Open AccessPurification and partial characterization of pyruvate decarboxylase from Oryza sativa L.
Author(s) -
RIVOAL Jean,
RICARD Bérénice,
PRADET Alain
Publication year - 1990
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1990.tb19471.x
Subject(s) - pyruvate decarboxylase , oryza sativa , tetramer , pyruvate decarboxylation , biochemistry , pyruvate dehydrogenase phosphatase , chemistry , kinetics , enzyme , pyruvic acid , pyruvate dehydrogenase complex , physics , quantum mechanics , gene , alcohol dehydrogenase
Pyruvate decarboxylase(PyrDC) was purified from rice bran to a specific activity of 1 μkat/mg and partially characterized. The holoenzyme is a tetramer of two types of subunits with molecular masses 64 kDa and 62 kDa. Purified rice PyrDC exhibits positive cooperative kinetics with respect to pyruvate and functions with a significant lag phase. When compared to other plant PyrDC, the lag phase was shorter at low pyruvate concentrations and the S 0.5 was smaller. The optimum pH (6.25) was also less acidic and the enzyme retained 30% of its maximal activity at neutral pH. In contrast to other plant PyrDC, rice PyrDC could be active at the onset of anoxia and would be activated by small changes in pyruvate concentration.