collismycin-a has been researched along with picolinic-acid* in 2 studies
2 other study(ies) available for collismycin-a and picolinic-acid
| Article | Year |
|---|---|
Generation by mutasynthesis of potential neuroprotectant derivatives of the bipyridyl collismycin A.
Collismycin A is a member of the 2,2'-bipyridyl family of natural products and structurally belongs to the hybrid polyketides-nonribosomal peptides. A gene coding for a lysine 2-aminotransferase of Streptomyces sp. CS40 (collismycin A producer) was inactivated by gene replacement. The mutant was unable of synthesizing collismycin A but it recovered this capability when picolinic acid was added to the culture medium. By feeding different picolinic acid analogs to this mutant, two new collismycin A derivatives were obtained with a methyl group at the 4 and 6 position of the first pyridine ring of collismycin A, respectively. The two compounds showed effective neuroprotective action against an oxidative stress inducer in a zebra fish model, one of them showing higher neuroprotectant activity than that of collismycin A and that of the control lipoic acid. Topics: 2,2'-Dipyridyl; Animals; Larva; Models, Animal; Neuroprotective Agents; Oxidative Stress; Picolinic Acids; Streptomyces; Transaminases; Zebrafish | 2013 |
Elucidating the biosynthetic pathway for the polyketide-nonribosomal peptide collismycin A: mechanism for formation of the 2,2'-bipyridyl ring.
The gene cluster for the bipyridyl compound collismycin was characterized from Streptomyces sp. CS40. Sequence analysis of a 46.7 kb DNA region revealed 27 open reading frames, 23 of which are involved in collismycin biosynthesis. Eight insertional inactivation mutants were generated in the sequenced region to prove its involvement in collismycin biosynthesis, define the boundaries of the cluster, functionally characterize some genes, and isolate two biosynthetic intermediates. A model for collismycin biosynthesis--which includes the conversion of lysine into picolinic acid, participation of a polyketide synthase-non-ribosomal peptide synthetase system, and some further modifications--is proposed. The biosynthetic pathway would include an unusual NRPS-mediated incorporation of a cysteine residue, possibly through a Michael addition and followed by the extension of the peptide chain by leucine incorporation and later removal by amidohydrolase. Topics: 2,2'-Dipyridyl; Amino Acid Sequence; Lysine; Molecular Sequence Data; Multigene Family; Peptide Synthases; Picolinic Acids; Streptomyces | 2012 |