[Damage analyse of X-ray radiated cellobiohydrolase II molecule from Trichoderma viride]

After X-ray treatment at 1.82 keV and 40 mA and 4 hours, the cellobiohydrolase II (CBH II) aqueous solution of Trichoderma viride was analysed, and the damage state of the irradiated molecule was detected using some cysteine residue relative parameters in Raman spectroscopic methods. The results show that S-H stretch modes of CBH II exhibited some shift, which means that the hydrogen proton donor state of sulfhydryl groups was stronger and weaker, respectively. The 2 554 cm(-1) peak of irradiated sample was wide. The -S-S- construction of disulfide bonds was not broken, and the geometrical conformation types did not change either, but its bond length was somewhat shortened. Before irradiation, C-S isomer mode content of cysteine residue was Pc type slightly more than both P(N) and P(H) types, while P(N) and P(H) types increased after irradiation. Besides, CH2 rocking mode of cysteine residue was weakened remarkably after the treatement, and the protein molecule structure did not show important damage in sulfhydryl and disulfide bonds, but showed some change because of the X-ray irradiation condition.