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摘要: 采用荧光光谱法和紫外光谱法研究了5种二价金属离子与牛血清白蛋白(BSA)的相互作用,通过生物大分子猝灭反应机制和结合位点模型研究发现锌离子Zn2+,镍离子Ni2+,钴离子Co2+ 和钙离子Ca2+ 均可导致牛血清白蛋白内源荧光猝灭,Zn2+,Ni2+ 和Co2+ 离子半径处在正常范围,能有效进入牛血清白蛋白结合位点与牛血清白蛋白结合形成超分子配合物,使牛血清白蛋白的二级结构发生改变,主要表现为静态猝灭。Ca2+离子半径较大,受空间位阻影响不能有效进入结合位点对BSA二级结构影响较小,不能与BSA形成配合物,表现为动态猝灭;而Mg2+ 由于大的水合半径阻碍了Mg2+ 与牛血清白蛋白的有效碰撞,使电子或能量的转移受阻,从而导致Mg2+ 对牛血清白蛋白内源荧光无猝灭作用。图3表2参16
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关键词:
- 动物学 /
- 金属离子(Ⅱ) /
- 牛血清白蛋白(BSA) /
- 荧光光谱 /
- 紫外光谱
Abstract: To obtain the principal of the interactions among bovine serum albumins(BSA)and the bivalent metal ions,the interactions of five bivalent metal ions(Zn2+,Ni2+,Co2+,Ca2+,and Mg2+),and BSA were studied using fluorescence spectroscopy and ultraviolet spectroscopy. Also, a quenching reaction mechanism of biomacromolecules was used with the site binding model, and quenching of the intrinsic fluorescence of BSA was found by adding Zn2+,Ni2+,Co2+,and Ca2+. For the appropriate ionic radius of Zn2+,Ni2+,and Co2+,a supramolecular complex was formed among the metal ions and BSA by effectively entering the binding site of the BSA. At the same time,the secondary structure of BSA was changed and manifested as static quenching. But the supramolecular complex could not be formed between BSA and Ca2+ for the influence of the steric hindrance due to a greater ionic radius of Ca2+. Additionally,since the metal ion Mg2+ had a much greater hydrated radius than the other divalent ions, an effective collision between Mg2+ and BSA was prevented. Therefore, the metal ion Ca2+ was only manifested as dynamic quenching, and metal ion Mg2+ had no quenching effect on the intrinsic fluorescence of BSA. Ca2+,Mg2+ other than the ions Zn2+, Ni2+,and Co2+,had no interactions with BSA.[Ch,3 fig. 2 tab. 16 ref.]-
Key words:
- zoology /
- metal ion(Ⅱ) /
- bovine serum albumin /
- fluorescence spectroscopy /
- ultraviolet spectrum
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链接本文:
https://zlxb.zafu.edu.cn/article/doi/10.11833/j.issn.2095-0756.2013.05.022
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