Evidence of heterogeneous 1-anilinonaphthalene-8-sulfonate binding to β-lactoglobulin from fluorescence spectroscopy
Evidence of heterogeneous 1-anilinonaphthalene-8-sulfonate binding to β-lactoglobulin from fluorescence spectroscopy
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DOI：
10.1016/s0167-4838(99)00105-3
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发表时间：
1999-07-13
期刊：
影响因子：
--
通讯作者：
Baldini, G
中科院分区：
文献类型：
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作者：
D'Alfonso, L;Collini, M;Baldini, G
稳态和动态荧光滴定表明：-（a）β-乳球蛋白（BLG）和1-苯胺基萘-8-磺酸盐（ANS）之间的复合物显示出结合强度随pH和离子浓度变化较大的非均相平衡;和（B）结合ANS的荧光响应揭示了两个独立的寿命，表明两个不同的位点（或结合模式）。虽然稳态荧光滴定产生的结合常数和绑定ANS量子效率的有效值，它示出，通过结合稳态荧光和寿命衰减的ANS，它是可能的，给出定量估计的关联常数为每个站点。当从酸（pH类似于2）到天然状态（pH类似于6）时，主要结果是有效结合常数的非常大的降低。这一点和滴定与离子强度的结果表明，静电相互作用。对ANS与BLG结合的主要贡献。(C)1999 Elsevier Science B. V.保留所有权利。
Steady-state and dynamic fluorescence titrations show that:-(a) the complex between beta-lactoglobulin (BLG) and 1-anilinonaphthalene-8-sulfonate (ANS) displays a heterogeneous equilibrium with large changes in the binding strength vs. pH and ion concentration; and (b) the fluorescence response of bound ANS reveals two separate lifetimes that suggest two different sites (or binding modes). While steady-state fluorescence titrations yield effective values of the binding constant and of the bound ANS quantum efficiency, it is shown that, by combining steady-state fluorescence and lifetime decay of ANS, it is possible to give quantitative estimates of the association constants for each site. When heading from the acid (pH similar to 2) to the native state (pH similar to 6) the main result is a very large reduction of the effective binding constant. This and the results of titrations vs. ionic strength suggest that electrostatic interactions are. a major contribution to ANS binding to BLG. (C) 1999 Elsevier Science B.V. All rights reserved.