Study of the Interactions between Tetracyclines and Human Serum Albumin / 中国药房

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(?H)entropy change(?S)were computed.According to the Frster nonradiative energy transfer theory,the critical distances R0 between donators and acceptors were derived.RESULTS:The thermodynamic parameters were as follows:?H0;R0:oxytetracycline:(1.82 nm),and methacycline(2.31 nm),tetracydine(2.98 nm),doxycycline(2.26 nm).CONCLUSION:Tetracyclines can all cause HSA's fluorescence quenching.The quenching mechanism is static quenching.The main acting force between them is electrostatic attraction.