Biomaterial Database

Nicotinic acid metabolism: stereochemical course of the (2R,3S)-2,3-dimethylmalate lyase reaction. 1982

G Löhlein, and H Eggerer

1. The enantiomers of chiral propionate were prepared by cleavage of (2R,3S)-2,3-dimethylmalate and of (2R,3S)-[3-3H1]-2,3-dimethylmalate with the corresponding lyase in tritiated and in ordinary water, respectively. 2. Using commercially available citrate lyase, an enzymic method was elaborated for the formation of (3S)-citryl-CoA from acetyl-CoA and citrate in a preparative scale (mumol). The product was used in the presence of propionate (or acetate) and partially inactivated citrate lyase to prepare propionyl-CoA (or acetyl-CoA). The method was applied to the chiral propionates as well as symmetrically labelled [2-3H2]propionate and is suggested to be superior to others for the preparation of propionyl-CoA (or acetyl-CoA) from mumol of radioactively labelled acid. 3. On configurational determination with propionyl-CoA carboxylase the [2-3H12]propionyl-CoA derived from unlabelled dimethylmalate retained nearly all of the tritium label, whereas that derived from the labelled substrate lost the tritium label completely; [2-3H2]propionyl-CoA lost 50% of its label. 4. It was concluded from these results that the cleavage reaction on (2R,3S)-2,3-dimethylmalate lyase proceeds with inversion of configuration at C-3 of the substrate which becomes C-2 of propionate.

UI	MeSH Term	Description	Entries
D007652	Oxo-Acid-Lyases	Enzymes that catalyze the cleavage of a carbon-carbon bond of a 3-hydroxy acid. (Dorland, 28th ed) EC 4.1.3.	Ketoacid-Lyases,Ketoacid Lyases,Oxo Acid Lyases
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009525	Niacin	A water-soluble vitamin of the B complex occurring in various animal and plant tissues. It is required by the body for the formation of coenzymes NAD and NADP. It has PELLAGRA-curative, vasodilating, and antilipemic properties.	Nicotinic Acid,3-Pyridinecarboxylic Acid,Enduracin,Induracin,Lithium Nicotinate,Niacin Aluminum Salt,Niacin Ammonium Salt,Niacin Calcium Salt,Niacin Cobalt (2+) Salt,Niacin Copper (2+) Salt,Niacin Hydrochloride,Niacin Iron (2+) Salt,Niacin Lithium Salt,Niacin Lithium Salt, Hemihydrate,Niacin Magnesium Salt,Niacin Manganese (2+) Salt,Niacin Potassium Salt,Niacin Sodium Salt,Niacin Tartrate,Niacin Tosylate,Niacin Zinc Salt,Nicamin,Nico-400,Nicobid,Nicocap,Nicolar,Nicotinate,Wampocap,3 Pyridinecarboxylic Acid,Aluminum Salt, Niacin,Hydrochloride, Niacin,Nico 400,Nico400,Nicotinate, Lithium,Potassium Salt, Niacin,Sodium Salt, Niacin,Tartrate, Niacin,Tosylate, Niacin
D003013	Clostridium	A genus of motile or nonmotile gram-positive bacteria of the family Clostridiaceae. Many species have been identified with some being pathogenic. They occur in water, soil, and in the intestinal tract of humans and lower animals.
D013237	Stereoisomerism	The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Molecular Stereochemistry,Stereoisomers,Stereochemistry, Molecular,Stereoisomer
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities