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在模拟人体生理条件下(pH 7.4),采用荧光光谱法研究了瑞香黄烷A(DPA)和瑞香黄烷B(DPB)与牛血清白蛋白(BSA)的相互作用。DPA和DPB通过静态猝灭过程使得BSA荧光强度减弱;在25℃下,DPA和DPB与BSA结合常数分别为3.35×106L.mol-1和7.36×106L.mol-1,结合位点数分别为1.073和1.196;通过计算反应热力学参数值,可推断DPA和DPB与BSA作用力主要为氢键或范德华力;根据Foerster非辐射能量转移理论计算DPA和DPB与BSA的结合距离分别为3.11nm和3.04nm;同步荧光光谱法研究表明,DPA和DPB与BSA的结合对蛋白质的构象未产生影响,其结合位点更接近于色氨酸;同时还考察了部分共存金属离子对DPA和DPB与BSA结合作用的影响。
Fluorescence spectroscopy was used to study the interaction of daphia flavin A (DPA) and daphia flavan B (DPB) with bovine serum albumin (BSA) under simulated human physiological conditions (pH 7.4). DPA and DPB decreased the fluorescence intensity of BSA through static quenching process; the binding constants of DPA and DPB to BSA were 3.35 × 106L.mol-1 and 7.36 × 106L.mol-1 respectively at 25 ℃, the number of binding sites were 1.073 And 1.196, respectively. By calculating the values of the reaction thermodynamic parameters, it can be inferred that the interaction forces between DPA and DPB and BSA are mainly hydrogen bonds or van der Waals forces. According to Foerster’s non-radiative energy transfer theory, the binding distances of DPA and DPB to BSA are 3.11 nm and 3.04 nm The results of synchronous fluorescence spectroscopy showed that the binding of DPA and DPB to BSA had no effect on the conformation of the protein, and the binding site was closer to tryptophan. The coexistence of some metal ions on the binding of DPA and DPB to BSA Impact.