undecylprodigiosin and prodiginine

Prodiginines are bacterial red polypyrrole pigments and multifaceted secondary metabolites. These agents have anti-proliferative, immunosuppressive, antimicrobial, and anticancer effects. Recent analysis revealed that prodigiosin hypersensitizes Serratia marcescens to gamma radiation. In the present study, we report the cytotoxicity and genotoxicity properties of undecylprodigiosin and butylcycloheptylprodigiosin in the presence and absence of radiation through the MTT and alkaline comet experiments.. Findings demonstrated that undecylprodigiosin was at least a fivefold more cytotoxic at low radiation doses (1 and 3 Gy) on both MCF7 and HDF lines rather than in the absence or high radiation doses (5 Gy) (P value < 0.05). Although butylcycloheptylprodigiosin toxicity on MCF7 and HDF was dose-dependent, it was not influenced by any radiation doses (P value > 0.05). Comet findings confirmed that these compounds' genotoxicity is only dose-dependent. Radiation had no significant effects on DNA damage on any of the cells (P value > 0.05).. In general, it can be concluded that the prodiginines are cytotoxic agents that act as a double-edged sword, radiosensitizers and radio-protective, respectively at low and high radiation doses in cancer treatment process. As the results they could be used in antitumor therapies very soon.

Topics: Anti-Infective Agents; Antineoplastic Agents; Cell Line; DNA Damage; Humans; Immunosuppressive Agents; MCF-7 Cells; Neoplasms; Photosensitizing Agents; Prodigiosin

Gram-positive

Topics: Anti-Bacterial Agents; Base Composition; Base Sequence; DNA Transposable Elements; Gene Expression Regulation, Bacterial; Gene Library; Mutagenesis, Insertional; Prodigiosin; Secondary Metabolism; Streptomyces coelicolor; Transposases

The last step of proline biosynthesis is typically catalysed by the enzyme Δ(1)-pyrroline-5-carboxylate reductase, encoded by the proC gene. Complete genome sequencing of Streptomyces coelicolor, a soil-dwelling Gram-positive bacterium that uses proline as a precursor for synthesis of prodiginine, revealed a single copy of this gene. Unexpectedly, disruption of this proC homologue (Sco3337) in S. coelicolor M145 yielded a prototrophic strain, yet the reductase activity of Sco3337 was confirmed by complementation of an Escherichia coli proC mutant. Multicopy proC within different genetic contexts elicited a transient production of prodiginines, which showed differential production kinetics of the two most common forms of this natural product produced by S. coelicolor, i.e. streptorubin B (cyclic) and undecylprodigiosin (linear). The metabolic and evolutionary implications of these observations are discussed.

Topics: Biological Evolution; delta-1-Pyrroline-5-Carboxylate Reductase; Gene Dosage; Genes, Bacterial; Mutation; Prodigiosin; Proline; Pyrroline Carboxylate Reductases; Streptomyces coelicolor

Reports of anticancer and immunosuppressive properties have spurred recent interest in the bacterially produced prodiginines. We use electrospray tandem mass spectrometry (ES-MS/MS) to investigate prodigiosin, undecylprodiginine, and streptorubin B (butyl-meta-cycloheptylprodiginine) and to explore their fragmentation pathways to explain the unusual methyl radical loss and consecutive fragment ions that dominate low-energy collision-induced dissociation (CID) mass spectra. The competition between the formation of even-electron ions and radical ions is examined in detail. Theoretical calculations are used to optimize the structures and calculate the energies of both reactants and products using the Gaussian 03 program. Results indicate that protonation occurs on the nitrogen atom that initially held no hydrogen, thus allowing formation of a pseudo-seven-membered ring that constitutes the most stable ground state [M + H](+) structure. From this precursor, experimental data show that methyl radical loss has the lowest apparent threshold but, alternatively, even-electron fragment ions can be formed by loss of a methanol molecule. Computational modeling indicates that methyl radical loss is the more endothermic process in this competition, but the lower apparent threshold associated with methyl radical loss points to a lower kinetic barrier. Additionally, this characteristic and unusual loss of methyl radical (in combination with weaker methanol loss) from each prodiginine is useful for performing constant neutral loss scans to quickly and efficiently identify all prodiginines in a complex biological mixture without any clean-up or purification. The feasibility of this approach has been proven through the identification of a new, low-abundance prodigiosin analog arising from Hahella chejuensis.

Topics: Anti-Bacterial Agents; Electrons; Ions; Molecular Structure; Pigments, Biological; Prodigiosin; Spectrometry, Mass, Electrospray Ionization; Thermodynamics

The red gene cluster of Streptomyces coelicolor directs production of undecylprodiginine. Here we report that this gene cluster also directs production of streptorubin B and show that 2-undecylpyrrole (UP) is an intermediate in the biosynthesis of undecylprodiginine and streptorubin B. The redPQRKL genes are involved in UP biosynthesis. RedL and RedK are proposed to generate UP from dodecanoic acid or a derivative. A redK(-) mutant produces a hydroxylated undecylprodiginine derivative, whereas redL(-) and redK(-) mutants require addition of chemically synthesized UP for production of undecylprodiginine and streptorubin B. Fatty acid biosynthetic enzymes can provide dodecanoic acid, but efficient and selective prodiginine biosynthesis requires RedPQR. Deletion of redP, redQ, or redR leads to an 80%-95% decrease in production of undecylprodiginine and an array of prodiginine analogs with varying alkyl chains. In a redR(-) mutant, the ratio of these can be altered in a logical manner by feeding various fatty acids.

Topics: Biosynthetic Pathways; Multigene Family; Prodigiosin; Pyrroles; Sequence Deletion; Streptomyces coelicolor