排序方式: 共有47条查询结果,搜索用时 179 毫秒
21.
Jason D. Oliver Sarah J. Kaye Danny Tuckwell Anna E. Johns Darel A. Macdonald Joanne Livermore Peter A. Warn Mike Birch Michael J. Bromley 《PloS one》2012,7(9)
Dihydroxyacid dehydratase (DHAD) is a key enzyme in the branched-chain amino acid biosynthetic pathway that exists in a variety of organisms, including fungi, plants and bacteria, but not humans. In this study we identified four putative DHAD genes from the filamentous fungus Aspergillus fumigatus by homology to Saccharomyces cerevisiae ILV3. Two of these genes, AFUA_2G14210 and AFUA_1G03550, initially designated AfIlv3A and AfIlv3B for this study, clustered in the same group as S. cerevisiae ILV3 following phylogenetic analysis. To investigate the functions of these genes, AfIlv3A and AfIlv3B were knocked out in A. fumigatus. Deletion of AfIlv3B gave no apparent phenotype whereas the Δilv3A strain required supplementation with isoleucine and valine for growth. Thus, AfIlv3A is required for branched-chain amino acid synthesis in A. fumigatus. A recombinant AfIlv3A protein derived from AFUA_2G14210 was shown to have DHAD activity in an in vitro assay, confirming that AfIlv3A is a DHAD. In addition we show that mutants lacking AfIlv3A and ilv3B exhibit reduced levels of virulence in murine infection models, emphasising the importance of branched-chain amino acid biosynthesis in fungal infections, and hence the potential of targeting this pathway with antifungal agents. Here we propose that AfIlv3A/AFUA_2G2410 be named ilvC. 相似文献
22.
Howley Eimear Bestwick Michael Fradley Rosa Harrison Helen Leveridge Mathew Okada Kengo Fieldhouse Charlotte Farnaby Will Canning Hannah Sykes Andy P. Merchant Kevin Hazel Katherine Kerr Catrina Kinsella Natasha Walsh Louise Livermore David G. Hoffman Isaac Ellery Jonathan Mitchell Phillip Patel Toshal Carlton Mark Barnes Matt Miller David J. 《Neurochemical research》2017,42(11):3279-3288
Neurochemical Research - Irregular N-methyl-d-aspartate receptor (NMDAR) function is one of the main hypotheses employed to facilitate understanding of the underlying disease state of... 相似文献
23.
Abstract LXA-1, a novel plasmid-mediated β-lactamase, was observed in clinical isolates of Klebsiella oxytoca, Klebsiella pneumoniae, Citrobacter freundii and Enterobacter cloacae . All the strains additionally produced TEM-1 β-lactamase. LXA-1 had an M r of 24 000 and a pI of 6.7. It hydrolysed benzyl-penicillin, ampicillin, carbenicillin and first generation cephalosporins, but not methicillin, oxacillin or cefotaxime. Clavulanate and cloxacillin were inhibitors. Studies of one of the E. cloacae isolates showed that LXA-1 was encoded by a 41-MDa IncFII plasmid distinct from that encoding TEM-1 enzyme in the strain. Transconjugants which acquired LXA-1 production, but not TEM-1, exhibited only low-level resistance to substrate β-lactams. 相似文献
24.
James W. Myatt Mark P. Healy Gianpaolo S. Bravi Andrew Billinton Christopher N. Johnson Kim L. Matthews Karamjit S. Jandu Wenjing Meng Anne Hersey David G. Livermore Clement B. Douault Jason Witherington Rino A. Bit James E. Rowedder Jason D. Brown Nick M. Clayton 《Bioorganic & medicinal chemistry letters》2010,20(15):4683-4688
Optimization of the novel alpha-2-delta-1 ligand 4 provided compounds 37 and 38 which have improved DMPK profiles, good in vivo analgesic activity and in vitro selectivity over alpha-2-delta-2. An in-house P-gp prediction programme and the MetaSite® software package were used to help solve the specific problems of high P-gp efflux and high in vivo clearance. 相似文献
25.
