Purification and Properties of a NADPH-Dependent Erythrose Reductase from the Newly Isolated Torula corallina

摘要

Torula corallina (KCCM-10171) is a yeast strain that is currently used for the industrial production of erythritol and has the highest erythritol yiled ever reported for an erythritol-producing microorganism.Production of erythritol in T.corallina is catalyzed by ertythrose reductase an enzyme that converst erythrose to erythritol using NADPH as a cofactor.In this study,Nadph-dependent erythrose reductase was purified to homogeneity from the newly isolated T.corallina The relative molecular weight of the erythrose reductase as determined by sodium dodecyl sulfate- polyacrylamide gel electrophoresis and size exclusion chromatography was 35.4 and 71.0 kDa respectively indicating that the enzyme is dimeric.This enzyme catalyzed both erythrose reduction and erythritol oxidation gboth enzyme activities required NADP(H) The pH and temperature optima for erythrose reduction and erythritol oxidation were 6.0 40deg C and 8.0,45 deg C respectively.The sequence of the first 10 amino acids of this enzyme was N-V-K-N-F-Y-Q-P-N-D The affinity (K_m= 7.12 mM)of the enzyme for erythrose was evry high resulting in no production of other polyols which may explain the high erythritol yield observed in thsi strain.