distinct levels of stability. The characteristic temperatures of denaturation were 61.5°C for H4P, HCH3P and H2CH2PI; 71°C for H2CH2PII and H3CHP and 76.5°C for H4C. The resistance towards thermal denaturation thus seemed to be governed by the least stable dimer within the tetrameric enzyme. The arrangement of stabilities of the dimers was in excellent agreement with the number of additional ion pairs between Arg241 (chicken) and Asp57 (chicken and pig) [3] within the Q-contact areas. The rate-determining step of thermal denaturation of lactate dehydrogenase was concluded to comprise the distortion or dissociation of one of two Q-contacts of the tetramer.