|
type |
Journal Article |
authors |
Izumi, Y.; Yoshida, T.; Yamada, H. |
title |
Purification and characterization of serine-glyoxylate aminotransferase from a serine-producing methylotroph, Hyphomicrobium methylovorum GM2 |
journal |
Eur J Biochem |
Activity |
2.6.1.45 |
ui |
90306025 |
year |
(1990) |
volume |
190 |
number |
2 |
pages |
285-90. |
| |
keywords |
Bacteria/*enzymology |
abstract |
Serine--glyoxylate aminotransferase was purified to complete homogeneity from a serine-producing methylotrophic bacterium, Hyphomicrobium methylovorum GM2, which possesses the serine pathway. This is the first microbial serine--glyoxylate aminotransferase to be purified. The enzyme has a molecular mass of about 140 kDa and consists of four subunits of identical mass, i.e. 40 kDa. The holoenzyme exhibited absorption maxima at 282 nm and 408 nm, and a shoulder at about 315-345 nm in potassium phosphate pH 7.0; it contained 4 mol pyridoxal 5'-phosphate/mol enzyme. Isoelectric focusing showed that the enzyme had a pI value of 6.9. The Km values for glyoxylate and L-serine were 0.23 mM and 4.98 mM, respectively, and the enzyme showed high specificity for these substrates. The transamination between glyoxylate and L-serine seemed to be nearly irreversible. These data indicated that this serine--glyoxylate aminotransferase plays an essential role in methanol assimilation through the serine pathway in H. methylovorum GM2. |
last changed |
2002/11/12 16:17 |
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