Electrostatic Effects in the Combination of Cobalt with Amino Acids1,2
Electrostatic Effects in the Combination of Cobalt with Amino Acids1,2
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钴与氨基酸结合的静电效应1,2
DOI：
10.1021/ja01100a017
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发表时间：
1953
影响因子：
15
通讯作者：
W. S. Shore
中科院分区：
文献类型：
--
作者：
C. Tanford;W. S. Shore
用Bjerrum法测定了钴与甘氨酸、丙氨酸、天冬酰胺和精氨酸的络合常数。精氨酸和丙氨酸的结果之间的差异可以成功地处理的Kirkwood-Westheimer理论的基础上，精氨酸的正电荷胍基团的静电影响。天冬酰胺的数据不能用这种方法来解释，并表明该分子中螯合基团（HzN-COO ~-）的结构是异常的。甘氨酸和丙氨酸的缔合常数之间存在明显的差异，对此没有明显的解释，许多研究比较了有关物质对氢离子的亲和力。已经发现，大多数的结果可以令人满意地解释柯克伍德-Westheimer理论3涉及带电或偶极取代基和反应质子之间的静电相互作用。本文尝试将这种处理方法推广到四种氨基酸，它们都含有H_2N-COO ~-螯合基团。
The association constants for complexing of cobalt with glycine, alanine, asparagine and arginine havebeen obtained from glass electrode measurements by Bjerrum’s method. The differencebetween the results for arginine and alanine can be successfully treated by the Kirkwood-Westheimer theory on the basis of the electrostatic influence of the positively-charged guanidine group of arginine. The data for asparaginecannot be explained in this way, and indicate that the structure of the chelating group (HzN-CHR-COO~) in this molecule is abnormal. There is an appreciable difference between the association constants for glycine and those for alanine, for which no obvious explanation exists.Numerous studies havebeen made comparing the affinity of related substances for hydrogen ion. It has been found that the majority of the results can be satisfactorily explained by the Kirkwood-Westheimer theory3 involving electrostatic inter-action between charged or dipolar substituents and the reacting proton. In the present paper an attempt is made to extendthis treatment to the affinity of four amino-acids, all containing the chelating group H2N-CHR-COO~ for cobaltous ion.