Ureide catabolism in soybeans. III. Ureidoglycolate amidohydrolase and allantoate amidohydrolase are activities of an allantoate degrading enzyme complex

Journal Article · Thu Mar 31 23:00:00 EST 1988 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.86.4.1084· OSTI ID:6994849

Winkler, R G; Blevins, D G; Randall, D D ^[1]

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1. Univ. of Missouri, Columbia (USA)

The authors demonstrate that allantoate is catabolized in soybean seedcoat extracts by an enzyme complex that has allantoate amidohydrolase and ureidoglycolate amidohydrolase activities. Soybean seedcoat extracts released {sup 14}CO{sub 2} from (ureido-{sup 14}C)ureidoglycolate under conditions in which urease is not detectable. CO{sub 2} and glyoxylate are enzymatically released in a one to one ratio indicating that ureidoglycolate amidohydrolase is the responsible activity. Ureidoglycolate amidohydrolase has a K{sub m} of 85 micromolar for ureidoglycolate. Glyoxylate and CO{sub 2} are enzymatically released from allantoate at linear rates in a one to 2.3 ratio from 5 to 30 min. That ({sup 14}C)urea production from (2,7-{sup 14}C)allantoate is not detectable indicates that allantoate-dependent glyoxylate production is enzymic and not a result of nonenzymatic hydrolysis of a ureido intermediate (nonenzymatic hydrolysis releases urea). The results suggest that soybeans have a second amidohydrolase reaction that follows allantoate amidohydrolase in allantoate catabolism. The rate of {sup 14}CO{sub 2} release from (2,7-{sup 14}C)allantoate is not reduced when the volume of the reaction mixture is increased, suggesting that the release of {sup 14}CO{sub 2} is not dependent on the accumulation of free intermediates. That (2,7-{sup 14}C)allantoate dependent {sup 14}CO{sub 2} release is not proportionally diluted by unlabeled ureidoglycoalte indicates that the reaction is carried out by an enzyme complex.

• OSTI ID: 6994849
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 86:4; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ALLANTOIN
AMIDES
AZOLES
BIOCHEMICAL REACTION KINETICS
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONIC ACID DERIVATIVES
CARBOXYLIC ACIDS
CATABOLISM
CHALCOGENIDES
ENZYME ACTIVITY
ENZYMES
GLYCINE HISPIDA
GLYOXYLIC ACID
HETEROCYCLIC COMPOUNDS
HYDROLASES
IMIDAZOLES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LEGUMINOSAE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
METABOLISM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANTS
REACTION KINETICS
SEEDLINGS
TRACER TECHNIQUES
UREA