Heterologous expression of two minor laccase isozyme cDNAs from the edible mushroom Grifola frondosa.

Two cDNAs encoding the minor laccase isozymes (Lac2 and Lac3) of Grifola frondosa were cloned, characterized, and expressed in Pichia pastoris. The recombinant Lac2 (rLac2) was stable at pH 6.0, whereas the recombinant Lac3 (rLac3) was stable in a broad pH range (pH 4.0-8.0). In addition, rLac2 and rLac3 showed the highest catalytic efficiency (kcat /Km ) for 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid).