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Identification and purification of hydroxyisourate hydrolase, a novel ureide-metabolizing enzyme
We report the identification and purification of a novel enzyme from soybean root nodules that catalyzes the hydrolysis of 5-hydroxyisourate, which is the true product of the urate oxidase reaction. The product of this reaction is 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline, and the new enzyme is...
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Published in: | The Journal of biological chemistry 1999-11, Vol.274 (48), p.33863-33865 |
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Main Authors: | , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | We report the identification and purification of a novel enzyme from soybean root nodules that catalyzes the hydrolysis of
5-hydroxyisourate, which is the true product of the urate oxidase reaction. The product of this reaction is 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline,
and the new enzyme is designated 5-hydroxyisourate hydrolase. The enzyme was purified from crude extracts of soybean root
nodules â¼100-fold to apparent homogeneity with a final specific activity of 10 μmol/min/mg. The enzyme exhibited a native
molecular mass of â¼68 kDa by gel filtration chromatography and migrated as a single band on SDS-polyacrylamide gel electrophoresis
with a subunit molecular mass of 68 ± 2 kDa. The purified enzyme obeyed normal Michaelis-Menten kinetics, and the K
m for 5-hydroxyisourate was determined to be 15 μ m . The amino-terminal end of the purified protein was sequenced, and the resulting sequence was not found in any available
data bases, confirming the novelty of the protein. These data suggest the existence of a hitherto unrecognized enzymatic pathway
for the formation of allantoin. |
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ISSN: | 0021-9258 1083-351X |
DOI: | 10.1074/jbc.274.48.33863 |