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)

The polypeptide of uromodulin, an immunosuppressive glycoprotein isolated from human urine, has been shown to be identical to that of Tamm-Horsfall glycoprotein and is synthesized exclusively in the kidney (Hession, C., Decker, J. M., Sherblom, A. P., Kumar, S. (1987) Science 237, 1479-1484). Uromodulin binds recombinant murine interleukin 1 alpha with high affinity, and this binding can be inhibited by addition of specific saccharides (Muchmore, A. V., and Decker, J. M. (1987) J. Immunol. 138, 2541-2546). We now report that uromodulin binds recombinant human tumor necrosis factor (rTNF) with high affinity. Both diacetylchitobiose and Man(alpha 1-6)(Man(alpha 1-3]-Man-O-ethyl are effective inhibitors of the binding, whereas a wide variety of other saccharides are not inhibitory. Although Tamm-Horsfall glycoprotein contains predominantly tetraantennary N-linked chains, the binding to rTNF is unaffected by removal of terminal sialic acid, galactose, and N-acetylhexosamine residues. Fractionation of a Pronase digest of uromodulin by gel filtration yields material that inhibits the binding of uromodulin to rTNF but is of lower molecular weight than the major oligosaccharide. Uromodulin does not inhibit the cytotoxic activity of rTNF as monitored by lysis of tumor cell targets but effectively protects mice from lethal challenge with lipopolysaccharide, an event that may involve lymphokine toxicity. We have previously shown that rTNF binds to sections of human kidney and is localized in the same region as uromodulin. Thus, rTNF interacts with uromodulin via carbohydrate chains that are less processed than the major tetraantennary chain, and this interaction may be critical in promoting clearance and/or reducing toxicity of TNF and other lymphokines.
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PMID:The lectin-like interaction between recombinant tumor necrosis factor and uromodulin. 335 92

Interleukin 1 (IL 1) is a polypeptide hormone produced by activated macrophages that affects many different cell types involved in immune and inflammatory responses. The cloning and expression of a murine IL 1 cDNA in Escherichia coli encoding a polypeptide precursor of 270 amino acids has been reported, and expression of the carboxy-terminal 156 amino acids of this precursor in E. coli yields biologically active IL 1. By using the murine IL 1 cDNA as a probe, we have isolated its human homolog from cDNA generated to lipopolysaccharide-stimulated human leukocyte mRNA. Nucleotide sequence analysis of this cDNA predicts a protein of analysis of this cDNA predicts a protein of 271 amino acids (termed IL 1 alpha) which shows congruent to 61% homology to its murine counterpart but only 27% homology to a recently characterized human IL 1 precursor (IL 1 beta). We have expressed the carboxy-terminal 154 amino acids of IL 1 alpha in E. coli, purified this protein to homogeneity, and have compared it with pure recombinant murine IL 1 in several different IL 1 assays based on murine and human cells. Recombinant IL 1 is capable of stimulating T cell and fibroblast proliferation and inducing fibroblast collagenase and prostaglandin production, thus proving that a single molecule has many of the activities previously ascribed to only partially purified IL 1 preparations. Our results indicate that there exists a family of at least two human IL 1 genes (alpha and beta) whose dissimilar protein products have similar biological activities.
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PMID:Recombinant human interleukin 1 alpha: purification and biological characterization. 348 52

We searched for mouse thymocyte surface proteins attached to the cell membrane through a phosphatidylinositol (PI)-containing glycolipid similar to that identified in the T cell-activating Thy-1 glycoprotein. Our approach was to biochemically analyse the supernatants of 125I surface-labeled thymocytes treated with 60 U/ml of Staphylococcus aureus PI-specific phospholipase C (PI-PLC). In addition to Thy-1, two molecules of Mr 13,000 and 52,000 were found to be specifically solubilized by the enzymatic treatment. The 52,000 structure is a single basic polypeptide of Mr 50,000 under non-reducing conditions. Two-dimensional gel electrophoresis analyses resolved the 13,000 mol. wt molecules in three relatively basic components including (i) a monomeric molecule(s), a fraction of which exhibited slower migration in reducing gels, and (ii) disulfide-linked multimeric structures comprising a major component of Mr 30,000 and a minor one of Mr 45,000. These 52,000 and 13,000 mol. wt molecules could be released from thymocytes and Escherichia coli lipopolysaccharide (LPS)-stimulated B cell blasts, but not from a variety of mature T cell populations. These data add new members to the list of PI-linked rodent lymphoid cell differentiation markers, which already includes three activation signal-transducing T cell molecules (i.e. Thy-1, Ly-6-linked T cell-activating proteins, and RT-6).
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PMID:Two novel phospholipid-linked mouse thymocyte surface molecules released by phosphatidylinositol-specific phospholipase C. 350 37

