149-63-3

Basic information

• Product Name: 2-oxobutanedioic acid
• Synonyms: 2-OXOBUTANEDIOIC ACID;oxaloacetate(2-)
• CAS NO: 149-63-3
• Molecular Formula: C₄H₂O₅
• Molecular Weight: 132.07
• Mol File: 149-63-3.mol
• Article Data: 12

Chemical Properties

• Appearance: /
• CAS DataBase Reference: 2-oxobutanedioic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 2-oxobutanedioic acid(149-63-3)
• EPA Substance Registry System: 2-oxobutanedioic acid(149-63-3)

Safety Data

• Hazardous Substances Data: 149-63-3(Hazardous Substances Data)

Usage

Definition

ChEBI: A C4-dicarboxylate resuting from deprotonation of both carboxy groups of oxaloacetic acid.

Upstream product

• 64-15-3 α-ketoglutarate 
• 68-04-2 sodium citrate 
• 85-61-0 coenzyme A 
• 67533-07-7 phosphoenolpyruvate trianion 
• 298-14-6 potassium hydrogencarbonate 
• 149-61-1 malate 
• 60047-54-3 oxalacetate dianion, hydrate form 
• 7314-09-2 oxalacetate dianion, enol form 
• 124-38-9 carbon dioxide 
• 118890-91-8 enolpyruvate 
• 73-22-3 L-Tryptophan 
• 149-61-1 (S)-malate dicarboxylate 

Downstream Products

• 1218774-52-7 C₁₈H₂₁O₈^(1-)*Na⁽¹⁺⁾ 
• 149-61-1 malate 
• 617-48-1 malic acid 

Relevant articles and documents

Application of Marcus Theory to Metal Ion Catalyzed Group Transfer Reactions

-

Increasing the conformational entropy of the Ω-loop lid domain in phosphoenolpyruvate carboxykinase impairs catalysis and decreases catalytic fidelity

Many studies have shown that the dynamic motions of individual protein segments can play an important role in enzyme function. Recent structural studies of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) demonstrate that PEPCK contains a 10-residue Ω-loop domain that acts as an active site lid. On the basis of these structural studies, we have previously proposed a model for the mechanism of PEPCK catalysis in which the conformation of this mobile lid domain is energetically coupled to ligand binding, resulting in the closed conformation of the lid, necessary for correct substrate positioning, becoming more energetically favorable as ligands associate with the enzyme. Here we test this model by introducing a point mutation (A467G) into the center of the Ω-loop lid that is designed to increase the entropic penalty for lid closure. Structural and kinetic characterization of this mutant enzyme demonstrates that the mutation has decreased the favorability of the enzyme adapting the closed lid conformation. As a consequence of this shift in the equilibrium defining the conformation of the active site lid, the enzymes ability to stabilize the reaction intermediate is weakened, resulting in catalytic defect. This stabilization is initially surprising, as the lid domain makes no direct contacts with the enolate intermediate formed during the reaction. Furthermore, during the conversion of OAA to PEP, the destabilization of the lid-closed conformation results in the reaction becoming decoupled as the enolate intermediate is protonated rather than phosphorylated, resulting in the formation of pyruvate. Taken together, the structural and kinetic characterization of A467G-PEPCK supports our model of the role of the active site lid in catalytic function and demonstrates that the shift in the lowest-energy conformation between open and closed lid states is a function of the free energy available to the enzyme through ligand binding and the entropic penalty for ordering of the 10-residue Ω-loop lid domain.

Structural and kinetic characterization of 4-hydroxy-4-methyl-2- oxoglutarate/4-carboxy-4-hydroxy-2-oxoadipate aldolase, a protocatechuate degradation enzyme evolutionarily convergent with the HpaI and DmpG pyruvate aldolases

