A trivalent system from vancomycin•D-Ala-D-Ala with higher affinity than avidin•biotin
A trivalent system from vancomycin•D-Ala-D-Ala with higher affinity than avidin•biotin
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DOI：
10.1126/science.280.5364.708
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发表时间：
1998-05-01
期刊：
影响因子：
56.9
通讯作者：
Whitesides, GM
中科院分区：
文献类型：
--
作者：
Rao, JH;Lahiri, J;Whitesides, GM
Tris（万古霉素carboxamide）与D-Ala-D-Ala衍生的三价配体具有非常高的亲和力：解离常数（K-d）接近4 × 10(-17) +/- 1 × 10(-17) M.高亲和力的三价结合与单价结合有着根本的不同。在三价（更普遍的是，多价）结合中，解离是分阶段发生的，在足够高的浓度下，单价配体可以加速解离的速度。在单价结合中，解离仅由解离的速率常数决定，不能通过添加单体来加速解离。三价体系的量热测量表明，相对于相应的单体，焓近似增加。该系统是已知的涉及小分子的最稳定的有机受体-配体对之一。它说明了设计基于多价的高亲和体系的实用性。
Tris(vancomycin carboxamide) binds a trivalent ligand derived from D-Ala-D-Ala with very high affinity: dissociation constant (K-d) approximate to 4 x 10(-17) +/- 1 x 10(-17) M. High-affinity trivalent binding and monovalent binding are fundamentally different. In trivalent (and more generally, polyvalent) binding, dissociation occurs in stages, and its rate can be accelerated by monovalent ligand at sufficiently high concentrations. In monovalent binding, dissociation is determined solely by the rate constant for dissociation and cannot be accelerated by added monomer. Calorimetric measurements for the trivalent system indicate an approximately additive gain in enthalpy relative to the corresponding monomers. This system is one of the most stable organic receptor-ligand pairs involving small molecules that is known. It illustrates the practicality of designing very high-affinity systems based on polyvalency.