Open AccessHigh catalytic activity of alanine racemase from psychrophilic Bacillus psychrosaccharolyticus at high temperatures in the presence of pyridoxal 5′‐phosphate
Author(s) -
Okubo Yoko,
Yokoigawa Kumio,
Esaki Nobuyoshi,
Soda Kenji,
Misono Haruo
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb09377.x
Subject(s) - psychrophile , thermophile , pyridoxal , pyridoxal phosphate , cofactor , enzyme , biochemistry , alanine , chemistry , catalysis , enzyme assay , amino acid
We examined the effect of the pyridoxal 5′‐phosphate (PLP) cofactor on the activity and stability of the psychrophilic alanine racemase, having a high catalytic activity at low temperature, from Bacillus psychrosaccharolyticus at high temperatures. The decrease in the enzyme activity at incubation temperatures over 40°C was consistent with the decrease in the amount of bound PLP. Unfolding of the enzyme at temperatures above 40°C was suppressed in the presence of PLP. In the presence of 0.125 mM PLP, the specific activity of the psychrophilic enzyme was higher than that of a thermophilic alanine racemase, having a high catalytic activity at high temperature, from Bacillus stearothermophilus even at 60°C.