Carbapenems were the last β-lactams retaining near-universal anti-Gram-negative activity, but carbapenemases are spreading, conferring resistance. New Delhi metallo-β-lactamase (NDM) enzymes are the latest carbapenemases to be recognized and since 2008 have been reported worldwide, mostly in bacteria from patients epidemiologically linked to the Indian subcontinent, where they occur widely in hospital and community infections, and also in contaminated urban water. The main type is NDM-1, but minor variants occur. NDM enzymes are present largely in Enterobacteriaceae, but also in non-fermenters and Vibrionaceae. Dissemination predominantly involves transfer of the blaNDM-1 gene among promiscuous plasmids and clonal outbreaks. Bacteria with NDM-1 are typically resistant to nearly all antibiotics, and reliable detection and surveillance are crucial. 相似文献
26.
Robert J. Gleave Paul J. Beswick Andrew J. Brown Gerard M.P. Giblin Carl P. Haslam David Livermore Andrew Moses Neville H. Nicholson Lee W. Page Brian Slingsby Martin E. Swarbrick 《Bioorganic & medicinal chemistry letters》2009,19(23):6578-6581
2-Amino-5-aryl-pyridines, exemplified by compound 1, had been identified as a synthetically tractable series of CB2 agonists from a high-throughput screen of the GlaxoSmithKline compound collection. Described herein are the results of an investigation of the structure–activity relationships (SAR) which led to the identification a number of potent and selective agonists. 相似文献
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28.
Garrett C. Struckhoff Joshua A. Livermore Gene F. Parkin 《International journal of phytoremediation》2013,15(9):830-843
Chlorite dismutase (cld) is an essential enzyme in the biodegradation of perchlorate. The objective of this study was to determine the change in sequence diversity of the cld gene, and universal bacterial 16S rRNA genes, in soil samples under varying conditions of organic carbon, bioaugmentation, and plant influence. The cld gene diversity was not different between high organic carbon (HOC) and low organic carbon (LOC) soil. Combining results from HOC and LOC soil, diversity of the cld gene was decreased in soil that had been bioaugmented or planted. However, with both bioaugmentation and planting the cld diversity was not decreased. These observations were repeated when focusing on LOC soil. However, in HOC soil the cld diversity was not affected by reactor treatment. General bacterial diversity as measured with 16S rRNA was significantly greater in HOC soil than in LOC soil, but no significant difference was observed between reference soil and planted or bioaugmented soil. Different sequences of the cld gene occur in different species of microorganisms. In LOC soil, combining bioaugmentation and planting results in a highly diverse population of perchlorate degraders. This diverse population will be more resilient and is desirable where perchlorate reduction is a critical remediation process. Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file. 相似文献
29.
Muna H. Abdi Paul J. Beswick Andy Billinton Laura J. Chambers Andrew Charlton Sue D. Collins Katharine L. Collis David K. Dean Elena Fonfria Robert J. Gleave Clarisse L. Lejeune David G. Livermore Stephen J. Medhurst Anton D. Michel Andrew P. Moses Lee Page Sadhana Patel Shilina A. Roman Stefan Senger Brian Slingsby Daryl S. Walter 《Bioorganic & medicinal chemistry letters》2010,20(17):5080-5084
A computational lead-hopping exercise identified compound 4 as a structurally distinct P2X7 receptor antagonist. Structure–activity relationships (SAR) of a series of pyroglutamic acid amide analogues of 4 were investigated and compound 31 was identified as a potent P2X7 antagonist with excellent in vivo activity in animal models of pain, and a profile suitable for progression to clinical studies. 相似文献
30.
Light entrainment of the circadian rhythm of mesolimbic dopamine excitability, measured by the amphetamine-induced locomotor response, and the circadian feeding rhythm was abolished following section of the extraocular muscles of the rat. Endogenous (free-running) circadian rhythms were preserved. The results are consistent with electrophysiologic evidence that the rapid eye movements during paradoxical sleep transmit light-modulated electrical potentials to regions of the brain that influence circadian rhytms and dopamine release. 相似文献