|
type |
Journal Article |
authors |
Liu D., Liu X., Zhang L., Jiao H., Ju J., Zhao B. |
title |
Biochemical characteristics of an alanine racemase from Aeromonas hydrophila HBNUAh01 |
journal |
Microbiology |
Activity |
5.1.1.1 |
Family |
5.1.1.1.a |
sel |
selected |
ui |
HBNUAh01 |
year |
(2015) |
volume |
84 |
number |
2 |
pages |
202–209 |
| |
keywords |
doi:10.1134/S0026261715020071 |
abstract |
We reveal that the genome of Aeromonas hydrophila HBNUAh01has an alanine racemase gene (alr-2); this gene encodes a functional enzyme that can complement the alanine racemase deficiency of Escherichia coli strain MB2795. The gene alr-2 was cloned and expressed in E. coli BL21 (DE3). The gene has an open reading frame (ORF) of 1230 bp encoding a protein of 369 amino acids with a calculated molecular mass of 40.39 kD. The amino acid sequence deduced revealed similarity of 98, 84 and 68% with alanine racemases from A. hydrophila ATCC7966, Aeromonas caviae_Ae398, Aeromonas vickers_b565, respectively. The optimal temperature and pH for enzyme activity was 37°C and pH 10. The enzyme had broad substrate specificity. The alanine racemase was shown to belong to the pyridoxal 5′-phosphate (PLP)-dependent family of enzymes that require a certain concentration of PLP for activity. The kinetic parameters Km and Vmax at 40°C of alanine racemase were 35.9 mM, 2898 units/mg for L-alanine and 15.36 mM, 1209 units/mg for D-alanine, respectively. |
last changed |
2017/07/12 13:02 |
|