Abstract
CPD photolyase plays an important role in determining UV sensitivity in plants. This enzyme is grouped into two classes, class I and II. This study was aimed to characterize rice class II CPD photolyase. Crude enzyme from rice leaves was purified sequentially by ammonium sulfate precipitation, anion exchange chromatography, heparin chromatography and DNA containing CPDs affinity chromatography. CPD bound protein on affinity chromatography was released by blue-irradiation, and was used as a purified enzyme. Specific activity of this enzyme was 8,000 fold higher than that of crude enzyme. Western blot and TOF-MAS analyses of purified enzyme showed two proteins (55- and 57-kDa), while rice CPD photolyase expressed-E. coli protein did a 56-kDa protein. Both action spectra for photoreactivating CPDs of the purified enzyme and E. coli expressed enzyme showed a peak around 410 nm. Specific activity of the purified enzyme was several-times higher than that of E. coli expressed enzyme.