The inhibition of mitogen induced differentiation by antibodies directed against cell surface immunoglobulins has been used as a polyclonal model system for the study of immune complex mediated down-regulation of the B cell response. The mechanism of this inhibition may also be similar to the ability of gamma globulins coupled to haptens to induce hapten specific B cell tolerance. By biosynthetic labeling of newly synthesized mRNA and of polypeptide chains, the molecular level of inhibition of lipopolysaccharide (LPS) induced B cell differentiation by whole anti-immunoglobulins (anti-Ig) has been examined. It was found that neither blast transformation nor initiation of DNA synthesis is prevented. However, the specific enhancement of transcription of the mu and kappa chain genes induced by LPS is inhibited resulting in the total abrogation of the increase in steady state level of mu s mRNA. In contrast, the basal level of transcription necessary for maintenance of the synthesis of mRNA for membrane IgM and IgD is not affected. Accordingly, it is the specific inhibition of enhanced initiation of RNA polymerases at the mu-delta gene complex which results in the previously documented decrease in IgM secretion. Moreover, since there is also no detectable C gamma transcription in cells stimulated with LPS in the presence of anti-Ig, the further differentiation of IgG secretion in LPS stimulated cells is also prevented.
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PMID:Molecular basis for the inhibition of LPS induced differentiation by anti-immunoglobulin. 350 22

cDNA clones containing the entire sequence of the precursor of rabbit tumor necrosis factor (TNF) were identified from a cDNA library prepared using poly(A)+RNA of lipopolysaccharide-induced rabbit alveolar cells. Synthetic oligodeoxynucleotides based on the amino acid sequence of rabbit TNF were selected by RNA blot hybridization and used as probes to screen this library. The DNA sequence and the amino acid sequence deduced from it showed very high homology to the reported DNA and amino acid sequences of human TNF. A plasmid containing the tac promoter and cDNA sequence coding for the 154-amino-acid sequence of mature rabbit TNF protein was constructed and expressed in Escherichia coli. The polypeptide produced had the characteristics of purified rabbit serum TNF and caused a necrotic response in a transplanted syngeneic tumor in mice.
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PMID:Molecular cloning and expression in Escherichia coli of the cDNA coding for rabbit tumor necrosis factor. 351 37

The effect of lipopolysaccharide on RNA polymerase I activity in primary cultures of murine B lymphocytes has been examined. In cells treated with mitogen for 48 h, the activity of RNA polymerase I was approximately 15 times greater than in control cells. In situ localization of RNA polymerase I using indirect immunofluorescence indicated that there was at least a 10-fold increase in the amount of this enzyme associated with nucleoli of 48 h mitogen-treated cells relative to control cells. Immunoblotting experiments demonstrated a similar increase in the concentration of the 190-kDa subunit bound to DNA; the concentrations of the other polymerase I-associated polypeptides did not correlate with rRNA synthesis. Assuming 1 mol of the 190-kDa polypeptide/mol of polymerase I, it was estimated that 2,300 and 30,000 molecules of enzyme were associated with rDNA in the unstimulated and stimulated B cell, respectively. Thus, an increased cellular concentration of the 190-kDa subunit of RNA polymerase I and its association with ribosomal DNA may be a crucial step in rRNA synthesis.
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PMID:Lipopolysaccharide-mediated induction of RNA polymerase I activity and amount in murine B lymphocytes. 352 71

The complete amino acid sequence of anti-lipopolysaccharide (LPS) factor purified from the hemocytes lysate of the American horseshoe crab, Limulus polyphemus, was determined by characterization of the NH2-terminal sequence and the peptides generated after digestion of the protein with lysyl endopeptidase, clostripain, and Staphylococcus aureus V8 protease. Upon sequencing the peptides by the automated Edman method, the following primary structure was obtained: (Sequence: in text). During the sequence analysis, two species of the protein, which differed from each other at one locus, were found and characterized. L. polyphemus anti-LPS factor was a basic protein consisting of a single polypeptide chain of 101 residues and a calculated molecular weight of 11,786 or 11,800. The hydrophobic NH2-terminal sequence and the clustering of positive charges found in the disulfide loop yielded a typical amphipathic character of this protein. Moreover, L. polyphemus anti-LPS factor showed 83% sequence identity with the Tachypleus tridentatus protein, and the sequence similar to that observed in the EF-hand structure was found to contain in the COOH terminal portions of these proteins, although its function is unknown.
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PMID:Primary structure of anti-lipopolysaccharide factor from American horseshoe crab, Limulus polyphemus. 366 49

