Purification and some properties of a novel racemase, which racemizes 2-oxothiazolidine-4-carboxylic acid and 5-oxoproline, from Flectobacillus sp. strain B-1.
A novel racemase active toward 2-oxothiazolidine-4-carboxylic acid was purified 310-fold with 5% recovery to near homogeneity from a crude extract of Flectobacillus sp. B-1, which had been isolated as a bacterium being able to assimilate (S)-2-oxothiazolidine-4-carboxylic acid. The molecular weight was estimated to be 92,000 by gel filtration. The purified preparation migrated as a single band of molecular weight 49,000 upon SDS-polyacrylamide gel electrophoresis. The enzyme exhibited maximum activity at pH 8.0 and 45 degrees C. The enzyme also racemized 5-oxoproline but did not act on proline and 4-hydroxyproline. The enzyme apparently had no coenzyme requirement. The enzyme activity was inhibited to 62-100% by SH-blocking reagents such as HgCl2, AgNO3, PCMB, iodoacetamide, N-ethylmaleimide and N-bromosuccinimide.
Mochizuki
K
K
National Institute of Bioscience and Human-Technology, Agency of Industrial Science and Technology, Ibaraki, Japan.
Hosono
K
K
Kobayashi
H
H
D001407:Bacillus / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011761:Pyrrolidonecarboxylic Acid / Q000378:metabolism*; D019998:Racemases and Epimerases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D013696:Temperature; D013844:Thiazoles / Q000378:metabolism*; D053778:Thiazolidines
D013844:Thiazoles; D053778:Thiazolidines; D019998:Racemases and Epimerases; D011761:Pyrrolidonecarboxylic Acid; C029536:2-oxothiazolidine-4-carboxylic acid