Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00631 (Gel)
 14,881 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A particulate enzyme preparation of Mycobacterium smegmatis catalyzes the transfer of labeled mannose from GDP-[14C] mannose into several endogenous acceptors. In one of these transfer reactions, the radioactivity is incorporated into an insoluble polymeric product that is present at the interphase after extraction of reaction mixture with chloroform-methanol. Solubilization of this product was achieved by digestion with proteolytic enzymes or treatment with 0.1 M NaOH indicating that the material was glycoprotein in nature. The solubilized material obtained after proteolytic digestion followed by treatment with alkali (representing 80-93% of the total interphase product) was shown to consist of a series of small molecular weight [14C] mannose containing oligosaccharides and glycopeptides by Bio-Gel column chromatography. A kinetic study of the enzymatic transfer of [14C] mannose from GDP-[14C] mannose into the glycoprotein suggested that the mannosylphosphorylpolyisoprenols are the obligatory mannosyl donor.
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PMID:The role of mannosylphosphorylpolyisoprenol in glycoprotein biosynthesis in Mycobacterium smegmatis. 111 83

Antigens of Mycobacterium tuberculosis found in the supernatant of heat-treated cultures were characterized in order to explore whether antigens from this source could be used for the development of a serological test. Culture supernatants and sonicates of 12, 25 and 39 d cultures were analysed by SDS-PAGE. In culture supernatant, major protein bands of 65, 24, and 12 kDa were visible after Coomassie brilliant blue staining. Using murine monoclonal antibodies in Western blots, a pattern of protein bands distinct from that of the corresponding M. tuberculosis sonicates was found in all the culture supernatants. Gel permeation chromatography, in the presence of SDS, was used to separate the major protein bands in the culture supernatant. In ELISA, sera from 20 of 26 patients with tuberculosis reacted with fractions containing mainly 24 kDa or 12 kDa proteins, whereas none of the control sera reacted. In Western blots, each patient serum had its own characteristic banding pattern with culture supernatant, but all the sera from tuberculosis patients and control subjects reacted with protein bands of 65, 61, 58, 30 and 24 kDa. The 12 kDa protein was recognized only by sera from patients with tuberculosis in both Western blots and ELISA. This suggests that different kinds of epitopes on proteins of M. tuberculosis are detected by human antibodies in Western blots and ELISA. We assume that epitopes recognized in Western blots by patients with tuberculosis and control subjects are ubiquitous and are also present on normal commensal bacteria. Epitopes recognized by only some patients with tuberculosis in Western blots may be linear and M. tuberculosis specific. Epitopes recognized by tuberculosis patients but by none of the control subjects in ELISA may be conformation related and M. tuberculosis specific. The major protein bands found in supernatants of heat-treated cultures, 24 and 12 kDa, possess epitopes that may be M. tuberculosis specific and are potentially valuable for the development of a serological test.
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PMID:Antigens in culture supernatant of Mycobacterium tuberculosis: epitopes defined by monoclonal and human antibodies. 169 8

To obtain recombinant peptides related to PPDs, we constructed a genomic library from the DNA of Mycobacterium tuberculosis Aoyama B, a standard strain in Japan to manufacture PPDs, using plasmid vectors pUC18 series. Seven clones reacting the anti-PPDs-rabbit-serum on immunoblotting were obtained, and restriction map was analysed. A nucleotide sequence and a putative open reading frame (ORF) of pAT01, encoding 15kD peptide, as well as the mode of expression was reported previously). In this study, nucleotide sequence of 60 kD peptide gene was determined, and the comparative database analysis (GENBANK) revealed a striking level of homology to so called mycobacterial heat shock protein. The expression mode of pAT201 encoding 60 kD, as well as pAT01 encoding 15 kD peptide, indicated that these peptides were not hybrid proteins with the lacZ gene product, but they were consisted of peptides only mycobacterial source. Therefore, 15 kD and 60 kD directly were subjected to immunological studies. The peptides were extracted from E. coli, carrying pAT01 or pAT201, purified through series of DEAE chromatography and followed by Detoxi-Gel to remove LPS. 15 kD peptide behaved almost similar to PPDs both in the DTH skin reaction and the lymphocyte proliferation response on guinea pigs or rats in respect to sensitivity. However, 60 kD was unique in that, and it behaved like a general mitogen. We discussed role of 60 kD peptide, comparing with the common antigen, generally found in most species of bacteria as the heat shock protein.
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PMID:[Molecular cloning and expression of Mycobacterium tuberculosis Aoyama B peptide antigen genes in Escherichia coli--a gene encoding 60 kD antigen (AT201) and immunological activity of recombinant peptides (15 and 60 kD)]. 212 May 4

