A cDNA encoding putative thioredoxin reductase (TR) was identified from a medicinal mushroom, Taiwanofungus camphorata (T. camphorata). Alignment of the deduced amino acid sequence with TRs from other organisms showed high levels of identity (59-74%). A three-dimensional (3-D) homology structure was created for this TR. Functional T. camphorata TR (TcTR) was overexpressed in yeast and purified. The purified enzyme showed a monomic form on a 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme's half-life of deactivation at 60 °C was 12.9 min, and its thermal inactivation rate constant Kd was 5.37 ×10-2 min-1. The optimal pH for the enzyme was pH 8 and retained about 76% activity in the presence of 0.1 M imidazole. The enzyme showed 50% activity after 10 min of incubation at 37 °C with chymotrypsin. The Michaelis constant (K m) value for dithionitrobenzoate (DTNB) was 1.59 mM.
All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences(all)