四环素类药物与人血清蛋白的结合作用研究

目的:探讨四环素类药物(土霉素、美他环素、四环素、多西环素)与人血清蛋白(HSA)的相互作用。方法:利用紫外吸收光谱和荧光光谱研究不同温度下四环素类药物与HSA的结合常数和结合点数,计算焓变(ΔH)、熵变(ΔS);依据Frster非辐射能量转移理论,得到供体与受体间的临界距离R0。结果:热力学参数ΔH<0,ΔS>0;R0分别为土霉素1.82nm,美他环素2.31nm,四环素2.98nm,多西环素2.26nm。结论:四环素类药物都能使HSA的荧光发生猝灭,其猝灭机制为静态猝灭;二者之间的主要作用力为静电引力。

Study of the Interactions between Tetracyclines and Human Serum Albumin

OBJECTIVE： To discuss the interactions between tetracyclines （oxytetracycline, methacycline, tetracydine, and doxycycline） and human serum albumin （HSA） . METHODS： The binding constants and the number of biding sites of tetracyclines with human serum albumin（HSA） at various temperatures were studied by using UV - visible absorption spectrum and spectrofluorimetry, and the enthalpy change （AH） entropy change （AS） were computed. According to the F6rster nonra- diative energy transfer theory, the critical distances R0 between donators and acceptors were derived. RESULTS： The thermodynamic parameters were as follows： AH〈0, and AS〉 0; R0： oxytetracycline： （1.82 nm）, and methacycline （2.31 nm）, tetracydine （2.98 nm）, doxycyeline （2.26 nm）. CONCLUSION： Tetracyelines can all cause HSA＇s fluorescence quenching. The quenching mechanism is static quenching. The main acting force between them is electrostatic attraction.