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

The function of BALB/c primary B precursors, responding to dextran (dex) B-1355, and the fine-specificity of the B-1355-binding, lambda and chi, monofocal antibody (Ab) generated by the precursors have been examined. In splenic fragments from Limulus polyphemus haemocyanin (LPH)-primed, lethally irradiated, euthymic or nu/nu BALB/c mice cultured with thymus-independent (TI) dex B-1355, B-1355-lipopolysaccharide (LPS), B-1355-LPS-LPH, or thymus-dependent (TD) dex B-1355-LPH, the lambda 1 precursors responded with B-1355-binding Ab substantially equally with respect to precursor frequency, rate of Ab production, and range of fine-specificity, but not with respect to frequency of the IdX and IdI isotypes related to the VH and DH associated with the lambda 1. The lambda 2 contributed minimally to the repertoire. The chi precursors responded with B-1355-binding Ab at a rate nearly equal to the lambda 1 only under TD stimulus in euthymic fragments. A comparison of the lambda 1 and chi Ab fine-specificity, by inhibition of binding with dex differing in epitope contents and configurations, showed marked restriction in the chi relative to the lambda 1. Only approximately 10% of the relatively more abundant chi TD response showed fine alpha (1 leads to 3) specificity similar to that of the lambda 1. The lambda 1 fine-specificity diversity resided mainly in the IdI fraction.
 ...
PMID:Fine-specificity of the lambda and chi L chains associated with antibodies directed to alpha (1 leads to 3) glucosyls in dextran. 619 14

A lipopolysaccharide (LPS)-binding lectin was recovered from the serum of Limulus polyphemus by ion-exchange chromatography. Electrophoretic analysis of this lectin preparation revealed three poorly migrating bands. When whole serum was incubated with glycolipid obtained from the Rc mutant of Salmonella minnesota prior to electrophoresis, bands corresponding to those seen in the partially purified lectin were missing, suggesting that the recovered material was composed of isolectins. Qualitative precipitin tests revealed no reactivity of this purified lectin with lipid A fractions or with LPS devoid of 2-keto-3-deoxyoctonate (KDO). The agglutination of chicken erythrocytes by this lectin was inhibited by both N-acetyl-neuraminic acid and KDO. Erythrocytes complexed with glycolipid from the Re mutant of S. minnesota were strongly agglutinated by this lectin. We conclude that this LPS-binding lectin is specific for the KDO portion of the molecule and that it is identical to the previously described sialic acid-binding lectin from L. polyphemus. This lectin may play a role in the host defense mechanisms of Limulus.
 ...
PMID:Lipopolysaccharide-binding lectin from the horseshoe crab, Limulus polyphemus, with specificity for 2-keto-3-deoxyoctonate (KDO). 704 48

A new sensitive fluorimetric assay has been developed using peptidyl-3-amino-9-ethyl-carbazole as substrate. The fluorescence intensity of free 3-amino-9-ethyl-carbazole (AEC) at 460 nm is between two and three orders of magnitude higher than the fluorescence intensity of acyl-AEC. The release of AEC from a peptidyl derivative by proteases may be monitored continuously during the hydrolysis step or may be quantified upon addition of a general inhibitor such as benzamidinium chloride. Using N-benzoyl-arginyl-AEC as substrate, as little as 1 ng trypsin may be detected. Using t-butyloxycarbonyl-Val-Leu-Gly-Arg-AEC and the amoebocyte lysate of Limulus polyphemus, as little as 1 pg lipopolysaccharide can be detected. This fluorimetric method allows detection of trace amounts of lipopolysaccharide (endotoxins) in various biological materials, including sera.
 ...
PMID:Assay for proteolytic activity using a new fluorogenic substrate (peptidyl-3-amino-9-ethyl-carbazole); quantitative determination of lipopolysaccharide at the level of one picogram. 718 84

