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酒石酸乙酰异戊酰泰乐菌素(ATLL)是一种新的大环内酯类兽用抗菌药,研究ATLL与蛋白质的相互作用非常重要,这直接与ATLL在体内的药效相关。牛血清白蛋白(BSA)结构上与人血清白蛋白(HSA)同源,因此,常用它作研究药物与蛋白质相互作用的蛋白模型。血液中有许多金属离子,已有关于体内单一离子对药物与蛋白质相互作用影响的研究,采用多光谱方法对ATLL与BSA相互作用及Zn~(2+)和Cu~(2+)的影响进行研究。结果表明,BSA的荧光猝灭属于静态猝灭,Zn~(2+)和Cu~(2+)分别使有效猝灭常数降低和增大。主要的相互作用力为氢键和疏水作用力。ATLL改变蛋白质色氨酸和酪氨酸的微环境极性。紫外光谱分析发现,Cu~(2+)可能是通过Cu~(2+)-ATLL复合物以金属离子架桥作用来影响ATLL与BSA的作用,Zn~(2+)可能通过与ATLL的竞争作用结合BSA。红外光谱分析表明,ATLL使BSA的β-折叠和α-螺旋结构向β-转角和无规卷曲转变。这些基础数据有助于阐明在生理条件下,有无Zn~(2+),Cu~(2+)时ATLL与BSA的相互作用机制及金属离子在药物与蛋白质作用过程中对蛋白质功能的影响。
Tylosin acetyl isovalerate (ATLL) is a new macrolide antibacterial veterinary drugs, the study of ATLL and protein interactions is very important, which is directly related to the efficacy of ATLL in vivo. Bovine serum albumin (BSA) is structurally homologous to human serum albumin (HSA) and is therefore commonly used as a protein model for studying drug-protein interactions. There are many metal ions in the blood. There is a study on the interaction between drug and protein in a single ion in vivo. The interaction between ATLL and BSA and the effects of Zn 2+ and Cu 2+ are studied by using multi-spectral method the study. The results show that the fluorescence quenching of BSA belongs to static quenching, Zn 2+ and Cu 2+ decrease and increase the effective quenching constants, respectively. The main forces of interaction are hydrogen bonding and hydrophobic forces. ATLL alters the microenvironmental polarity of the protein tryptophan and tyrosine. It was found by ultraviolet spectrum that Cu 2+ could affect the effect of ATLL and BSA through metal ion bridging through Cu 2+ ion complex. Zn 2+ may compete with ATLL The role of binding BSA. Infrared spectroscopy showed that ATLL transforms the β-sheet and α-helix structures of BSA to β-turns and random coil. These basic data help elucidate the mechanism of interaction between ATLL and BSA in the presence or absence of Zn 2+ and Cu 2+ and the effect of metal ions on protein function during the interaction between drugs and proteins under physiological conditions .