Pyridine nucleotide-dependent reduction of the α-keto acid analogue of lysine to L-pipecolic acid

It was found that γ-methyleneglutamic acid, γ-methylglutamic acid, and their keto-acid analogues are natural constituents of Lilium regale. These compounds were not present in the seed but appeared soon after germination. It was shown that, in seedlings, these compounds are not formed from atmospheric carbon dioxide either in the light or in the dark. This was shown also for excised leaves under a variety of conditions. In entire young plants a synthesis of γ-methyleneglutamic acid was demonstrated in the bulbs and roots. The keto-acid analogue was synthesized in all parts of the plant including the leaves. The results suggest that the accumulation of γ-methyleneglutamic acid in leaves is through transport from the subterranean organs of the plant where it is synthesized.

Download Full-text

BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: VI. BIOSYNTHESIS OF GLUCOBARBARIN IN RESEDA LUTEOLA L.

Canadian Journal of Biochemistry ◽

10.1139/o65-026 ◽

1965 ◽

Vol 43 (2) ◽

pp. 189-198 ◽

Cited By ~ 12

Author(s):

E. W. Underhill

Keyword(s):

Specific Activity ◽

Mustard Oil ◽

Keto Acid ◽

Carbon 14 ◽

Acid Analogue ◽

Phenylbutyric Acid ◽

Carboxyl Carbon

A number of C14-labelled compounds were fed to Reseda luteola L.; after a 24-hour period of metabolism, the thioglucoside aglycone (5-phenyl-2-oxazolidinethione) was isolated and its specific activity determined. In some instances the aglycone was degraded to determine the distribution of C14.DL-γ-Phenylbutyrine (2-amino-4-phenylbutyric acid) was the most efficient precursor of the aglycone, followed by phenylalanine and acetate; the carboxyl carbon of these compounds was not incorporated into the thioglucoside aglycone. Little or no randomization of C14 in the aglycone resulted from feeding DL-γ-phenylbutyrine-2- and -3-C14, DL-phenylalanine-2- and -3-C14, and acetate-2-C14. The conversion of C14 from 10 additional compounds into the aglycone was less than that from D-glucose-G-C14. Isotope competition experiments suggest that β-benzylmalic acid also may be a precursor. It appears that the C6–C3 aglycone is formed from phenylalanine and acetate via C6–C5 and C6–C4 intermediates (including γ-phenylbutyrine or its keto acid analogue) in a manner analogous to the formation of gluconasturtiin in watercress. The carbon-14 and nitrogen-15 of L-phenylalanine-G-C14-N15 and of DL-γ-phenylbutyrine-2-C14-N15 were not incorporated as a unit into the aglycone of glucobarbarin.

Download Full-text

Identification of an Archaeal 2-Hydroxy Acid Dehydrogenase Catalyzing Reactions Involved in Coenzyme Biosynthesis in Methanoarchaea

Journal of Bacteriology ◽

10.1128/jb.182.13.3688-3692.2000 ◽

2000 ◽

Vol 182 (13) ◽

pp. 3688-3692 ◽

Cited By ~ 45

Author(s):

Marion Graupner ◽

Huimin Xu ◽

Robert H. White

Keyword(s):

Escherichia Coli ◽

Pyridine Nucleotide ◽

Small Extent ◽

Gene Products ◽

Pyridine Nucleotides ◽

Keto Acid ◽

Coenzyme M ◽

Methanothermus Fervidus ◽

Coenzyme Biosynthesis ◽

Hydroxyglutaric Acid

ABSTRACT Two putative malate dehydrogenase genes, MJ1425 and MJ0490, fromMethanococcus jannaschii and one from Methanothermus fervidus were cloned and overexpressed in Escherichia coli, and their gene products were tested for the ability to catalyze pyridine nucleotide-dependent oxidation and reduction reactions of the following α-hydroxy–α-keto acid pairs: (S)-sulfolactic acid and sulfopyruvic acid; (S)-α-hydroxyglutaric acid and α-ketoglutaric acid; (S)-lactic acid and pyruvic acid; and 1-hydroxy-1,3,4,6-hexanetetracarboxylic acid and 1-oxo-1,3,4,6-hexanetetracarboxylic acid. Each of these reactions is involved in the formation of coenzyme M, methanopterin, coenzyme F420, and methanofuran, respectively. Both the MJ1425-encoded enzyme and the MJ0490-encoded enzyme were found to function to different degrees as malate dehydrogenases, reducing oxalacetate to (S)-malate using either NADH or NADPH as a reductant. Both enzymes were found to use either NADH or NADPH to reduce sulfopyruvate to (S)-sulfolactate, but theV max/Km value for the reduction of sulfopyruvate by NADH using the MJ1425-encoded enzyme was 20 times greater than any other combination of enzymes and pyridine nucleotides. Both the M. fervidus and the MJ1425-encoded enzyme catalyzed the NAD+-dependent oxidation of (S)-sulfolactate to sulfopyruvate. The MJ1425-encoded enzyme also catalyzed the NADH-dependent reduction of α-ketoglutaric acid to (S)-hydroxyglutaric acid, a component of methanopterin. Neither of the enzymes reduced pyruvate to (S)-lactate, a component of coenzyme F420. Only the MJ1425-encoded enzyme was found to reduce 1-oxo-1,3,4,6-hexanetetracarboxylic acid, and this reduction occurred only to a small extent and produced an isomer of 1-hydroxy-1,3,4,6-hexanetetracarboxylic acid that is not involved in the biosynthesis of methanofuran c. We conclude that the MJ1425-encoded enzyme is likely to be involved in the biosynthesis of both coenzyme M and methanopterin.

Download Full-text

Efficient Synthesis of a New Pipecolic Acid Analogue (I) with a Bicyclic Structure.

ChemInform ◽

10.1002/chin.200704144 ◽

2007 ◽

Vol 38 (4) ◽

Author(s):

Diego Casabona ◽

Carlos Cativiela

Keyword(s):

Pipecolic Acid ◽

Efficient Synthesis ◽

Bicyclic Structure ◽

Acid Analogue

Download Full-text

C14O2 ASSIMILATION IN LILIUM REGALE WITH REFERENCE TO γ-METHYLENEGLUTAMIC ACID

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o56-053 ◽

1956 ◽

Vol 34 (3) ◽

pp. 502-510 ◽

Cited By ~ 8

Author(s):

Margaret E. Wickson ◽

G. H. N. Towers

Keyword(s):

Carbon Dioxide ◽

Atmospheric Carbon Dioxide ◽

Keto Acid ◽

Lilium Regale ◽

Acid Analogue ◽

Atmospheric Carbon

It was found that γ-methyleneglutamic acid, γ-methylglutamic acid, and their keto-acid analogues are natural constituents of Lilium regale. These compounds were not present in the seed but appeared soon after germination. It was shown that, in seedlings, these compounds are not formed from atmospheric carbon dioxide either in the light or in the dark. This was shown also for excised leaves under a variety of conditions. In entire young plants a synthesis of γ-methyleneglutamic acid was demonstrated in the bulbs and roots. The keto-acid analogue was synthesized in all parts of the plant including the leaves. The results suggest that the accumulation of γ-methyleneglutamic acid in leaves is through transport from the subterranean organs of the plant where it is synthesized.

Download Full-text