Publications

• Carboligase activity of alpha-ketoglutarate dehydrogenase.

  Schlossberg M.A., Bloom R.J., Richert D.A., Westerfeld W.W.

  Biochemistry 9:1148-1153(1970) [PubMed] [EuropePMC]

• The synergistic decarboxylation of glyoxylate and 2-oxoglutarate by an enzyme system from pig-liver mitochondria.

  Stewart P.R., Quayle J.R.

  1. An enzyme system that catalyses a synergistic decarboxylation of glyoxylate and 2-oxoglutarate has been purified from pig-liver mitochondria. 2. The purified system is specific for glyoxylate and 2-oxoglutarate as substrates, although in earlier stages of purification glycine and l-glutamate ar ... >> More

  1. An enzyme system that catalyses a synergistic decarboxylation of glyoxylate and 2-oxoglutarate has been purified from pig-liver mitochondria. 2. The purified system is specific for glyoxylate and 2-oxoglutarate as substrates, although in earlier stages of purification glycine and l-glutamate are also active. 3. The reaction is inhibited strongly by EDTA and N-ethylmaleimide. Substrate analogues, present at concentrations equimolar with respect to the substrates, are not effective as inhibitors. 4. The reaction proceeds in the absence of added cofactors. Magnesium chloride, mercaptoethanol and sucrose stimulate the reaction, and stabilize the activity of the enzyme. 5. The pH optimum of the reaction is 7.0. The K(m) values of glyoxylate and 2-oxoglutarate, at saturating concentration of the corresponding co-substrate, are 16mm and 3.6mm respectively. 6. Isotopic work with specifically labelled [(14)C]glyoxylate and 2-oxo[(14)C]-glutarate suggests that the enzyme system catalyses an initial condensation of glyoxylate and 2-oxoglutarate that results in, or leads to, release of C-1 of both substrates as carbon dioxide. C-2 of glyoxylate and C-5 of 2-oxoglutarate do not appear as carbon dioxide. 7. The stoicheiometry of the reaction is complex. During the initial stages of the reaction, more carbon dioxide is recovered from 2-oxoglutarate than from glyoxylate. Subsequently, there is a disproportionate increase with time of carbon dioxide evolution from the carboxyl group of glyoxylate. The excess of decarboxylation of glyoxylate over 2-oxogluturate is further increased by treatment of reaction products with acid. << Less

  Biochem J 102:885-897(1967) [PubMed] [EuropePMC]

• Purification, general properties and two other catalytic activities of -ketoglutarate:glyoxylate carboligase of Mycobacterium Phlei.

  Yamasaki H., Moriyama T.

  Biochim Biophys Acta 242:637-647(1971) [PubMed] [EuropePMC]

• Functional plasticity and allosteric regulation of alpha-ketoglutarate decarboxylase in central mycobacterial metabolism.

  Wagner T., Bellinzoni M., Wehenkel A., O'Hare H.M., Alzari P.M.

  The α-ketoglutarate dehydrogenase (KDH) complex is a major regulatory point of aerobic energy metabolism. Mycobacterium tuberculosis was reported to lack KDH activity, and the putative KDH E1o component, α-ketoglutarate decarboxylase (KGD), was instead assigned as a decarboxylase or carboligase. H ... >> More

  The α-ketoglutarate dehydrogenase (KDH) complex is a major regulatory point of aerobic energy metabolism. Mycobacterium tuberculosis was reported to lack KDH activity, and the putative KDH E1o component, α-ketoglutarate decarboxylase (KGD), was instead assigned as a decarboxylase or carboligase. Here, we show that this protein does in fact sustain KDH activity, as well as the additional two reactions, and these multifunctional properties are shared by the Escherichia coli homolog, SucA. We also show that the mycobacterial enzyme is finely regulated by an additional acyltransferase-like domain and by the action of acetyl-CoA, a powerful allosteric activator able to enhance the concerted protein motions observed during catalysis. Our results uncover the functional plasticity of a crucial node in bacterial metabolism, which may be important for M. tuberculosis during host infection. << Less

  Chem. Biol. 18:1011-1020(2011) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Isolation and identification of 5-hydroxy-4-ketovaleric acid as a product of alpha-ketoglutarate: glyoxylate carboligase.

  Schlossberg M.A., Richert D.A., Bloom R.J., Westerfeld W.W.

  Biochemistry 7:333-337(1968) [PubMed] [EuropePMC]