{"title":"Interaction of antibiotic lasalocid A (X537A) with praseodymium(III) in methanol","authors":"Shuenn-tzong Chen, Charles S. Springer Jr.","doi":"10.1016/S0006-3061(00)80284-7","DOIUrl":null,"url":null,"abstract":"<div><p>The binding of lasalocid A (X537A) to Pr(III) in methanol has been studied by lasalocid fluorescence, circular dichtoism, and <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy. It is clear that in addition to a mono complex, bis and tris complexes are also formed. Values of the binding constants and spectral properties of the various complexes have been determined by computer fitting of the binding isotherms. The Pr(III) ion binds only at the salicylic “head” of the lasalocid A, in stark contrast with other known structures. The lasalocid A appears to have an “open” conformation in these complexes. The relevance of these results to the structure and conformation of the Ca(II) complex is discussed. The first order rate constant for the dissociation of the tris complex has also been determined.</p></div>","PeriodicalId":9177,"journal":{"name":"Bioinorganic chemistry","volume":"9 2","pages":"Pages 101-122"},"PeriodicalIF":0.0000,"publicationDate":"1978-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0006-3061(00)80284-7","citationCount":"14","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bioinorganic chemistry","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0006306100802847","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 14
Abstract
The binding of lasalocid A (X537A) to Pr(III) in methanol has been studied by lasalocid fluorescence, circular dichtoism, and 1H and 13C NMR spectroscopy. It is clear that in addition to a mono complex, bis and tris complexes are also formed. Values of the binding constants and spectral properties of the various complexes have been determined by computer fitting of the binding isotherms. The Pr(III) ion binds only at the salicylic “head” of the lasalocid A, in stark contrast with other known structures. The lasalocid A appears to have an “open” conformation in these complexes. The relevance of these results to the structure and conformation of the Ca(II) complex is discussed. The first order rate constant for the dissociation of the tris complex has also been determined.
用lasalocid荧光、圆二分体、1H和13C NMR研究了lasalocid A (X537A)在甲醇中与Pr(III)的结合。很明显,除了单络合物外,还形成了双和三络合物。通过计算机拟合结合等温线,确定了各种配合物的结合常数和光谱性质。Pr(III)离子仅结合在lasalocid A的水杨酸“头部”,与其他已知结构形成鲜明对比。喇沙酸A在这些复合物中似乎具有“开放”构象。讨论了这些结果与Ca(II)配合物的结构和构象的相关性。还确定了三络合物解离的一级速率常数。