Gram-negative bacterial sepsis is associated with endotoxemia and a high mortality rate. In previous studies, we demonstrated the therapeutic benefit of an anti-lipopolysaccharide factor isolated from amebocytes of Limulus polyphemus, and of a recombinant version of this protein, termed endotoxin neutralizing protein (ENP), in rabbits challenged with purified lipopolysaccharides. To assess the benefit of ENP in treating a live bacterial infection, we established a rabbit model of Escherichia coli (E. coli) peritonitis and bacteremia with high mortality despite gentamicin treatment. Twenty-four pairs of New Zealand white rabbits were challenged intraperitoneally (IP) with E. coli O18ac K1 in 5% porcine mucin (mean bacteria per dose = 2.5 x 10(8)). The animals were treated with intravenous (i.v.) gentamicin (2.5 mg/kg), and with either ENP (5 mg/kg) or saline i.v. at 1 hr after E. coli challenge. All rabbits were bacteremic 1 hr after challenge (geometric mean 4.1 +/- 1.2 x 10(4) cfu/mL). Peak geometric mean serum endotoxin (2.62 v 10.54 EU/mL, P = .013) and tumor necrosis factor (TNF) (2540 v 6438 TNF units/mL, P = .046) concentrations were lower in ENP-treated animals as compared to control animals. Seven of 24 animals treated with ENP survived 24 hr compared with 4 of 24 controls (Kaplan-Meier analysis, P = .19). However, in the subgroup of 13 paired animals in whom bacteremia was eliminated by gentamicin treatment, 5 of 13 ENP-treated animals survived 24 hr, compared with 1 of 13 controls (Kaplan-Meier analysis, P = .032).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Efficacy of a recombinant endotoxin neutralizing protein in rabbits with Escherichia coli sepsis. 801 61

Endotoxin neutralizing protein (ENP), a recombinant form of the anti-lipopolysaccharide factor that was isolated from amebocytes of the American horseshoe crab, Limulus polyphemus, detoxifies lipopolysaccharide (LPS) both in vitro and in vivo. Using the Limulus amebocyte lysate assay, LPS was detoxified by ENP at a 1 to 1 weight ratio (1:1). When isolated rat aortic rings were preincubated for 16 hr with either LPS or LPS/ENP (1:5), only aortas in the LPS/ENP group contracted normally under norepinephrine stimulation. To show that detoxification of a lethal amount of LPS (18 mg/kg, LD50 at 48 hr) persists in vivo, LPS/albumin (1:1) or LPS/ENP (1:1) mixtures were preincubated (30 min, 37 degrees C) and then injected intravenously into rats. In the 8 hr after injection, LPS/ENP challenged rats, in contrast to their LPS/albumin injected counterparts, had significantly fewer physical signs of acute LPS toxicity (P < 0.001). At 48 hr after challenge, all LPS/ENP treated rats survived (P < 0.01 vs LPS/albumin), and with significantly less weight loss (P < 0.001 vs LPS/albumin challenged survivors). At necropsy, the LPS/ENP group was free of typical LPS-induced gross organ lesions, notably in the liver, spleen, gut-associated lymphoid tissue (GALT), and small intestine. By microscopic examination, lymphocytic necrosis in the spleen and GALT of the LPS/ENP treated survivors was significantly milder than that in the LPS/albumin challenged survivors, although the degree of hepatocellular necrosis and small intestinal enteritis was similar. LPS-neutralizing proteins such as ENP may be useful in treating LPS toxicity.
 ...
PMID:Lipopolysaccharide detoxification by endotoxin neutralizing protein. 841 93

Limulus amebocyte lysate, obtained from horseshoe crab (Limulus polyphemus) blood cells, contains a coagulation system which is activated by bacterial lipopolysaccharide (LPS). A chromatographic fraction of Limulus lysate, containing the endotoxin-sensitive factor(s) which initiates the coagulation cascade, was studied. We utilized a photoreactive, cleavable, radiolabeled derivative of Salmonella minnesota LPS, LPS-(p-azidosalicylamido)-1,3'-dithiopropionamide (LPS-ASD), to identify LPS-binding proteins. The lysate fraction was incubated with LPS-ASD, and LPS-binding proteins were identified by autoradiography of sodium dodecyl sulfate-polyacrylamide gels. An 82-kDa protein, a major protein component of this fraction from Limulus lysate, was identified as a LPS-binding protein in a majority of lysates. Incubation of whole Limulus lysate with antiserum to this protein resulted in enhanced sensitivity of the lysate to LPS, suggesting that this 82-kDa protein is a negative regulator of coagulation. A minor 50-kDa protein component of lysate also was identified as a LPS-binding protein and is a candidate for the LPS-sensitive coagulation protein in L. polyphemus.
 ...
PMID:Lipopolysaccharide-binding proteins of Limulus amebocyte lysate. 843 86

