丹参酚酸A和丹参酚酸B与胰岛素相互作用的分子光谱学研究以及葡萄糖的影响

采用紫外-可见光谱、荧光光谱和傅里叶变换衰减全反射红外光谱等技术，研究在模拟人体生理Ph值条件下，丹参酚酸A(或丹参酚酸B)与胰岛素分子之间的结合作用，以及丹参酚酸A(或丹参酚酸B)对胰岛素二级结构的影响，并考察葡萄糖对它们的影响。实验结果表明，丹参酚酸A和丹参酚酸B均能导致胰岛素内源性荧光静态猝灭;同步荧光和三维荧光谱图表明胰岛素与丹参酚酸A(或丹参酚酸B)结合后，构象没有发生明显变化。红外光谱研究表明，胰岛素与丹参酚酸A(或丹参酚酸B)结合后二级结构发生了一些改变，β-转角和无规则卷曲的相对含量略有增加，α-螺旋和β-折叠没有发生明显改变。葡萄糖的加入会改变丹参酚酸A(或丹参酚酸B)与胰岛素的结合程度，并加剧胰岛素构象变化以及二级结构中α-螺旋相对含量改变，从而影响丹参酚酸A(或丹参酚酸B)-胰岛素体系中胰岛素的生物活性。

Research on Molecular Spectra of Interactions Between Salvianolic Acid A and Salvianolic Acid B with Insulin,and Effect of Glucose on the Binding

The interactions of Salvianolic acid A (SAA)and Salvianolic acid B (SAB)with insulin were studied by using fluorescence spectroscopy,UV-vis spectroscopy and ATR-FTIR spectroscopy in simulating physio-logical condition (pH 7.40).The fluorescence quenching of insulin by SAA and SAB were static quenching process.The results of synchronous fluorescence and three-dimensional fluorescence spectra suggested no ob-vious conformation changes of insulin after SAA or SAB binding.But ATR-FTIR spectra showed that SAA and SAB could change the secondary structures of insulin,of whichβ-turns decreased and random coil in-creased accompanied withα-helices andβ-sheets no clear change.The glucose might influenced the the bioactiv-ity of insulin in the SAA-insulin and SAB-insulin systems by changing the binding constants of SAA (or SAB) with insulin and exacerbating the changes of insulin conformation and relative contents ofα-helices.