4-Hydroxy-4-methyl-2-oxoglutarate/4-carboxy-4-hydroxy-2-oxoadipate (HMG/CHA) aldolase from Pseudomonas putida F1 catalyzes the last step of the bacterial protocatechuate 4,5-cleavage pathway. The preferred substrates of the enzyme are 2-keto-4-hydroxy acids with a 4-carboxylate substitution. The enzyme also exhibits oxaloacetate decarboxylation and pyruvate α-proton exchange activity. Sodium oxalate is a competitive inhibitor of the aldolase reaction. The pH dependence of kcat/Km and kcat for the enzyme is consistent with a single deprotonation with pKa values of 8.0 ± 0.1 and 7.0 ± 0.1 for free enzyme and enzyme substrate complex, respectively. The 1.8 A x-ray structure shows a four-layered α-β-β-α sandwich structure with the active site at the interface of two adjacent subunits of a hexamer; this fold resembles the RNase E inhibitor, RraA, but is novel for an aldolase. The catalytic site contains a magnesium ion ligated by Asp-124 as well as three water molecules bound by Asp-102 and Glu-199′. A pyruvate molecule binds the magnesium ion through both carboxylate and keto oxygen atoms, completing the octahedral geometry. The carbonyl oxygen also forms hydrogen bonds with the guanadinium group of Arg-123, which site-directed mutagenesis confirms is essential for catalysis. A mechanism for HMG/CHA aldolase is proposed on the basis of the structure, kinetics, and previously established features of other aldolase mechanisms.

Dehydration and Enolization Rates of Oxalacetate: Catalysis by Tertiary Amines

The hydration/dehydration and tautomerization rates of oxalacetate are subject to acid and base catalysis.H2O and OH- are much more effective for the former process than for the latter, but the opposite holds for tertiary amine catalysis.In buffers comprised of oxyanion bases or unsaturated amines, dehydration is significantly faster than tautomerization and remains so as the buffer concentration is varied.In dilute tertiary amine buffers dehydration rates are also faster, but as the buffer concentration increases, tautomerization rates increase rapidly and eventually surpass those for hydration/dehydration.It is this rate crossover which led earlier workers (ref 9) to propose a carbinolamine mechanism for a tertiary amine-catalyzed tautomerization.After the rate crossover is taken into account, enolization is found to show linear rate-buffer concentration behavior with tertiary amines, vitiating the prime evidence cited for the carbinolamine mechanism.However, tertiary amine catalysis likely operates differently in the tautomerization and dehydration reactions.

Direct evidence that an extended hydrogen-bonding network influences activation of pyridoxal 5'-phosphate in aspartate aminotransferase

Pyridoxal 5'-phosphate (PLP) is a fundamental, multifunctional enzyme cofactor used to catalyze a wide variety of chemical reactions involved in amino acid metabolism. PLP-dependent enzymes optimize specific chemical reactions by modulating the electronic states of PLP through distinct active site environments. In aspartate aminotransferase (AAT), an extended hydrogen bond network is coupled to the pyridinyl nitrogen of the PLP, influencing the electrophilicity of the cofactor. This network, which involves residues Asp-222, His-143, Thr-139, His-189, and structural waters, is located at the edge of PLP opposite the reactive Schiff base. We demonstrate that this hydrogen bond network directly influences the protonation state of the pyridine nitrogen of PLP, which affects the rates of catalysis. We analyzed perturbations caused by single-and double-mutant variants using steady-state kinetics, high resolution X-ray crystallography, and quantum chemical calculations. Protonation of the pyridinyl nitrogen to form a pyridinium cation induces electronic delocalization in the PLP, which correlates with the enhancement in catalytic rate in AAT. Thus, PLP activation is controlled by the proximity of the pyridinyl nitrogen to the hydrogen bond microenvironment. Quantum chemical calculations indicate that Asp-222, which is directly coupled to the pyridinyl nitrogen, increases the pKa of the pyridine nitrogen and stabilizes the pyridinium cation. His-143 and His-189 also increase the pKa of the pyridine nitrogen but, more significantly, influence the position of the proton that resides between Asp-222 and the pyridinyl nitrogen. These findings indicate that the second shell residues directly enhance the rate of catalysis in AAT.

Caged CO2 for the Direct Observation of CO2-Consuming Reactions

CO2-consuming reactions, in particular carboxylations, play important roles in technical processes and in nature. Their kinetic behavior and the reaction mechanisms of carboxylating enzymes are difficult to study because CO2 is inconvenient to handle as a gas, exists in equilibrium with bicarbonate in aqueous solution, and typically yields products that show no significant spectroscopic differences from the reactants in the UV/Vis range. Here we demonstrate the utility of 3-nitrophenylacetic acid and related compounds (caged CO2) in conjunction with infrared spectroscopy as widely applicable tools for the investigation of such reactions, permitting convenient measurement of the kinetics of CO2 consumption. The use of isotopically labeled caged CO2 provides a tool for the assignment of infrared absorption bands, thus aiding insight into reaction intermediates and mechanisms.