红曲菌两种荧光代谢产物与BSA相互作用的光谱法研究

Investigation of interaction between two monascus metabolites and BSA by spectroscopy

运用紫外光谱和荧光光谱法研究了红曲菌两种荧光代谢产物与BSA的相互作用,并探讨了其结合类型、结合常数及结合过程中热力学参数。结果表明:红曲菌两种荧光代谢产物(monasfluore A,MFA和monasfluore B,MFB)结合BSA内源荧光的猝灭是由于红曲菌荧光代谢产物与BSA之间形成复合物,符合动态猝灭机理。298、308、318K下,MFA与BSA和MFB与BSA的结合常数分别为:3.47×1012、6.35×1012、7.94×1012L·mol-1和6.90×1012、1.19×1013、1.75×1013L·mol-1。热力学数据表明红曲菌两种荧光代谢产物与BSA之间主要作用力为疏水作用力,且MFB与BSA作用明显强于MFA与BSA之间作用,可能由于MFB含有辛基侧链,疏水性明显强于含己基侧链的MFA,故MFB通过疏水作用与BSA作用更明显。

The interaction between two monascus metabolites and BSA were investigated using fluorescence and UV spectroscopy.The binding mode and thermodynamic parameters between two monascus metabolites and BSA were studied. The results showed that two monascus metabolites have the ability to quench the intrinsic fluorescence of BSA,and the quenching mechanism dynamic quenching.The binding constants of MFA-BSA and MFB- BSA were 3.47 × 1012,6.35 × 1012,7.94 ×1012 L. mol - 1 and 6.90×1012, 1.19 ×1013,1.75 ×1013 L. mol -1 at 298,308, 318K,respectively.MFA was a lower homologue of MFB,with the less lipophilic hexanoyl instead of octanoyl side chain,and these resulted in a less interaction with BSA.