Isolation and characterization of uridine diphosphate-N-glycolylmuramyl-L-alanyl-γ-D-glutamyl-meso-α,α′-diaminopimelic acid from Mycobacterium tuberculosis

Current ideas on the nature and development of the chromatophores of photosynthetic bacteria are reviewed. A simple method of obtaining purified chromatophores by sucrose density gradient centrifuging of cell-free extracts of Rhodopseudomonas spheroides is described. Such preparations consist of about 60% protein, 20% phospholipid and 10% pigment, most of which is bacteriochlorophyll. Small quantities of carbohydrate, but only traces of nucleic acid, are found. The material was fairly homogeneous on electron microscopy. Rps. spheroides was also grown under pure oxygen in the dark. A particulate preparation from cells cultured under these conditions was similar to the chromatophores with respect to its high content of protein and of phospholipid but had a much greater content of nucleic acid and no bacteriochlorophyll. In addition, it contained amino sugars and diaminopimelic acid which are not found in chromatophores. These differences in chemical composition were correlated with the electron microscope appearances of the different subcellular fractions. It is concluded that the particulate preparation from cells grown under oxygen represents the cytoplasmic membrane of the micro-organism, but as isolated it is heavily contaminated with fragments of the cell wall from which it cannot be readily separated.

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In Vitro Isolation and Characterization of Oxazolidinone-Resistant Mycobacterium tuberculosis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01296-17 ◽

2017 ◽

Vol 61 (10) ◽

Cited By ~ 15

Author(s):

Matthew B. McNeil ◽

Devon D. Dennison ◽

Catherine D. Shelton ◽

Tanya Parish

Keyword(s):

Mycobacterium Tuberculosis ◽

23S Rrna ◽

Clinical Settings ◽

Content Type ◽

Isolation And Characterization ◽

Mutant Strains ◽

Ribosomal Protein L3 ◽

Resistant Strains

ABSTRACT Oxazolidinones are promising candidates for the treatment of Mycobacterium tuberculosis infections. We isolated linezolid-resistant strains from H37Rv (Euro-American) and HN878 (East-Asian) strains; resistance frequencies were similar in the two strains. Mutations were identified in ribosomal protein L3 (RplC) and the 23S rRNA (rrl). All mutant strains were cross resistant to sutezolid; a subset was cross resistant to chloramphenicol. Mutations in rrl led to growth impairment and decreased fitness that may limit spread in clinical settings.

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Isolation and characterization of the monkey UGT2B30 gene that encodes a uridine diphosphate-glucuronosyltransferase enzyme active on mineralocorticoid, glucocorticoid, androgen and oestrogen hormones

Biochemical Journal ◽

10.1042/bj20011594 ◽

2002 ◽

Vol 365 (1) ◽

pp. 213-222 ◽

Cited By ~ 5

Author(s):

Caroline GIRARD ◽

Olivier BARBIER ◽

David TURGEON ◽

Alain BÉLANGER

Keyword(s):

Cynomolgus Monkey ◽

Genomic Organization ◽

Human Kidney ◽

Relative Activity ◽

Pcr Analysis ◽

Uridine Diphosphate ◽

Lipophilic Compounds ◽

Isolation And Characterization ◽

Hormonal Steroids

The present study reports the genomic organization and the characterization of a novel cynomolgus monkey UDP-glucuronosyltransferase (UGT) enzyme, UGT2B30. UGT enzymes are microsomal proteins that catalyse the transfer of the glucuronosyl group from UDP-glucuronic acid (UDPGA) to a wide variety of lipophilic compounds, namely hormonal steroids. The 15kb UGT2B30 gene amplified by PCR showed a genomic organization similar to those encoding UGT2B human enzymes. The cDNA encoding UGT2B30 was isolated from a cynomolgus monkey prostate cDNA library, and the deduced amino acid sequence showed an identity of 94% with UGT2B19, a monkey isoform previously characterized. Stable expression of UGT2B30 protein in human kidney 293 (HK293) cells was assessed by Western-blot analysis and its conjugating activity was screened using 39 potential substrates. The UGT2B30 enzyme is active on many compounds of different classes, including testosterone, dihydrotestosterone, 5α-androstane-3α,17β-diol, androsterone, oestradiol, tetrahydroaldosterone and tetrahydrocortisone, with glucuronidation efficiencies (Vmax/Km ratios) ranging from 0.6 to 8.8μl·min−1·mg of protein−1. Reverse-transcriptase-PCR analysis revealed that the UGT2B30 transcript is expressed in several tissues, including prostate, testis, mammary gland, kidney, adrenals and intestine. The relative activity of UGT2B30 in comparison with other simian UGT2B isoforms, as well as its large variety of substrates, strongly suggest that this enzyme is essential to inactivation of several steroids.

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Isolation and characterization of the peptidoglycans from selected Gram-positive and Gram-negative periodontal pathogens

Canadian Journal of Microbiology ◽

10.1139/m85-030 ◽

1985 ◽

Vol 31 (2) ◽

pp. 154-160 ◽

Cited By ~ 14

Author(s):

M. R. Barnard ◽

S. C. Holt

Keyword(s):

Electron Microscopy ◽

Diaminopimelic Acid ◽

Muramic Acid ◽

Periodontal Pathogens ◽

Gram Positive ◽

Gram Negative ◽

Isolation And Characterization ◽

Bacteroides Gingivalis ◽

Scanning Electron

The peptidoglycans from several Gram-negative and Gram-positive periodontal pathogens were isolated, purified, and characterized both morphologically and chemically. In addition, the effects of the mureolytic enzymes, lysozyme, M-1 N-acetyl-muramidase, and the AM-3 endopeptidase, on the peptidoglycans were examined. These enzymes were found to be highly effective in the degradation of the purified peptidoglycans; however, a Bacteroides capillus peptidoglycan–protein complex exhibited a greater resistance to these enzymes. Morphologically, the peptidoglycans consisted of large saccular sheets which, when viewed by scanning electron microscopy, contained numerous holes and tears. Chemically, the peptidoglycans consisted of muramic acid, glucosamine, alanine, glutamic acid, and meso-diaminopimelic acid (DAP). One Bacteroides species, Bacteroides gingivalis strain W, contained glycine and LL-DAP, suggestive of an indirectly cross-linked A3γ peptidoglycan.

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