THE RESEARCH OF THE TRYPTOPHAN RESIDUES'''' SPECTRUM IN bR WHEN OXIDIZED BY N-BROMOSUCCINIMIDE
N-溴代琥珀酰亚胺修饰菌紫质中色氨酸的光谱学研究

The number of oxidized Tryptophan(Trp)of all the eight Trp residues of bR and the corresponding spectrum change when modified by N-bromosuccinimide(NBS)gradually(redox)via UV-Vis absorption spectrum and fluorescence spectrum were researched.The results revealed that the number of oxidized Trp residues is about 4 when increasing the NBS/bR molar ratio normally,but if more NBS is used,This number will rise to 6~7.The Trp residues' characteristic fluorescence peak will be decreased and blue-shifted during the chemical modification.Results revealed still that there may be three different kinds of Trp residue structure in bR.The research results are important and meaningful for making clear the Trp-retinal coupling energy transfer,the fluorescence lifetime of individual Trp residue and the role of Trp residues in membrane protein's structure and function.