Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heat-labile enterotoxin (LT) produced by a human strain of enterotoxigenic Escherichia coli (286C(2)) was purified to homogeneity from pH extracts of fermentor-grown cells by ultrafiltration, (NH(4))(2)SO(4) fractionation, hydrophobic chromatography on norleucine-Sepharose 4B, hydroxylapatite chromatography, and Bio-Gel P-150 filtration. Purified LT preparations exhibited biological activity comparable to that of cholera toxin in four bioassays specific for the two enterotoxins (Y-1 adrenal tumor cells, Chinese hamster ovary cells, pigeon erythrocyte lysates, and skin permeability test). The overall yield of LT protein was 20%, which represented a 500-fold purification over pH extracts. A native molecular weight of 73,000 was determined by gel electrophoresis. The toxin dissociated upon treatment with sodium dodecyl sulfate, pH 7.0, into two components with molecular weights of 44,000 and 30,000. Purified LT preparations were remarkably stable over a wide range of storage conditions, temperatures, and pH's. The biological activity was increased by incubation with trypsin and completely destroyed by pronase and proteinase K, whereas deoxyribonuclease I, ribonuclease, and phospholipase D had no effect. The amino acid composition of purified LT was quite different from that of cholera toxin. Neither carbohydrate nor lipopolysaccharide was present in purified preparations. The purification scheme appeared applicable to LT produced by other human and porcine enterotoxigenic strains, but reflected the amount of LT produced by each strain. These data show that LT and cholera toxin share many common chemical and physical properties, but must be purified by different techniques.
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PMID:Purification and chemical characterization of the heat-labile enterotoxin produced by enterotoxigenic Escherichia coli. 3 93

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

Antiserum to a purified type R lipopolysaccharide antigen isolated from Neisseria gonorrhoeae was used in a slide agglutination test and compared with conventional carbohydrate utilization and fluorescent antibody tests to confirm the identity of laboratory cultures classified as typical or "atypical" N. gonorrhoeae. Cultures of Corynebacterium vaginalis, N. meningitidis, N. catarrhalis, N. sicca, and N. lactamicus were also tested in the slide agglutination procedure. The addition of both deoxyribonuclease and ribonuclease (1 mg/ml) to the cell suspension medium of phosphate-buffered saline improved the sensitivity and specificity of the agglutination reaction for N. gonorrhoeae. Problems relating to the agglutination test as an aid in identification of N. gonorrhoeae are discussed.
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PMID:Nuclease enhancement of specific cell agglutination in a serodiagnostic test for Neisseria gonorrhoeae. 11 Aug 30

Mutants of Salmonella typhimurium with defects in the heptose region of the lipopolysaccharide (LPS) molecule (heptose-deficient, chemotype Re) leak periplasmic enzymes (acid phosphatase (EC 3.1.3.2), cyclic phosphodiesterase, ribonuclease I (EC 3.1.4.22), and phosphoglucose isomerase (EC 5.3.1.9) (PGI is at least partially periplasmic in E. coli and S. typhimurium; see below)) and do not leak an internal enzyme (glucose-6-phosphate dehydrogenase) into the growth medium. The extent of this leakage is markedly increased at higher temperature (42 degrees C). Leakage of periplasmic enzymes from the strains lacking units distal to heptose I in the LPS molecule (chemotype Rd2) occurs only at 42 degrees C, and not at 30 or 37 degrees C. The extent of leakage of these enzymes from smooth strain and mutants of other LPS chemotypes (Rc, Rd1) is not significant, and is not influenced by growth temperatures. The kinetics of leakage of periplasmic enzymes after shift to 42 degrees C in nutrient broth reveal an accelerated release into the medium from heptose-deficient strains of cyclic phosphodiesterase and ribonuclease I after 30 min at 42 degrees C, and phosphoglucose isomerase after 60 min at 42 degrees C; at 30 degrees C the rate of release of cyclic phosphodiesterase and ribonuclease I is relatively slower. After 60 min at 42 degrees C in nutrient broth, growth of these strains has either slowed down or stopped. In L-broth, which permits the growth of the heptose-deficient strain (SA1377) at 42 degrees C, leakage of cyclic phosphodiesterase and phosphoglucose isomerase occurs, whereas there is no detectable leakage of these enzymes from the isogenic smooth strain (SA1355). Thus, leakage of the periplasmic enzymes from the heptose-deficient strain occurs with or without growth. Mg2+ (0.75 mM), sodium chloride (50 mM), and sucrose (100 mM) in nutrient broth at 42 degrees C prevent the leakage of these enzymes. The shedding of LPS from the heptose-deficient as well as the smooth strains is enhanced by high temperature (42 degrees C), whereas considerable leakage of protein occurs only in the heptose-deficient strain at 42 degrees C and not in the smooth strain. The smooth and heptose-deficient strains are equally sensitive to osmotic shock although a significant proportion of acid phosphatase and cyclic phosphodiesterase activities from the heptose-deficient cells grown at 42 degrees C comes off in the Tris-NaCl wash step suggesting a rather loose attachment of these enzymes onto the cell surface.
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PMID:Leakage of periplasmic enzymes from lipopolysaccharide-defective mutants of Salmonella typhimurium. 18

