QUENCHING OF FLUORESCENCE IN MEMBRANE-PROTEIN BY HYPOCRELLIN-B

The hypocrellin B (HB) was used as a fluorescence quencher to study th e basic physical characteristics of HB in membrane systems, including the diffusion speed of quencher from aqueous phase into membrane phase , the partition coefficient (P) of quencher between membrane and water , and the fluorescence quenching constant of protein (K-sv; K-q). The experimental results show that the quenching of fluorescence in membra ne protein by HB can be determined by the principle of dynamic quenchi ng. The experimental process of fluorescence quenching was observed in detail by using the ESR technique. The signal of HB- was found to ari se from an electron transfer from excited trytophan to HB.