关键词: 细胞色素C, 脲, 同步荧光光谱

Abstract: The states of cytochrome Cmolecules in aquous solution were studied with synchronous fluorescence spectroscopy.It was found that the synchronous fluorescent spectra of cytochrome Cwere contribuited by tyrosine and tryptophan residues separately at △λ=20 nm and △λ=80 nm.The peak position in synchronous fluorescent spectra of tyrosine residues in cytochrome Cmolecule does not change with its concentriation,but that of tryptophan residue changes with its concentration.Only one peak at 340.0 nm was observed in the dilute solution of cytochrome C.With increasing the concentration of cytochrome C,a new peak at 304.0 nm appeared.The peak at 340.0 nm disappeared and only one peak at 304.0 nm was obderved at a higher concentration of cytochrome C.It may originate from the change of aggregation states of cytochrome Cmolecules and it was considered that the peak at 340.0 nm was attributed to the monomer and peak at 304.0 nm was due to the dimmer or oligomers.When urea was added into cytochrome Csolution in which both monomer and dimmer or oligomers exist,cytochrome Cmolecules do not denature in the range of the specific concentrations of urea.The concentration of monomer of cytochrome Cmolecules increased and that of aggregation states decreased by adding urea.Therefore,the synchronous fluorescence spectroscopy can be used to identify monomer and aggregation states of cytochrome Cmolecules.

Key words: Cytochrome C, Urea, Synchronous fluorescence spectroscopy