|
type |
Journal Article |
authors |
Kamitani, H.; Esaki, N.; Tanaka, H.; Imahara, H.; Soda, K. |
title |
Purification and characterization of S-alkylcysteine alpha,beta-lyase from Pseudomonas putida |
journal |
J Nutr Sci Vitaminol (Tokyo) |
Activity |
4.4.1.6 |
sel |
selected |
ui |
2081976 |
year |
(1990) |
volume |
36 |
number |
4 |
pages |
339-47 |
| |
keywords |
Amino Acids/metabolism |
abstract |
S-Alkylcysteine alpha,beta-lyase [EC 4.4.1.6] was purified to more than 90% homogeneity from the cell extract of Pseudomonas putida ICR 3640. The enzyme has a molecular weight of about 195,000, and is composed of six subunits identical in molecular weight (37,000). Pyridoxal 5'- phosphate is required as a cofactor. The enzyme catalyzes the alpha,beta-elimination of S-methyl-L-cysteine and its analogs such as S- ethyl-L-cysteine, L-djenkolate, Se-methyl-DL-selenocysteine, and O- methyl-L-serine. However, S-methyl-D-cysteine, L-methionine, and L- norvaline were inert. The enzyme catalyzes also the beta-replacement reaction of the thiomethyl group of S-methyl-L-cysteine with various thiols to yield the corresponding S-substituted cysteines. In addition to S-methyl-L-cysteine, Se-methyl-DL-selenocysteine and O-methyl-L- serine also serve as substrates in the beta-replacement reaction. |
last changed |
2009/07/01 10:57 |
|