Yeast copper-thionein can reconstitute the Japanese-lacquer-tree (Rhus vernicifera) laccase from the Type 2-copper-depleted enzyme via a direct copper(I)-transfer mechanism.

The Type 2-Cu-depleted laccase from the Japanese lacquer tree (Rhus vernicifera) can be reconstituted with CuSO4 aerobically and much more rapidly and efficiently under anaerobic reducing conditions. This is to be related to a more favourable conformation of a laccase in the reduced state, rather than to reduction of the metal ion. In fact, reconstitution with Cu(I)-thionein from baker's yeast (Saccharomyces cerevisiae) only proceeds under anaerobic reducing conditions, via a direct transfer of Cu(I).