Abstract：It is obvious that the albumin is a kind of important large biophysical molecular. The albumin is the main component of plasma within cell. It is also the matter basis of life phenomenon. The fluorescence spectroscopy of humen serum albumin(HSA) and the interaction of HSA and the rifampicin capsules (lfp) were studied. When the rifampicin capsules(lfp) was added into HSA solution gradually, an interesting new phenomenon emerged in emission spectrum. The combination constant of rifampicin capsules(lfp) is about Kｓ=5.149×104 L·mol-1,and the dissociation constant is about Kd=19.42×10-6 mol·L-1. The quenching process of rifampicin capsules(lfp)-HSA is not dynamic quenching, which resulted from the molecular diffusion and collision. That is the static quenching process resulting from the chemical component between molecules. The energy transfer efficiency between rifampicin capsules(lfp) and HSA is E=0.42. According to these calculation results, the combination position between the binding site of rifampicin capsules(lfp) and the tryptophane of HSA is about R=2.567 nm. The critical distance, when transfer efficiency equals 50%, is about R0=2.433 nm.
Key words：Rifampicin capsules(lfp);Fluorescence quenching;Humen serum albumin
