Binding properties of a monoclonal antibody directed toward lead-chelate complexes
Binding properties of a monoclonal antibody directed toward lead-chelate complexes
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DOI：
10.1021/bc9901548
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发表时间：
2000-03-01
影响因子：
4.7
通讯作者：
Blake, RC
中科院分区：
文献类型：
--
作者：
Khosraviani, M;Blake, RC
一种单克隆抗体（2C 12），识别Pb（II）-环己基二亚乙基三胺五乙酸络合物的BALB/c小鼠注射与Pb（II）-螯合物共价偶联到载体蛋白。通过测量平衡解离常数评估纯化抗体与各种无金属螯合剂和金属螯合复合物相互作用的能力。抗体与无金属反式环己基二亚乙基三胺五乙酸（CHXDTPA）结合，平衡解离常数为2.3 x 10（-7）M。添加Pb（II）使抗体对复合物的亲和力增加了25倍; Pb（II）是唯一的金属。阳离子（测试的15种不同的二价、三价和六价金属），其增加抗体对CHXDTPA的亲和力。亲和力的增加主要是由于缔合速率常数的增加。该抗体也有能力与乙二胺四乙酸（EDTA），二亚乙基三胺五乙酸（DTPA），和结构上相关的衍生物，但从50- 10000倍的亲和力比CHXDTPA确定的。向EDTA基螯合剂中添加金属降低了抗体对这些配体的亲和力。然而，当DTPA用作螯合剂时，添加Pb（IT）使抗体对复合物的亲和力增加200倍。原型免疫测定的灵敏度Pb（II）可以调制通过改变固定的金属螯合物的复合物和/或可溶性螯合剂的结构用于复杂的Pb（II）在测试溶液中。
A monoclonal antibody (2C12) that recognizes a Pb(II)-cyclohexyldiethylenetriamine pentaacetic acid complex was produced by the injection of BALB/c mice with a Pb(II)-chelate complex covalently coupled to a carrier protein. The ability of purified antibody to interact with a variety of metal-free chelators and metal-chelate complexes was assessed by measuring equilibrium dissociation constants. The antibody bound to metal-free trans-cyclohexyldiethylenetriamine pentaacetic acid (CHXDTPA) with an equilibrium dissociation constant of 2.3 x 10(-7) M. Addition of Pb(II) increased the affinity of the antibody for the complex by 25-fold; Pb(II) was the only metal. cation (of 15 different di-, tri-, and hexavalent metals tested) that increased the affinity of the antibody for CHXDTPA. The increased affinity was due primarily to an increase in the association rate constant. The antibody also had the ability to interact with ethylenediamine tetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DTPA), and structurally related derivatives, but with affinities from 50- to 10000-fold less than that determined for CHXDTPA. Addition of metals to EDTA-based chelators reduced the affinity of the antibody for these ligands. However, when DTPA was used as the chelator, addition of Pb(IT) increased the affinity of the antibody for the complex by 200-fold. The sensitivity of prototype immunoassays for Pb(II) could be modulated by changing the structure of the immobilized metal-chelate complex and/or the soluble chelator used to complex Pb(II) in the test solution.