CHIRAL SEPARATION MECHANISMS IN PROTEIN-BASED HPLC COLUMNS .1. THERMODYNAMIC STUDIES OF (R)-WARFARIN AND (S)-WARFARIN BINDING TO IMMOBILIZED HUMAN SERUM-ALBUMIN
CHIRAL SEPARATION MECHANISMS IN PROTEIN-BASED HPLC COLUMNS .1. THERMODYNAMIC STUDIES OF (R)-WARFARIN AND (S)-WARFARIN BINDING TO IMMOBILIZED HUMAN SERUM-ALBUMIN
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DOI：
10.1021/ac00093a043
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发表时间：
1994-11-01
影响因子：
7.4
通讯作者：
HAGE, DS
中科院分区：
文献类型：
--
作者：
LOUN, B;HAGE, DS
本文研究了在高效人血清白蛋白（HSA）柱上（R）-和（S）-华法林结合和分离的热力学过程。前沿分析用于确定每种对映异构体的结合强度和程度。(R)-和（S）-华法林结合在HSA上的相同区域;然而，（R）-华法林具有更多的柱结合位点。两种对映异构体的结合位点的数量随温度略有增加。在37 ℃下，（R）和（S）-华法林结合的自由能总变化相似，但R-对映体的熵贡献更大。这些结果表明，（R）-华法林主要与结合位点内部相互作用，而（S）-华法林更多地与结合位点的外表面相互作用。通过检查在各种pH、离子强度和有机改性剂条件下HSA柱上（R）-和（S）-华法林的保留来证实该模型。这些溶质的熵的不同变化使得可以通过改变柱温来改变它们的分离。热力学性质和柱结合能力被认为是重要的，在确定这些化合物的分离程度。
This work characterizes the thermodynamic processes involved in the binding and separation of (R)- and (S)-warfarin on a high-performance human serum albumin (HSA) column. Frontal analysis was used to determine the strength and degree of binding for each enantiomer. (R)- and (S)-warfarin were found to bind at the same region on HSA; however, (R)-warfarin had a larger number of column binding sites. The number of binding sites for both enantiomers showed a slight increase with temperature. The total changes in free energy for (R)and (S)-warfarin binding were similar at 37 degrees C, but the contribution due to entropy was greater for the R-enantiomer. These results suggested that (R)-warfarin was interacting mainly with the binding site interior, while (S)-warfarin interacted more with the site's outer surface. This model was confirmed by examining the retention of (R)- and (S)-warfarin on the HSA column under various pH, ionic strength, and organic modifier conditions. The different changes in entropy for these solutes made it possible to vary their separation by changing column temperature. Both thermodynamic properties and column binding capacities were found to be important in determining the degree of separation obtained for these compounds.