Sonicates of Mycobacterium intracellulare grown in synthetic medium were separated into ammonium sulfate (50%) precipitable and nonprecipitable fractions. Gel filtration of the precipitable fraction through columns of Sephacryl S-300 resulted in four fractions labeled A, B, C and D in order of elution. Fractions C and D were further fractionated into 12 and 13 subfractions, respectively. The subfractions were examined for reactivity by rocket immunoelectrophoresis (R-IE) procedures and by skin tests in homologously and heterologously immunized guinea pigs (M. kansasii, M. fortuitum, M. marinum, M. scrofulaceum and M. bovis). Extensive sharing of antigenic determinants was observed for all of the reactive subfractions by R-IE. None of the subfractions showed significant skin test specificity. Possible reasons for the nonspecificity are discussed.
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PMID:Serologic and cellular cross-reactivity of fractions of Mycobacterium intracellulare (Battey). 243 98

From the 70% ethanol extract of Mycobacterium smegmatis cells, we isolated a mixture of weakly acidic oligosaccharides composed mainly of glucose and 6-O-methylglucose. The elution pattern from a Bio-Gel P-4 column suggested that the oligosaccharides were smaller than the O-methylglucose polysaccharide (MGP) and could be biosynthetic precursors. Analysis by fast-atom-bombardment mass spectrometry revealed that the oligosaccharides fit into a pattern for polysaccharide synthesis based on an alternate glucosylation-methylation mechanism until the chain reached the composition methylglucose11glucose5glyceric acid, at which time 2 glucose units are added to give glucose2methylglucose11glucose5glyceric acid. The addition of the last 2 glucoses and methylation of one of them to give mature MGP (methylglucose1glucose3methylglucose11glucose5glyceric acid) apparently occurs rapidly because the expected intermediates were not observed. Only 4 glucose units are present at the glyceric acid end of some molecules during all stages of the elongation process, and these represent precursors of a minor MGP homolog with an extra methyl group on the beta 1----3-linked glucose unit of MGP. alpha-D-Glucopyranosyl-(1----2)-D-glyceric acid and alpha-D-glucopyranosyl-(1----6)-alpha-D-glucopyranosyl-(1----2)-D-glycer ic acid were also isolated from the extract and correspond in structure to the expected initial precursors.
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PMID:Biosynthesis of the mycobacterial O-methylglucose lipopolysaccharide. Characterization of putative intermediates in the initiation, elongation, and termination reactions. 355 56

The aminopeptidase activity of three strains of Mycobacterium tuberculosis, H37Rv, H37Ra, and M. tuberculosis from a patient, was partially purified and characterized. The activity from all three organisms was found to be very similar, if not identical. All three aminopeptidases eluted at a similar salt concentration on DEAE Bio-Gel; were active on the same synthetic and peptide substrates; had molecular weights of 75-76,000; were found to be stable between pH 5 and 8, and 4 degrees and 40 degrees C; and had a pH optimum of 7. They were inhibited by low concentrations of Hg2+, Cu2+ and Co2+; metal chelators; and 4-chloromercuribenzoic acid. A number of amino acids and several antibiotics were also found to be inhibitory. Of the antibiotics tested, rifampicin and bacitracin were the most effective.
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PMID:Characterization and comparison of aminopeptidase activity of various strains of Mycobacterium tuberculosis. 680

A new basic peptide antibiotic designated as K-582 was isolated, purified and characterized. When K-582 was applied to a column of Al2O3 or Biol-Gel P-2 or CM Sephadex, two major peaks which were named Fraction I (K-582 A) and Fraction II (K-582 B) were obtained. The nitrogen content, the behavior in color reaction, the absorption bands of amide linkages in the infrared absorption spectrum, 1H NMR spectrum and C-13 NMR spectrum indicated the peptide nature of K-582 A and K-582 B. K-582 was effective against yeasts, but inactive against other Gram-positive bacteria, Gram-negative bacteria and Mycobacterium. The toxicity was low in mice.
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PMID:K-582, a new peptide antibiotic. I. 741 67

