Metabolism of 1-aminoethylphosphinate generates acetylphosphinate, a potent inhibitor of pyruvate dehydrogenase

The alanine analogue 1-aminoethylphosphinate [H3C-CH(NH2)-PO2H2] effectively inhibited anthocyanin synthesis in buckwheat hypocotyls and caused an increase in the concentrations of alanine and alanine-derived metabolites. Aminotransferase inhibitors partially alleviated the effects of the analogue. 1-Aminoethylphosphinate did not affect the growth of Klebsiella pneumoniae under anaerobic conditions, but under aerobic conditions it inhibited growth and caused the massive excretion of pyruvate. The analogue inhibited the pyruvate dehydrogenase complex in vitro in the presence of an aminotransferase activity. The transamination product of 1-aminoethylphosphinate, acetylphosphinate (H3C-CO-PO2H2), was found to inhibit the pyruvate dehydrogenase complex in a time-dependent reaction that followed first-order and saturation kinetics and required the presence of thiamin pyrophosphate.

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Inhibition of pyruvate dehydrogenase complex by moniliformin

Biochemical Journal ◽

10.1042/bj2330719 ◽

1986 ◽

Vol 233 (3) ◽

pp. 719-723 ◽

Cited By ~ 39

Author(s):

P S Gathercole ◽

P G Thiel ◽

J H S Hofmeyr

Keyword(s):

Pyruvate Dehydrogenase ◽

Inhibitory Action ◽

Pyruvate Dehydrogenase Complex ◽

Time Dependent ◽

Enzyme Complex ◽

First Order ◽

Saturation Kinetics ◽

Thiamin Pyrophosphate ◽

Inhibition Reaction ◽

Dehydrogenase Complex

The mechanism for the inhibition of pyruvate dehydrogenase complex from bovine heart by moniliformin was investigated. Thiamin pyrophosphate proved to be necessary for the inhibitory action of moniliformin. The inhibition reaction was shown to be time-dependent and to follow first-order and saturation kinetics. Pyruvate protected the pyruvate dehydrogenase complex against moniliformin inactivation. Extensive dialysis of the moniliformin-inactivated complex only partially reversed inactivation. Moniliformin seems to act by inhibition of the pyruvate dehydrogenase component of the enzyme complex and not by acting on the dihydrolipoamide transacetylase or dehydrogenase components, as shown by monitoring the effect of moniliformin on each component individually. On the basis of these results, a suicide inactivator mechanism for moniliformin on pyruvate dehydrogenase is proposed.

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On the Specificity of the Herbicide Chlorsulfuron in Intact Spinach Chloroplasts

Zeitschrift für Naturforschung C ◽

10.1515/znc-1985-11-1229 ◽

1985 ◽

Vol 40 (11-12) ◽

pp. 917-918 ◽

Cited By ~ 3

Author(s):

Uwe Homeyer ◽

D. Schulze-Siebert ◽

G. Schultz

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Fatty Acid Synthesis ◽

Pyruvate Dehydrogenase ◽

Pyruvate Dehydrogenase Complex ◽

Acid Synthesis ◽

Spinach Chloroplasts ◽

Transamination Reaction ◽

Dehydrogenase Complex

Abstract In vitro incubation of intact spinach chloroplasts with 1 mᴍ Pyruvate was used to study the specificity of action of the herbicide Chlorsulfuron on the synthesis of valine, alanine and fatty acids. As a result, increasing concentrations of the herbicide strongly inhibited valine synthesis while fatty acid synthesis via pyruvate dehydrogenase complex (PDC) and alanine formation by transamination reaction was promoted.

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Fluoropyruvate: A potent inhibitor of the bacterial and the mammalian pyruvate dehydrogenase complex

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(80)90814-1 ◽

1980 ◽

Vol 95 (2) ◽

pp. 513-519 ◽

Cited By ~ 12

Author(s):

H. Bisswanger

Keyword(s):

Pyruvate Dehydrogenase ◽

Potent Inhibitor ◽

Pyruvate Dehydrogenase Complex ◽

Dehydrogenase Complex

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Regulation of pyruvate dehydrogenase activity through phosphorylation at multiple sites

Biochemical Journal ◽

10.1042/bj3580069 ◽

2001 ◽

Vol 358 (1) ◽

pp. 69-77 ◽

Cited By ~ 98

Author(s):

Elena KOLOBOVA ◽

Alina TUGANOVA ◽

Igor BOULATNIKOV ◽

Kirill M. POPOV

Keyword(s):

