1420-36-6Relevant academic research and scientific papers
Thiamine pyrophosphate stimulates acetone activation by desulfococcus biacutus as monitored by a fluorogenic ATP analogue
Gutiérrez Acosta, Olga B.,Hardt, Norman,Hacker, Stephan M.,Strittmatter, Tobias,Schink, Bernhard,Marx, Andreas
, p. 1263 - 1266 (2014)
Acetone can be degraded by aerobic and anaerobic microorganisms. Studies with the strictly anaerobic sulfate-reducing bacterium Desulfococcus biacutus indicate that acetone degradation by these bacteria starts with an ATP-dependent carbonylation reaction leading to acetoacetaldehyde as the first reaction product. The reaction represents the second example of a carbonylation reaction in the biochemistry of strictly anaerobic bacteria, but the exact mechanism and dependence on cofactors are still unclear. Here, we use a novel fluorogenic ATP analogue to investigate its mechanism. We find that thiamine pyrophosphate is a cofactor of this ATP-dependent reaction. The products of ATP cleavage are AMP and pyrophosphate, providing first insights into the reaction mechanism by indicating that the reaction proceeds without intermediate formation of acetone enol phosphate.
Unprecedented acetoacetyl-coenzyme A synthesizing enzyme of the thiolase superfamily involved in the mevalonate pathway
Okamura, Eiji,Tomita, Takeo,Sawa, Ryuichi,Nishiyama, Makoto,Kuzuyama, Tomohisa
, p. 11265 - 11270 (2010)
Acetoacetyl-CoA is the precursor of 3-hydroxy-3-methylglutaryl (HMG)-CoA in the mevalonate pathway, which is essential for terpenoid backbone biosynthesis. Acetoacetyl-CoA is also the precursor of poly-β-hydroxybutyrate, a polymer belonging to the polyester class produced by microorganisms. The de novo synthesis of acetoacetyl-CoA is usually catalyzed by acetoacetyl-CoA thiolase via a thioester-dependent Claisen condensation reaction between two molecules of acetyl-CoA. Here, we report that nphT7, found in the mevalonate pathway gene cluster from a soil-isolated Streptomyces sp. strain, encodes an unusual acetoacetyl-CoA synthesizing enzyme. The recombinant enzyme overexpressed in Escherichia coli catalyzes a single condensation of acetyl-CoA and malonyl-CoA to give acetoacetyl-CoA and CoA. Replacement of malonyl-CoA with malonyl-(acyl carrier protein) resulted in loss of the condensation activity. No acetoacetyl-CoA synthesizing activity was detected through the condensation of two molecules of acetyl-CoA. Based on these properties of NphT7, we propose to name this unusual enzyme of the thiolase superfamily acetoacetyl-CoA synthase. Co-expression of nphT7 with the HMG-CoA synthase gene and the HMG-CoA reductase gene in a heterologous host allowed 3.5-fold higher production of mevalonate than when only the HMG-CoA synthase and HMG-CoA reductase genes were expressed. This result suggests that nphT7 can be used to significantly increase the concentration of acetoacetyl-CoA in cells, eventually leading to the production of useful terpenoids and poly-β-hydroxybutyrate.
Characterization of a highly thermostable ss-hydroxybutyryl CoA dehydrogenase from Clostridium acetobutylicum ATCC 824
Sommer, Bettina,Garbe, Daniel,Schrepfer, Patrick,Brueck, Thomas
, p. 138 - 144 (2013)
Higher energy content and hydrophobicity make bio-based n-butanol a preferred building block for chemical and biofuels manufacturing. Butanol is obtained by Clostridium sp. based ABE fermentation process. While the ABE process is well understood, the enzyme systems involved have not been elucidated in detail. The important enzyme ss-hydroxybutyryl CoA dehydrogenase from Clostridium acetobutylicum ATCC 824 (Hbd) was purified and characterized. Surprisingly, Hbd shows extremely high temperature (T > 60 C), pH (4-11) and solvent (1-butanol, isobutanol, ethanol) stability. Hbd catalyzes acetoacetyl CoA hydration to ss-hydroxybutyryl CoA up to pH 9.5, where the reaction is reversed. Substrate (acacCoA, ss-hbCoA) and cofactor (NADH, NAD +, NADPH and NADP+) specificities were determined. We identified NAD+ as an uncompetitive inhibitor. Identification of process relevant enzymes such as Hbd is key to optimize butanol production via cellular or cell-free enzymatic systems.
Chemoenzymatic Synthesis of Acyl Coenzyme A Substrates Enables in Situ Labeling of Small Molecules and Proteins
Agarwal, Vinayak,Diethelm, Stefan,Ray, Lauren,Garg, Neha,Awakawa, Takayoshi,Dorrestein, Pieter C.,Moore, Bradley S.
, p. 4452 - 4455 (2015/09/28)
A chemoenzymatic approach to generate fully functional acyl coenzyme A molecules that are then used as substrates to drive in situ acyl transfer reactions is described. Mass spectrometry based assays to verify the identity of acyl coenzyme A enzymatic products are also illustrated. The approach is responsive to a diverse array of carboxylic acids that can be elaborated to their corresponding coenzyme A thioesters, with potential applications in wide-ranging chemical biology studies that utilize acyl coenzyme A substrates.
