Novel bilirubin oxidase, its production and use

Claim 1

A bilirubin oxidase M-1 having the following physicochemical properties: (1) Action: Has an action to oxidize bilirubin in the presence of oxygen far into an almost colorless substance through biliverdin and then a pale violet substance, but forms no hydrogen peroxide; (2) Substrate specificity: Acts on bilirubin and to some degree on biliverdin as well as on phenol, catechol and hydroquinone; (3) Optimum pH and pH stability: Has an optimum pH in the vicinity of 5.5, and is stable between pH 5 and pH 9 for 60 minutes treatment at 37° C. (4) Optimum temperature and thermal stability: Has an optimum temperature in the vicinity of 50° C. and is stable up 55° C. for 10 minutes treatment at a pH of 7.0; (5) Molecular weight: About 83,000 (gel filtration method); (6) Isoelectric point: 3.92±0.05; (7) Interfering agent: Inhibited by sodium azide, L-ascorbic acid, dithiothreitol and potassium cyanide; (8) Visible absorption spectrum: Has an absorption maximum in the vicinity of 610 nm; (9) Sugar content: Contains about 4.5% of sugar; (10) Copper content: Contains 4 moles of copper per mole.