2,4-diaminovaleric acid: an intermediate in the anaerobic oxidation of ornithine by Clostridium sticklandii.

The oxidation of ornithine in the presence of proline by crude extracts of Clostridium sticklandii cells was stimulated by nicotinamide adenine dinucleotide, coenzyme A, alpha-ketoglutarate, dimethylbenzimidazolyl cobamide (DBC) coenzyme, MgCl(2), and adenosine diphosphate. Deletion of various cofactors resulted in the accumulation of a new dibasic amino acid which was identified as 2,4-diaminovaleric acid. Both the oxidation of ornithine to alanine and acetate and the conversion of ornithine to 2,4-diaminovaleric acid were stimulated by addition of DBC coenzyme, and both were inhibited by intrinsic factor, an inhibitor of cobamide coenzyme-dependent reactions. This inhibition was reversed by addition of DBC coenzyme. However, the oxidation of 2,4-diaminovaleric acid was insensitive to added intrinsic factor. The data indicate that 2,4-diaminovaleric acid represents the first intermediate in the oxidation of ornithine by C. sticklandii.