Cell-mediated immune responses in cattle infected with Brucella abortus Strain 544, cattle infected with Yersinia enterocolitica serotype 09 and non exposed cattle were studied by an in vitro whole-blood lymphocyte stimulation procedure. A soluble Brucella polypeptide containing some lipopolysaccharide prepared from Brucella abortus strain 99 was used as antigen while Concanavalin A was used as mitogen. Results were assayed for (6-3H) thymidine incorporation into deoxyribonucleic acid. All the cattle from which Brucella abortus was recovered developed very high lymphocyte transformation responses while cattle infected with Yersinia enterocolitica 09 and non exposed cattle did not develop high lymphocyte stimulation reactions. The animals infected with Yersinia enterocolitica 09 were strongly positive to the Rose Bengal, serum agglutination, Complement fixation and Coombs' antibovine globulin tests. One lactating cow infected with Yersinia enterocolitica 09 was positive to the Brucella milk ring test. It was concluded that the lymphocyte stimulation assay could be used to differentiate bovine brucellosis from yersiniosis.
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PMID:Differentiation of Brucella abortus and Yersinia enterocolitica serotype 09 infections: use of lymphocyte transformation test. 393 92

Exposure of limulus hemocytes to bacterial endotoxins (lipopolysaccharide, LPS) results in the activation of the intracellular clotting system, consisting of several protein components. During the separation of these components, a potent anticoagulant, named anti-LPS factor, which inhibits the endotoxin-mediated activation of the coagulation cascade, was found in hemocytes from both Tachypleus tridentatus and Limulus polyphemus (Tanaka, S., et al. (1982) Biochem. Biophys. Res. Commun. 105, 717-723). The principle isolated from the Tachypleus hemocyte lysate by column chromatographies on dextran sulfate-Sepharose CL-6B and Sephadex G-50 under sterile conditions was a simple basic protein with an apparent molecular weight of 15,000. It consisted of a single chain polypeptide containing a total of 128 amino acids. The COOH-terminal end was presumed to be histidine, but no NH2-terminal end reactive to phenylisothiocyanate was detected. The isolated anti-LPS factor specifically inhibited the endotoxin-mediated activation of factor C, which has recently been identified as an LPS-sensitive serine protease zymogen in the hemocytes. This inhibition appeared to be due to the binding of anti-LPS factor with LPS. Moreover, anti-LPS factor had an antibacterial effect on the growth of Gram-negative bacteria (Salmonella minnesota R595 and 1114W) but not on that of Gram-positive bacteria (Staphylococcus aureus 209P). These biological activities of the isolated anti-LPS factor suggest an important role in cellular defence of limulus against microbial invasion.
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PMID:Isolation and biological activities of limulus anticoagulant (anti-LPS factor) which interacts with lipopolysaccharide (LPS). 403 Jul 41

Previous studies have shown that the outer membrane of Escherichia coli O111 gives a single, major, 42,000-dalton protein peak when analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis at neutral pH. Further studies have shown that this peak consists of more than a single polypeptide species, and on alkaline SDS-gel electrophoresis this single peak is resolved into three subcomponents designated as proteins 1, 2, and 3. By chromatography of solubilized, outer membrane protein on diethylaminoethyl-cellulose followed by chromatography on Sephadex G-200 in the presence of SDS, it was possible to separate the 42,000-dalton major protein into four distinct protein fractions. Comparison of cyanogen bromide peptides derived from these fractions indicated that they represented at least four distinct polypeptide species. Two of these proteins migrated as proteins 1 and 2 on alkaline gels. The other two proteins migrated as protein 3 on alkaline gels and cannot be separated by SDS-polyacrylamide gel electrophoresis. In purified form, these major proteins do not contain bound lipopolysaccharide, phospholipid, or phosphate. These proteins may contain a small amount of carbohydrate, as evidenced by the labeling of these proteins by glucosamine, and to a lesser extent by glucose, under conditions where the metabolism of these sugars to amino acids and lipids is blocked. All of the proteins were labeled to the same extent by these sugars. Thus, it was concluded that there are at least four distinct polypeptide species with apparent molecular masses of about 42,000 daltons in the outer membrane of E. coli O111.
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PMID:Outer membrane proteins of Escherichia coli. 3. Evidence that the major protein of Escherichia coli O111 outer membrane consists of four distinct polypeptide species. 420 34


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