Based on genome mining, a new antibacterial peptide named actinokineosin was isolated from a rare actinomycete Actinokineospora spheciospongiae. The amino acid sequence of the C‐terminus of ...actinokineosin was established by TOF‐MS/MS experiments. The amino acid sequence in the macrolactam ring was determined by TOF‐MS/MS analyses after cleavage with BNPS‐skatole and successive trypsin treatment. As a result of an antibacterial assay using a paper disk, actinokineosin showed antibacterial activity against Micrococcus luteus at a dosage of 50 μg per disk. From the genome sequence data of A. spheciospongiae, the biosynthetic gene cluster of actinokineosin was found and was indicated to consist of 10 genes. Among the genes, the gene aknA encoded the precursor of actinokineosin and the genes including aknC, aknB1 and aknB2 were proposed as modification enzymes to give mature actinokineosin.
Significance and Impact of the Study
Genome mining is a powerful tool to find new bioactive compounds from the genome database. In this report, we succeeded in isolation and structure determination of a new antibacterial peptide named actinokineosin based on genome mining.
Significance and Impact of the Study: Genome mining is a powerful tool to find new bioactive compounds from the genome database. In this report, we succeeded in isolation and structure determination of a new antibacterial peptide named actinokineosin based on genome mining.
Adamantyl-containing 1,3-disubstituted ureas, bisureas, and biscarbamates containing different spacers between the ureylene or the carbamate groups and the adamantyl radical were synthesized. Their ...inhibitory activity against soluble epoxide hydrolases of mammals and humans (sEH, E.C. 3.3.2.10) was studied. The compounds were found to possess high inhibitory activity on the level of 0.8—2.7 nmol L
–1
. A relationship between the inhibitor structure and its activity was established.
Proton pump inhibitors such as omeprazole (OME) reduce the severity of gastrointestinal (GI) ulcers induced by nonsteroidal anti-inflammatory drugs (NSAIDs) but can also increase the chance of ...dysbiosis. The aim of this study was to test the hypothesis that preventive use of a soluble epoxide hydrolase inhibitor (sEHI) such as TPPU can decrease NSAID-induced ulcers by increasing anti-inflammatory epoxyeicosatrienoic acids (EETs). Dose- 10, 30, and 100 mg/kg, by mouth (PO) and time-dependent (6 and 18 hours) ulcerative effects of diclofenac sodium (DCF, an NSAID) were studied in the small intestine of Swiss Webster mice. Dose-dependent effects of TPPU (0.001-0.1 mg/kg per day for 7 days, in drinking water) were evaluated in DCF-induced intestinal toxicity and compared with OME (20 mg/kg, PO). In addition, the effect of treatment was studied on levels of Hb in blood, EETs in plasma, inflammatory markers such as myeloperoxidase (MPO) in intestinal tissue homogenates, and tissue necrosis factor-α (TNF-α) in serum. DCF dose dependently induced ulcers that were associated with both a significant (P < 0.05) loss of Hb and an increase in the level of MPO and TNF-α, with severity of ulceration highest at 18 hours. Pretreatment with TPPU dose dependently prevented ulcer formation by DCF, increased the levels of epoxy fatty acids, including EETs, and TPPU's efficacy was comparable to OME. TPPU significantly (P < 0.05) reversed the effect of DCF on the level of Hb, MPO, and TNF-α Thus sEHI might be useful in the management of NSAID-induced ulcers.
Aeruginosin 103-A was isolated from the cultured freshwater cyanobacterium Microcystis viridis (NIES-103). Its structure was elucidated to be 1 on the basis of 2D NMR data. This linear peptide ...inhibited thrombin, with an IC50 of 9.0 μg/mL.
SapB is a morphogenetic peptide that is important for aerial mycelium formation by the filamentous bacterium Streptomyces coelicolor. Production of SapB commences during aerial mycelium formation and ...depends on most of the genes known to be required for the morphogenesis of aerial hyphae. Furthermore, the application of purified SapB to mutants blocked in morphogenesis restores their capacity to form aerial hyphae. Here, we present evidence that SapB is a lantibiotic-like peptide that is derived by posttranslational modification from the product of a gene (ramS) in the four-gene ram operon, which is under the control of the regulatory gene ramR. We show that the product of another gene in the operon (ramC) contains a region that is similar to enzymes involved in the biosynthesis of lantibiotics, suggesting that it might be involved in the posttranslational processing of RamS. We conclude that SapB is derived from RamS through proteolytic cleavage and the introduction of four dehydroalanine residues and two lanthionine bridges. We provide an example of a morphogenetic role for an antibiotic-like molecule.
The potential of reducing losses due to corm rots on taro (
Colocasia esculenta cv. Bun-long) using organic farming practices was evaluated in an Andisol under rain-fed conditions during successive ...seasons between 1996 and 1998. Treatments were: (1) inorganic fertilizer plus pre-emergent herbicide (control); (2) control with additional calcium (Ca) and alfalfa pellets; (3) chicken manure with silage mulch; (4) chicken manure with wood chip mulch; (5) chicken manure with macadamia nut compost and silage mulch; and (6) solarization plus chicken manure and silage mulch. Taro corms were harvested at 7, 9, and 11 months after planting (MAP). There were no significant effects of compost, Ca+alfalfa pellets, or solarization on taro yield. Plots that included mulch produced significantly greater fresh weight corm yields and higher percentage corm dry matter, but also showed a higher incidence of corm rots compared to non-mulched plots. Mulching appeared to increase soil moisture content which promoted both growth of taro and conditions conducive to corm rot. Although yields were increased in treatments with mulch, these increases in crop value were not sufficient to cover increased costs of production.
Summary
Withstanding environmental adversity and seeking optimal conditions for reproduction are basic requirements for the survival of all organisms. Filamentous bacteria of the genus Streptomyces ...produce a remarkable cell type called the aerial hyphae that is central to its ability to meet both of these challenges. Recent advances have brought about a major shift in our understanding of the cell surface proteins that play important roles in the generation of these cells. Here we review our current understanding of one of these groups of proteins, the morphogenetic surfactants, with emphasis on the SapB protein of Streptomyces coelicolor.
Dehydroradiosumin, a novel potent trypsin inhibitory dipeptide, was isolated from the freshwater cyanobacterium Anabaena cylindrica (NIES-19). Its structure was elucidated as 1 on the basis of 2D NMR ...data and chemical degradation. The IC50 of 1 against trypsin was 0.1 μg/mL.
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