Pyruvate Dehydrogenase ◽

Pyruvate Dehydrogenase Complex ◽

Phosphorylation Site ◽

Enzymic Activity ◽

Mammalian Tissues ◽

Activity State ◽

The Individual ◽

Pyruvate Dehydrogenase Phosphatase ◽

Thiamin Pyrophosphate ◽

Dehydrogenase Complex

The enzymic activity of the mammalian pyruvate dehydrogenase complex is regulated by the phosphorylation of three serine residues (sites 1, 2 and 3) located on the E1 component of the complex. Here we report that the four isoenzymes of protein kinase responsible for the phosphorylation and inactivation of pyruvate dehydrogenase (PDK1, PDK2, PDK3 and PDK4) differ in their abilities to phosphorylate the enzyme. PDK1 can phosphorylate all three sites, whereas PDK2, PDK3 and PDK4 each phosphorylate only site 1 and site 2. Although PDK2 phosphorylates site 1 and 2, it incorporates less phosphate in site 2 than PDK3 or PDK4. As a result, the amount of phosphate incorporated by each isoenzyme decreases in the order PDK1>PDK3PDK4>PDK2. Significantly, binding of the coenzyme thiamin pyrophosphate to pyruvate dehydrogenase alters the rates and stoichiometries of phosphorylation of the individual sites. First, the rate of phosphorylation of site 1 by all isoenzymes of kinase is decreased. Secondly, thiamin pyrophosphate markedly decreases the amount of phosphate that PDK1 incorporates in sites 2 and 3 and that PDK2 incorporates in site 2. In contrast, the coenzyme does not significantly affect the total amount of phosphate incorporated in site 2 by PDK3 and PDK4, but instead decreases the rate of phosphorylation of this site. Furthermore, pyruvate dehydrogenase complex phosphorylated by the individual isoenzymes of kinase is reactivated at different rates by pyruvate dehydrogenase phosphatase. Both isoenzymes of phosphatase (PDP1 and PDP2) readily reactivate the complex phosphorylated by PDK2. When pyruvate dehydrogenase is phosphorylated by other isoenzymes, the rates of reactivation decrease in the order PDK4PDK3> PDK1. Taken together, results reported here strongly suggest that the major determinants of the activity state of pyruvate dehydrogenase in mammalian tissues include the phosphorylation site specificity of isoenzymes of kinase in addition to the absolute amounts of kinase and phosphatase protein expressed in mitochondria.

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In vitro synthesis and processing of components of the Ascaris suum pyruvate dehydrogenase complex

Molecular and Biochemical Parasitology ◽

10.1016/0166-6851(88)90113-2 ◽

1988 ◽

Vol 29 (1) ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

V RUFF ◽

S DESAI ◽

E DUBRUL ◽

R KOMUNIECKI

Keyword(s):

Pyruvate Dehydrogenase ◽

Ascaris Suum ◽

Pyruvate Dehydrogenase Complex ◽

In Vitro Synthesis ◽

Synthesis And Processing ◽

Dehydrogenase Complex

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Expression and lipoylation in Escherichia coli of the inner lipoyl domain of the E2 component of the human pyruvate dehydrogenase complex

Biochemical Journal ◽

10.1042/bj2890081 ◽

1993 ◽

Vol 289 (1) ◽

pp. 81-85 ◽

Cited By ~ 35

Author(s):

J Quinn ◽

A G Diamond ◽

A K Masters ◽

D E Brookfield ◽

N G Wallis ◽

...

Keyword(s):

Escherichia Coli ◽

Pyruvate Dehydrogenase ◽

Pyruvate Dehydrogenase Complex ◽

Structural Studies ◽

Gene Encoding ◽

E Coli ◽

Inner Lipoyl Domain ◽

Dehydrogenase Complex ◽

Lipoyl Domain

The dihydrolipoamide acetyltransferase subunit (E2p) of mammalian pyruvate dehydrogenase complex has two highly conserved lipoyl domains each modified with a lipoyl cofactor bound in amide linkage to a specific lysine residue. A sub-gene encoding the inner lipoyl domain of human E2p has been over-expressed in Escherichia coli. Two forms of the domain have been purified, corresponding to lipoylated and non-lipoylated species. The apo-domain can be lipoylated in vitro with partially purified E. coli lipoate protein ligase, and the lipoylated domain can be reductively acetylated by human E1p (pyruvate dehydrogenase). Availability of the two forms will now allow detailed biochemical and structural studies of the human lipoyl domains.

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