Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An extract made from the supernatant of Neisseria gonorrhoeae Gc2 strain 1291 degraded the Gc2 polysaccharide antigen. Chemical analysis of this polysaccharide indicated it contains glucose, galactose, glucosamine, galactosamine, glucosamine-6-phosphate, heptose, 2-keto-3-deoxyotonate, and ethanolamine and is the polysaccharide component of gonococcal lipopolysaccharide. Degradation of the polysaccharide by sonic extracts resulted either in complete loss of antigenicity and immunogenicity or in partial degradation to subunits that could inhibit the Gc2-specific hemagglutination inhibition. The factors responsible for degradation were destroyed by heating at 100 degrees C for 5 min or by Pronase digestion, but were unaffected by ribonuclease, deoxyribonuclease, Mg2+, Ca2+, or ethylenediaminetetraacetic acid. The process was pH dependent, with optimal activity occurring at pH 7. Sonic extract supernatants from group B and C meningococcal strains contained degrading properties, whereas similar extracts produced from Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Streptococcus pneumoniae type II failed to degrade the Gc2 polysaccharide.
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PMID:Degradation of the polysaccharide component of gonococcal lipopolysaccharide by gonococcal and meningococcal sonic extracts. 7 94

Ribosomal preparations from Neisseria gonorrhoeae types 1 and 4 were examined for their in vitro stimulation of mouse splenocytes to determine the ribosomal moiety or contaminant responsible for the immunoproliferative activity. In immunodiffusion tests with homologous rabbit antiserum, crude 70S ribosomes formed four precipitin bands while the purified 30S and 50S subunits showed one major line. The same antiserum reacted with lysed N. gonorrhoeae and Neisseria meningitidis A cells but no precipitation occurred with Escherichia coli cells purified N. gonorrhoeae lipopolysaccharide (LPS). No membrane or LPS contaminant was detected in the purified 30S and 50S preparations. All the ribosomal preparations from virulent and non-virulent N. gonorrhoeae consistently stimulated the murine splenocytes. The mitogenic activity of the 30S and 50S ribosomal preparation was destroyed by treatment with trypsin but only slightly decreased by ribonuclease. It is suggested that the lymphoproliferative response elicited by gonococcal ribosomes is triggered by the protein moiety of the 30S or 50S subunits.
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PMID:Characterization of the mitogenic activity elicited by Neisseria gonorrhoeae ribosomal fractions. 41 60

Lipopolysaccharides, extracted by phenol-water from five strains fo Neisseria gonorrhoeae, were purified by treatment with ribonuclease followed by multiple washes. These preparations were fatal to mice when administered in submicrogram amounts with actinomycin D, the LD50 values varying from 4 to 16 mug/kg. Analyses showed that all preparations contained glucose, galactose, glucosamine, heptose, 2-keto-3-deoxyoctonic acid and phosphate. All the lipopolysaccharides contained the same fatty acids, namely beta-OH-10:0, beta-OH-12:0, beta-OH-14:0, 12:0, 14:0,16:0, 16:1, 18:0 and 18:1. We were unable to detect significant differences between the lipopolysaccharides of virulent and avirulent gonococci or between penicillin-sensitive and resistant strains. Gonococcal lipopolysaccharides appeared to lack O-antigen side chains.
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PMID:Studies on lipopolysaccharides isolated from strains of Neisseria gonorrhoeae. 80 76

Protection against gonococcal infection was obtained by immunization with ribosomal preparations from Neisseria gonorrhoeae. Ribosomes were isolated from disrupted cells by differential ultracentrifugation and treatment of the microsomal fraction with 0.25% sodium dodecyl sulfate. The isolated ribosomal preparations contained 55% ribonucleic acid, 39% protein, and 0.35% carbohydrate. The ribosomal preparations contained small amounts of endotoxin as determined by thiobarbituric acid- and lead acetate-sensitized mice assays. Guinea pigs immunized subcutaneously with ribosomal preparations were challenged intrachamberially with 10(7) colony-forming units of N. gonorrhoeae, and protection was assessed by clearance of the organism from subcutaneous chambers. The ribosomal preparations elicited significant protection, which was enhanced by incoporation of the immunogen into adjuvant. This protection was comparable to that obtained with whole cells. Treatment with proteolytic enzymes destroyed the protective effect of the ribosomal preparations, but ribonuclease had no measurable effect. Passive hemagglutination and immunodiffusion tests with sera from immunized animals demonstrated the presence of antibody to the ribosomal antigens. Results of adsorption of antiribosomal sera with enzyme-treated ribosomal preparations also indicated the protein nature of the immunogen. These results indicate that protein associated with the gonococcal ribosomal preparation is the major protective immunogen. The role of endotoxin contamination in the immunogenicity of gonococcal ribosomal preparations warrants further investigation.
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PMID:Immunogenicity of ribosomal preparations from Neisseria gonorrhoeae. 676 23

In order to better understand the host response to an infection with Neisseria gonorrhoeae, microarray technology was used to analyse the gene expression profile between uninfected and infected human urethral epithelium. The anti-apoptotic genes bfl-1, cox-2 and c-IAP-2 were identified to be upregulated approximately eight-, four- or twofold, respectively, following infection. Subsequent assays including RT-PCR, real time RT-PCR and RNase protection confirmed the increased expression of these apoptotic regulators, and identified that a fourth anti-apoptotic factor, mcl-1, is also upregulated. RT-PCR and RNase protection also showed that key pro-apoptotic factors including bax, bad and bak do not change in expression. Furthermore, our studies demonstrated that infection with the gonococcus partially protects urethral epithelium from apoptosis induced by the protein kinase inhibitor, staurosporine (STS). This work shows that following infection with Neisseria gonorrhoeae, several host anti-apoptotic factors are upregulated. In addition, a gonococcal infection protects host cells from subsequent STS-induced death. The regulation of host cell death by the gonococcus may represent a mechanism employed by this pathogen to survive and proliferate in host epithelium.
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PMID:Infection of human urethral epithelium with Neisseria gonorrhoeae elicits an upregulation of host anti-apoptotic factors and protects cells from staurosporine-induced apoptosis. 1286 14

Neisseria gonorrhoeae, the sole causative agent of gonorrhea, constitutively undergoes diversification of the Type IV pilus. Gene conversion occurs between one of the several donor silent copies located in distinct loci and the recipient pilE gene, encoding the major pilin subunit of the pilus. A guanine quadruplex (G4) DNA structure and a cis-acting sRNA (G4-sRNA) are located upstream of the pilE gene and both are required for pilin antigenic variation (Av). We show that the reduced sRNA transcription lowers pilin Av frequencies. Extended transcriptional elongation is not required for Av, since limiting the transcript to 32 nt allows for normal Av frequencies. Using chromatin immunoprecipitation (ChIP) assays, we show that cellular G4s are less abundant when sRNA transcription is lower. In addition, using ChIP, we demonstrate that the G4-sRNA forms a stable RNA:DNA hybrid (R-loop) with its template strand. However, modulating R-loop levels by controlling RNase HI expression does not alter G4 abundance quantified through ChIP. Since pilin Av frequencies were not altered when modulating R-loop levels by controlling RNase HI expression, we conclude that transcription of the sRNA is necessary, but stable R-loops are not required to promote pilin Av.
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PMID:Transcriptional initiation of a small RNA, not R-loop stability, dictates the frequency of pilin antigenic variation in Neisseria gonorrhoeae. 3133 63