Fluorescence Spectrometric Analysis on the Interaction between L-Cysteine and Bovine Serum Albumin

The interaction between L-cysteine(L-Cys) and bovine serum albumin(BSA) was investigated by fluorescence quenching spectrum and synchronous fluorescence spectrum.The quenching constant,binding constant,binding sites of L-Cys with BSA,and the thermodynamic parameters(△H,△G,△S)were calculated.The fluorescence of BSA was quenched by L-Cys.The fluorescence peak of BSA shifted from 350 nm to 347.5 nm.Its quenching mechanism was a dynamic process.Their interaction force was hydrophobic force.The synchronous fluorescence spectrum showed that L-Cys influenced the microenvironment around BSA.