320-77-4Relevant articles and documents
Photocatalytic Fixation of Carbon Dioxide in Oxoglutaric Acid using Isocitrate Dehydrogenase and Cadmium Sulphide
Inoue, Hiroshi,Kubo, Yasuko,Yoneyama, Hiroshi
, p. 553 - 557 (1991)
Photocatalytic fixation of CO2 in oxoglutaric acid to yield isocitric acid was investigated with the use of isocitrate dehydrogenase as a catalyst, methyl viologen as an electron mediator and cadmium sulphide as a photocatalyst.The rate of the isocitric acid production depended on the concentration of oxoglutaric acid and methyl viologen, and the rate equation to meet these findungs was derived.The Michaelis-Menten constant determined by using this equation (Km1 and Km2) was 23.9 mmol dm-3 for the substrate and 0.030 mmol dm-3 for the mediator, suggesting that the electron transfer between isocitrate dehydrogenase and the substrate is the rate-determining step.
Cyanide as a primordial reductant enables a protometabolic reductive glyoxylate pathway
Krishnamurthy, Ramanarayanan,Pulletikurti, Sunil,Yadav, Mahipal,Yerabolu, Jayasudhan R.
, p. 170 - 178 (2022/02/11)
Investigation of prebiotic metabolic pathways is predominantly based on abiotically replicating the reductive citric acid cycle. While attractive from a parsimony point of view, attempts using metal/mineral-mediated reductions have produced complex mixtures with inefficient and uncontrolled reactions. Here we show that cyanide acts as a mild and efficient reducing agent mediating abiotic transformations of tricarboxylic acid intermediates and derivatives. The hydrolysis of the cyanide adducts followed by their decarboxylation enables the reduction of oxaloacetate to malate and of fumarate to succinate, whereas pyruvate and α-ketoglutarate themselves are not reduced. In the presence of glyoxylate, malonate and malononitrile, alternative pathways emerge that bypass the challenging reductive carboxylation steps to produce metabolic intermediates and compounds found in meteorites. These results suggest a simpler prebiotic forerunner of today’s metabolism, involving a reductive glyoxylate pathway without oxaloacetate and α-ketoglutarate—implying that the extant metabolic reductive carboxylation chemistries are an evolutionary invention mediated by complex metalloproteins. [Figure not available: see fulltext.].
Role of Methylcitric Acid Cycle in Catabolism of Amino Acids by Saccharomycopsis lipolitica
Miyakoshi, Shunichi,Enami, Kengo,Uchiyama, Hiroo,Tabuchi, Takeshi
, p. 1017 - 1022 (2007/10/02)
We examined the production of 2-methylisocitric acid, an intermediate of the constitutive methylcitric acid cycle involved in propionyl-CoA oxidation during the catabolism of different amino acids by a mutant lacking 2-methylisocitrate lyase, a key enzyme of the cycle.The acid was produced equmolarly from isoleucine within a range of amounts of the amino acid added.The amount of the acid produced also increased depending upon the amounts of valine, threonine, methionine, homoserine, and α-aminobutyric acid.However, only a little acid was produced from the 13 other amino acids tested.These results indicated that propionyl-CoA was involved in the catabolism of the first six amino acids named, but not in the other 13.Intramolecular amino acids were therefore part of metabolic turnover and the constitutive cycle functioned in the catabolism of propionyl-CoA derived from the turnover.
