Abstract:The ultraviolet/visible spectra of TOP Ⅰ were studied. It was proved that TOP Ⅰ is an acid enzyme containing hemochrome as an agon. When the pH reduced, the Soret absorption in UV-Vis region exhibited a blue shift,when pH increased it exhibited a red shift. The result of the influence of carbamide, the denaturant, on the spectra showed that TOP Ⅰ may have a unfolded structural change in the solution, which made the peptide chain completely extend. After adding Fe(Ⅲ), Fe(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ), Ni(Ⅱ) and Sn(Ⅱ) to the apo-TOP Ⅰ, the UV-Vis spectra changed except for Fe(Ⅲ), which almost did not change at all. The strongest characteristic absorption peak of the Soret showed a blue shift to different extent and it became weak gradually. The situation of α-strip and β-strip remained unchanged while the relative strength decreased.
[1] GUO Yao-jun(郭尧君). Technique of Spectral Photometer and Its Application in Biochemistry(分光光度技术及其在生物化学中的应用). Beijing: Science Press(北京:科学出版社),1987. [2] Perkampus Heinz-Helmut. Translated by Charlotte Grinter H and Threlfall Borlin T L. UV-Vis Spectroscopy and Its Applications. New York: Springer-Verlag, 1992. [3] Braun R D. Introduction Instrumental Analysis. New York: McGraw-Hill, 1987. [4] Douglas A S,Donald M W. Principles of Instrumental Analysis. 2nd ed. Philadelphia: Saunders College, 1980. [5] Williams D H,Fleming I. Spectroscopic Methods in Organic Chemistry. 3rd ed. London: McGraw-Hill, 1980. [6] Freifelder D. Physical Biochemistry Applications to Biochemistry and Molecular Biology. W.H.Freeman and Company, 1976. [7] Haschemeyer R H et al. Proteins, A Guide to Study by Physical and Chemical Methods. John Wiley and Sons, Inc., 1973. [8] JIA Ying-ping, ZHENG Xue-fang, HU Jie-han(贾颖萍,郑学仿,胡皆汉). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2001, 21(2): 222.