Short communication Purification and Storage of Ribulose 1,5-bisphosphate Carboxylase

Ribulose 1,5-bisphosphate (RuBP) carboxylase was purified from rice leaves. By using a buffer containing 12.5 % (v/v) glycerol throughout purification, the enzyme was protected from cold lability and was obtained at a high yield (5.5 mg/g fresh wt). The purified enzyme exhibited different rates of CO2/Mg2+-activation by temperature pretreatment/storage. The purified enzyme was stable for at least one year in phosphate buffer containing 12.5 % (v/v) glycerol at 4°C or 50 % (v/v) glycerol at-20°C. Key words: Oryza saliva — Ribulose 1,5-bisphosphate carboxylase. RuBP carboxylase (EC 4.1.1.39) catalyzes two reactions; carboxylation (Weissbach et al. 1956) and oxygenation (Bowes et al. 1971) of RuBP. The former reaction is the CO2 fixation in the photosynthetic carbon reduction cycle and the latter is the 2-phosphoglycolate production in the photorespiration pathway. The enzyme requires prior activation with CO2 and Mg2+ to catalyze both reactions (Lorimer et al. 1976, Badger and Lorimer 1976). RuBP carboxylases have been purified from a number of photosynthetic organisms and their properties have also been studied. Concerning rice leaf enzyme, however, only a few studies hav