Abstract： The interaction between cucurbit[7]uril(CB[7]) and bovine serum albumin(BSA) was first studied by fluorescence spectroscopy.In pH 7.4 Tris buffers,the intrinsic fluorescence quenching of BSA dropped with the increase of the concentration of CB[7].The quenching constant decreased with the rise of the temperature.As a result of the formation of CB[7]-BSA complex,the fluorescence quenching was static.The data related were analyzed according to the Stern-Volmer equation and the Lineweaver-Burk double-reciprocal equation.The binding constant,binding site number and the thermodynamic parameters were obtained at different temperatures.At 298 K,the apparent binding constant(KA) was 2.337×105 L · mol-1,and the binding sites is 1.078.Based on the thermodynamic parameter analysis,the hydrophobic and electrostatic interactions were the main force between CB[7]and BSA.On the one hand,the amino acid residues of BSA on the part of non-polar groups could enter the CB [7] hydrophobic cavity.On the other hand,BSA might be able to protonated carbonyl electrostatic interaction with CB [7] easily.Synchronous fluorescence indicated that CB [7] did not produce changes in the conformation of BSA,which could provide useful information for the development and utilization of cucurbiturils in the field of biology and drug carriers.
2012, Vol. 36 
