Watt R M, Voss E W
J Biol Chem. 1979 Mar 10;254(5):1684-90.
Differential accessibility of liganded, high affinity rabbit anti-fluorescyl IgG antibody combining sites to the aqueous milieu has been investigated by solvent perturbation of the extrinsic fluorescence of bound fluorophore. Iodide, a dynamic quencher of fluorescein, was selected for use in these studies after examination of a number of water-soluble fluorescence quenchers. Quenching of antibody-bound fluorophore by iodide was measured with a number of liganded anti-fluorescyl IgG preparations, demonstrating partial solvent exposure of the fluorophore as well as heterogeneity of the high affinity antibody populations. Fluorescence quenching, lifetime, and absorption spectroscopy provided evidence that the antibody-bound fluorophore quenched by iodide interacted with it directly and that anomalous binding of the anion to the surface of the protein, resulting in ground state perturbations of the immunoglobulin, could not explain the observed results.
通过结合荧光团的外在荧光的溶剂扰动，研究了与配体结合的高亲和力兔抗荧光素IgG抗体结合位点对水相环境的差异可及性。在考察了多种水溶性荧光淬灭剂后，选择碘化物作为荧光素的动态淬灭剂用于这些研究。用多种与配体结合的抗荧光素IgG制剂测量了碘化物对抗体结合荧光团的淬灭作用，证明了荧光团的部分溶剂暴露以及高亲和力抗体群体的异质性。荧光淬灭、寿命和吸收光谱提供了证据，表明被碘化物淬灭的抗体结合荧光团与其直接相互作用，并且阴离子与蛋白质表面的异常结合导致免疫球蛋白基态扰动，无法解释观察到的结果。