The medium of cultured, SiO2-treated peritoneal macrophages contained a factor which enhances the incorporation of labelled proline to collagen and other proteins in granulation tissue slices, cells and polysomes. Simultaneously, the activity of alkaline RNase in the whole medium was decreased in comparison with the corresponding control. Polyvinylpyridine-N-oxide, PVNO, protected the macrophages against SiO2. Latex-particles and E. coli lipopolysaccharide decreased the RNase activity in the macrophage medium, but unlike SiO2 did not cause liberation of the collagen synthesis-stimulating factor. Fractionation of the medium by gel filtration chromatography showed the SiO2-pretreatment to have caused a very significant decrease in the aggregation state of RNase. The fraction from gel filtration chromatography that contained the SiO2-liberated factor stimulating collagen synthesis also contained the disaggregated RNase. There was no RNase-activity in the control sample. A homogenous protein (mol. wt. 14,300) was isolated with repeated gel filtrations from the medium of silica-treated macrophages. It increased the incorporation of 3H proline and 3H thymidine into cultured granuloma cells.
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PMID:Fractionation of connective-tissue-activating factors from the culture medium of silica-treated macrophages. 22 24

Membrane-defective mutants of Escherichia coli J5 were isolated on the basis of supersensitivity to the antibiotic novobiocin. These mutants display an increased sensitivity to a wide range of antibiotics and to several dyes and detergents. In addition, several mutants leak the periplasmic enzymes, alkyline phosphatase and ribonuclease. This evidence indicates an outer membrane defect in these mutants. The inner and outer membranes of one mutant were separated and subjected to compositional analysis. A deficiency in galactose containing lipopolysaccharide in the outer membrane of the mutant was observed. Two possible causes of this deficiency were examined and discounted: defective galactose uptake into the cell, and defective translocation of lipopolysaccharide from the inner membrane. Extraction and chemical analysis of mutant and wild type lipopolysaccharides suggests that the mutant is defective in the enzyme which transfers glucose to the growing lipopolysaccharide core, UDPglucose transferase. Thus, the mutant's deficiency in galactose-containing lipopolysaccharide can be ascribed to the fact that addition of glucose to the lipopolysaccharide core is a prerequisite for galactose addition. The physiological implications of this alteration are discussed.
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PMID:Biosynthesis and structure of lipopolysaccharide in an outer membrane-defective mutant of Escherichia coli J5. 32 11

Heat-stable enterotoxin (ST) produced by porcine strains of enterotoxigenic (ENT+) Escherichia coli has been purified to apparent homogeneity by sequential ultrafiltration, acetone fractionation, preparative gel electrophoresis, diethylaminoethyl Bio-Gel A ion-exchange chromatography, and Bio-Gel P-10 gel filtration. The enterotoxin, purified more than 1,500-fold, exhibited a molecular weight of 4,400, as determined by both sodium dodecyl sulfate-gel electrophoresis and gel filtration. A molecular weight of 5,100, representing 47 residues, was calculated from amino acid analysis data. The amino acid content was distinctive, with an unusually high proportion of cystines and few hydrophobic amino acids. A single amino-terminal residue, glycine, was observed. Purified ST was stable to heating (100 degrees C, 30 min) and did not lose biological activity after treatment with Pronase, trypsin, proteinase K, deoxyribonuclease, ribonuclease, and phospholipase C. Periodic acid oxidation and several organic solvents (acetone, phenol, chloroform, and methanol) had no effect on the biological activity of ST. Further, purified ST was stable to acid treatment at pH 1.0 but lost biological activity at pH values greater than 9.0. Neither lipopolysaccharide nor lipid contamination was evident in purified preparations. A characteristic absorption spectrum was observed during the course of the purification, which shifted from a maximum at 260 nm in crude preparations to 270 nm for the purified toxin. Antiserum obtained from rabbits immunized with ST or ST coupled to bovine serum albumin neutralized the action of the enterotoxin in suckling mice; however, passive hemagglutination and hemolysis titer assays suggested that ST is a poor antigen.
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PMID:Purification and chemical characterization of the heat-stable enterotoxin produced by porcine strains of enterotoxigenic Escherichia coli. 34 81

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

Mutants of Escherichia coli K12, deficient in up to three major outer membrane proteins b, c and d have been constructed. Mutants that lack the lipopolysaccharide sugar heptose are deficient in protein b. All heptose-deficient strains are supersensitive to lysozyme, various antibiotics and detergents. They excrete the periplasmic enzyme ribonuclease I. Mutants deficient in proteins c and/or d have the same sensitivity towards these compounds as the parent strain. Cells of single, double and triple mutants are all rod-shaped. Electrophoretic analysis of cell envelope proteins indicates that in some mutants the protein deficiency is partially compensated for by increased amounts of one or two of the other major outer membrane proteins. Heptose-deficient strains have an increased amount of 2-keto-3-deoxyoctonate.
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PMID:Heptose-deficient mutants of Escherichia coli K12 deficient in up to three major outer membrane proteins. 78 63

The cells of P. multocida strain P-1059 were destroyed with the French pressure cell; the ribosomal fraction proven to be homogeneous by analytical ultracentrifugation was obtained from the product by centrifugal fractionation, zonal electrophoresis, and Sephadex G-200 gel filtration. The ribosomal fraction exhibited intense protective antigenicity in mice and chickens, but the lipopolysaccharide (endotoxin) and the other bacterial cell fraction obtained in this experiment did not. Sodium deoxycholate treatment of the ribosomal fraction resulted in only a 13% loss in immunological activity, and ribonuclease treatment caused a 60% loss of activity.
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PMID:Immunogenic activity of a ribosomal fraction obtained from Pasteurella multocida. 83 95


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