The DtxR protein from Corynebacterium diphtheriae is an iron-dependent repressor that regulates transcription from the tox, IRP1, and IRP2 promoters. A gene from virulent Mycobacterium tuberculosis H37Rv was recently shown to encode a protein, here designated iron-dependent regulator (IdeR), that is almost 60% homologous to DtxR from C. diphtheriae. A 750-bp PCR-derived DNA fragment carrying the M. tuberculosis ideR allele was subcloned to both high- and low-copy-number vectors. In Escherichia coli, transcription from the C. diphtheriae tox, IRP1, and IRP2 promoters was strongly repressed by ideR under high-iron conditions, and ideR restored normal iron-dependent expression of the corynebacterial siderophore in the C. diphtheriae dtxR mutant C7(beta)hm723. The M. tuberculosis IdeR protein was overexpressed in E. coli and purified to near homogeneity by nickel affinity chromatography. Gel mobility shift experiments revealed that IdeR bound to a DNA fragment that carried the C. diphtheriae tox promoter/operator sequence. DNAse I footprint analysis demonstrated that IdeR, in the presence of Cd2+, Co2+, Fe2+, Mn2+, Ni2+, or Zn2+, protected an approximately 30-bp region on DNA fragments carrying the tox, IRP1, or IRP2 promoter/operator sequences. IdeR reacted very weakly in Western blots (immunoblots) with antiserum against the C. diphtheriae DtxR protein, suggesting that the immunodominant epitopes of DtxR may be located in its poorly conserved carboxyl-terminal domain.
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PMID:Characterization of an iron-dependent regulatory protein (IdeR) of Mycobacterium tuberculosis as a functional homolog of the diphtheria toxin repressor (DtxR) from Corynebacterium diphtheriae. 759 Oct 59

Evidence of a direct association between ferri-exochelin, the major extracellular siderophore of Mycobacterium smegmatis, and a 29 kDa protein has been obtained by three separate methods. (1) Direct binding of 55Fe(III)-exochelin by the 29 kDa protein in an envelope preparation from iron-deficient cells was demonstrated by the extraction of a complex with the non-denaturing detergent CHAPS, and subsequent CHAPS-PAGE and autoradiography. (2) Affinity chromatography on a chemically synthesized ferri-exochelin-Sepharose 4B matrix led to the retention of the 29 kDa protein and a 25 kDa protein. The smaller protein was partially eluted with 1 mM ferri-exochelin although it did not form a stable complex with ferri-exochelin. The 29 kDa protein could not be eluted from the affinity matrix with 1 mM ferri-exochelin either alone or with 1 M NaCl. Only 2% (w/v) SDS could do this, but resulted in protein denaturation. (3) Incubation of 55Fe-exochelin with CHAPS-solubilized envelope proteins in free solution followed by ion-exchange chromatography resolved three radioactive peaks; subsequent analysis by SDS-PAGE showed that the peak with the highest 55Fe-binding activity per unit protein contained both the 29 and 25 kDa proteins. A direct association was demonstrated between the 29 kDa protein and 55Fe-exochelin by gel filtration. The evidence suggests that the 29 kDa iron-regulated envelope protein of M. smegmatis is a ferri-exochelin-binding protein and that the 25 kDa protein, which corresponds in size to a previously reported iron-regulated envelope protein in this bacterium, may have a role in the formation or maintenance of this complex. Proteins extracted from the cell envelope of iron-deficient M. smegmatis with CHAPS were dialysed to remove the detergent, incorporated into liposome suspensions and then incubated with 55Fe(III)-exochelin. This increased the retention of 55Fe by 133-fold compared to proteins not placed in liposomes. Retention of 55Fe was dependent upon the protein loading of the liposomes. Gel filtration confirmed that the iron was retained by these vesicles and even after dialysis the majority of 55Fe was still retained by the vesicles. Re-solubilization of the labelled proteo-liposomes in various detergents gave limited recovery of a ferri-exochelin-protein complex. Attempts to resolve this complex by Triton X-100 PAGE led to separation of the two entities. The complex was stable, however, in a CHAPS-PAGE system.
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PMID:Identification of a 29 kDa protein in the envelope of Mycobacterium smegmatis as a putative ferri-exochelin receptor. 870 92

We have generated a murine T-cell hybridoma, 1C9, which recognizes an antigen expressed by a virulent clinical isolate of Mycobacterium avium. Both peritoneal exudate macrophages and bone marrow-derived macrophages infected in vitro with M. avium process and present the antigen to the T-cell hybridoma. Gel filtration chromatography of a sonicate of M. avium followed by T-cell Western blotting (immunoblotting) demonstrated that the antigen recognized by hybridoma 1C9 is approximately 50 kDa. In addition, treatment of macrophages with the lysosomotropic agent chloroquine or with inhibitors of acid proteases inhibits processing and presentation of the antigen. These results indicate that the antigen must encounter an acidic compartment with active proteases for processing and presentation to occur. Our results are discussed in the context of our current understanding of how mycobacterial antigens are processed and presented by infected macrophages to T cells.
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PMID:Processing and presentation of an antigen of Mycobacterium avium require access to an acidified compartment with active proteases. 892 74


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