抄録
1. Tuberculin active protein, hC, was treated with cysteine and thioglycollic acid but the tuberculin activity was not affected.
2. The hC was oxidized with performic acid. Tuberculin activity remained unchang-ed even after all of the cystine and/or cysteine
TABLE II Effect of Reagents on hC and Tuberculin Activity
residues were oxidized to cysteic acid.
3. When hC was photooxidized by visible light in the presence of methylene blue, inactivation of the tuberculin activity of hC took place along with the decomposi-tion of all of the histidine residues in the molecule.
4. It is probable that histidine residues are essential, but cystine or cysteine residues are not essential for the activity.
The author wished to thank Prof. Akabori, Osaka University, for his continuous interest and advice during the course of this investigation, and to thank Prof. Yamamura, Kyushu University, for his encouragement and guidance.