目的 在生理條件下使用紫外光譜法、熒光光譜法以及分子對接研究甲苯磺丁脲與乳清蛋白的相互作用。方法 實驗選取激發(fā)波長280 nm，測定不同溫度下甲苯磺丁脲與乳清蛋白的熒光猝滅光譜；通過相關(guān)參數(shù)（結(jié)合常數(shù)、結(jié)合位點數(shù)等）的計算以及熱力學參數(shù)判斷猝滅機制、甲苯磺丁脲與乳清蛋白的相互作用特點以及乳清蛋白構(gòu)象的變化，并通過分子對接方法探究藥物與乳清蛋白之間可能存在的作用形式。結(jié)果 甲苯磺丁脲可使乳清蛋白內(nèi)源熒光發(fā)生作用機制為復合式靜態(tài)猝滅的猝滅；以氫鍵、范德華力為主要作用力類型；甲苯磺丁脲與乳清蛋白結(jié)合過程中存在非輻射能量轉(zhuǎn)移，促使乳清蛋白的熒光猝滅；藥物與蛋白的結(jié)合對乳清蛋白的構(gòu)象無明顯影響；分子對接結(jié)果表明：甲苯磺丁脲分別與Glu113殘基形成1個氫鍵，與Asp116殘基形成2個氫鍵以及與Glu121殘基形成2個氫鍵。結(jié)論 甲苯磺丁脲與乳清蛋白可以發(fā)生相互作用，因此建議甲苯磺丁脲不要和牛奶同服。

Objective To study the interaction between tolbutamide and lactalbumin under physiological conditions via fluorescence spectroscopy, ultraviolet spectroscopy and molecular docking. Methods The excitation wavelength of 280 nm was selected to measure the fluorescence quenching spectra at different temperatures. The quenching mechanism, the interaction characteristics between drug and lactalbumin, and the changes in the conformation of lactalbumin were determined by calculating related parameters (binding constant, number of binding sites, etc.) and thermodynamic parameters. The possible forms of interaction between drug and lactalbumin were explored by molecular docking method. Results Tolbutamide can cause lactalbumin endogenous fluorescence to occur by quenching by composite static quenching; the main force types are hydrogen bond and van der Waals force; It was inferred that non-radiative energy transfer occurred during the binding of tolbutamide to lactalbumin, which promoted the quenching of lactalbumin. Synchronous fluorescence spectroscopy, ultraviolet absorption spectroscopy and three-dimensional fluorescence spectra showed that the binding reaction had no obvious effect on the conformation of lactalbumin. The molecular docking results showed that tolbutamide formed one hydrogen bond with Glu113 residue, two hydrogen bonds with Asp116 residue and two hydrogen bonds with Glu121 residue. Conclusion Tolbutamide can spontaneously interact with lactalbumin. It is suggested that tolbutamide should not be taken with milk.

R657.3

陜西省重點研發(fā)計劃項目（2020ZDLSF05-12、2022ZDLSF05-07）