Interaction of folie acid and amino acids by fluorescence spectrometry

The interactions between folie acid and amino acids including thetryptophan,tyrosine,phenylalanine were investigated by fluorescence spectroscopy under simulated physiological condition of animal body;and the binding constants and the number of binding sites were calculated with double logarithmic equation.Results show that folie acid is able to quench the fluorescence intensity of the amino acids;and the quenching of the three amino acids by folie acid is a static quenching process.Relevant thermodynamic parameters demonstrate that hydrophobic force plays a major role in the binding of folie acid with tryptophan and tyrosine,while both hydrogen bond and Van der Waals force play a major role in the binding of folie acid with phenylalanine.