Partial purification and characterization of a novel histidine decarboxylase from Enterobacter aerogenes DL-1.
Histidine decarboxylase (HDC) from Enterobacter aerogenes DL-1 was purified in a three-step procedure involving ammonium sulfate precipitation, Sephadex G-100, and DEAE-Sepharose column chromatography. The partially purified enzyme showed a single protein band of 52.4 kD on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH for HDC activity was 6.5, and the enzyme was stable between pH 4 and 8. Enterobacter aerogenes HDC had optimal activity at 40°C and retained most of its activity between 4 and 50°C. HDC activity was reduced in the presence of numerous tested compounds. Particularly with SDS, it significantly (p < 0.01) inhibited enzyme activity. Conversely, Ca(2+) and Mn(2+) showed prominent activation effects (p < 0.01) with activity increasing to 117.20% and 123.42%, respectively. The Lineweaver-Burk plot showed that K m and V max values of the enzyme for L-histidine were 0.21 mM and 71.39 µmol/min, respectively. In comparison with most HDCs from other microorganisms and animals, HDC from E. aerogenes DL-1 displayed higher affinity and greater reaction velocity toward L-histidine.
['Zou|Yu|Y|', 'Hu|Wenzhong|W|', 'Jiang|Aili|A|', 'Tian|Mixia|M|']
D000595:Amino Acid Sequence D000818:Animals D002848:Chromatography, DEAE-Cellulose D021902:Enterobacter aerogenes D004789:Enzyme Activation D004795:Enzyme Stability D005590:Fractional Precipitation D006640:Histidine Decarboxylase D008969:Molecular Sequence Data D010473:Perciformes D013045:Species Specificity
purification characterization histidine decarboxylase Enterobacter aerogenes