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PURIFICATION AND CHARACTERIZATION OF A MALATE DEHYDROGENASE FROM PHASEOLUS MUNGO
Author(s) -
WANG SHAOYUN,
XU ZHIBIN,
YE XIUYUN,
RAO PINGFAN
Publication year - 2005
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.2005.00017.x
Subject(s) - malate dehydrogenase , phaseolus , ammonium sulfate precipitation , isoelectric focusing , size exclusion chromatography , sephadex , chromatography , biochemistry , isoelectric point , citrate synthase , molecular mass , biology , amino acid , ion chromatography , enzyme , chemistry , botany
ABSTRACT A malate dehydrogenase (MDH) was identified and isolated from the seeds of the mung bean ( Phaseolus mungo ). The procedure entailed extraction, ammonium sulfate precipitation, ion exchange chromatography on CM‐Sephadex and high performance liquid chromatography on POROS HS‐20. The purified protein exhibited a molecular mass of 38 kDa in SDS‐polyacrylamide gel electrophoresis under both nonreduced and reduced conditions. The pI was 9.7 by isoelectric focusing. The specific activity of the MDH was estimated to be 199 U/mg. The enzyme expressed its optimum activity at pH 7.2, 35C, and showed stable activity below 40C. The Km for oxaloacetate was 112 µM. The partial N‐terminal amino acid sequence data analysis of the first 20 amino acids of the mung bean MDH revealed 95 and 80% homology with two reported MDH from soya bean ( Glycine max ) and potato ( Solanum tuberosum ), respectively.