Binding of isofraxidin to bovine serum albumin.
The binding of isofraxidin to bovine serum albumin (BSA) was studied under physiological conditions with BSA concentration of 1.5 x 10(-6) mol x L(-1) and drug concentration in the range of 1.67 x 10(-6) mol x L(-1) to 2.0 x 10(-5) mol x L(-1). Fluorescence quenching spectra in combination with uv absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and CD spectroscopy was used to determine the drug-binding mode, binding constant, and the protein structure changes in the presence of isofraxidin in aqueous solution. The linearity of Scatchard plot indicates that isofraxidin binds to a single class of binding sites on BSA and the values given for the binding constants agree very closely with those obtained by the modified Stern-Volmer equation. The thermodynamic parameters, enthalpy change (DeltaH) and entropy change (DeltaS), were calculated to be -17.63 kJ x mol(-1) and 51.38 J x mol(-1) x K(-1) according to the van't Hoff equation, which indicated that hydrophobic interaction played a main role in the binding of isofraxidin to BSA.
Liu
Jiaqin
J
Department of Chemistry, Lanzhou University, Lanzhou 730000, China.
Tian
Jianniao
J
Hu
Zhide
Z
Chen
Xingguo
X
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism; D003374:Coumarins / Q000737:chemistry / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D017433:Protein Structure, Secondary; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D003374:Coumarins; D014867:Water; D012710:Serum Albumin, Bovine; C008182:isofraxidin