1956 年 43 巻 6 号 p. 803-810
1. Phenol, pyruvate and NH3 are produced from tyrosine by the β-tyrosinase, obtained from B. coli phenologenes, in an equimolar ratio simultaneously.
2. Pyridoxal phosphate is the coenzyme of the β-tyrosinase.
3. For this reaction, the presence of NH4+ or K+ is required and Na+ or Li+ counteract K+ or NH4+ activation. The previous report was thus corrected.
4. This enzyme is inhibited by metal chelating compounds. Therefore, the participation of a certain heavy metal is suggested.
5. This enzyme is also inhibited by various SH reagents, and regains its activity by the addition of mercapto compounds. Concequently the participation of the SH group is suggested.
6. The mechanism of the enzymatic reaction is discussed.