Properties of laccases produced by Pycnoporus sanguineus induced by 2,5-xylidine.

Two isoforms of laccase produced from the culture supernatant of Pycnoporus sanguineus were partially purified by phenyl-Sepharose chromatography. Molecular masses of the enzymes were 80 kDa (Lac I) and 68 kDa (Lac II). Optimum activity of Lac I was at pH 4.8 and 30 degrees C, and Lac II was at pH 4.2 and 50 degrees C over 5 min reaction. The Km values of enzymes toward syringaldazine were 10 microM: (Lac I) and 8 microM: (Lac II). Sodium azide inhibited Lac I (85%) and Lac II (75%) activities.