Here we report evidence for T cell dependent intermolecular-induced suppression of antibody responses in fish, using a panel of T cell dependent (TD) and T cell independent (TI) hapten-carrier antigens. Atlantic salmon were immunized intraperitoneally either with protein antigens: Limulus polyphemus hemocyanin (LPH), chicken gammaglobulin (CGG), A. salmonicida surface A-layer protein (ALPAsal) or lipopolysaccharide (LPS) antigens isolated from A. salmonicida and Escherichia coli. The various antigens were given as a mixture of the native and haptenated (4-hydroxy-3-iodo-5-nitrophenyl-acetic acid, NIP; 2,4,6-trinitrophenyl-acetic acid, TNP; fluorescein-5-iso-thiocyanate, FITC) forms. The salmon immune system responded to the antigen mixtures by eliciting high anti-hapten titers whereas the antibody titers against protein determinants were low (suppress 65-95%) as determined by ELISA. The suppression was induced between haptens (NIP and FITC) and between heterologous antigens (NIP-CGG and LPH) indicating that the mechanisms involved were non-specific. Moreover, suppression was induced by TD antigens only, indicating that the mechanism was T cell dependent. Injection of antigen mixtures containing variable amounts of the competing antigens showed that the kinetics of suppression was dose-ratio and dose dependent. In a time-course study it was found that the suppressed anti-LPH response was unchanged until native LPH was injected almost 2 years after the primary immunization, showing that permanent tolerance had not been induced. Sequential immunization showed that the antibody response was most sensitive to suppression during the initial 10 days after immunization. Moreover, the carrier antigen was also able to induce suppression of hapten epitopes, but only if the anti-carrier response was allowed to develop for 14 days before the hapten-carrier antigen was injected. This shows that AIS in fish is elicited as a result of the immune response to the dominant antigen, and can be induced against either antigens if the temporal order of administration is reversed. A possible model for AIS as a normal immunoregulatory process in fish is proposed and discussed.
 ...
PMID:Immunoregulation in fish II: intermolecular-induced suppression of antibody responses studied by haptenated antigens in atlantic salmon (Salmo salar L). 865 66

Coelomic fluid of Eisenia foetida earthworms contains a 42-kDa protein named coelomic cytolytic factor 1 (CCF-1) that was described previously to be involved in cytolytic, opsonizing, and hemolytic properties of the coelomic fluid. Cloning and sequencing of CCF-1 reveal significant homology with the putative catalytic region of beta-1,3- and beta-1,3-1,4-glucanases. CCF-1 also displays homology with coagulation factor G from Limulus polyphemus and with Gram-negative bacteria-binding protein of Bombyx mori silkworm, two proteins involved in invertebrate defense mechanisms. We show that CCF-1 efficiently binds both beta-1,3-glucan and lipopolysaccharide. Moreover, CCF-1 participates in the activation of prophenoloxidase cascade via recognition of yeast and Gram-negative bacteria cell wall components. These results suggest that the 42-kDa CCF-1 protein of E. foetida coelomic fluid likely plays a role in the protection of earthworms against microbes.
 ...
PMID:Identification and cloning of a glucan- and lipopolysaccharide-binding protein from Eisenia foetida earthworm involved in the activation of prophenoloxidase cascade. 973 2

DFNA9 is an autosomal dominant, nonsyndromic, progressive sensorineural hearing loss with vestibular pathology. Here we report three missense mutations in human COCH (previously described as Coch5b2), a novel cochlear gene, in three unrelated kindreds with DFNA9. All three residues mutated in DFNA9 are conserved in mouse and chicken Coch, and are found in a region containing four conserved cysteines with homology to a domain in factor C, a lipopolysaccharide-binding coagulation factor in Limulus polyphemus. COCH message, found at high levels in human cochlear and vestibular organs, occurs in the chicken inner ear in the regions of the auditory and vestibular nerve fibres, the neural and abneural limbs adjacent to the cochlear sensory epithelium and the stroma of the crista ampullaris of the vestibular labyrinth. These areas correspond to human inner ear structures which show histopathological findings of acidophilic ground substance in DFNA9 patients.
 ...
PMID:Mutations in a novel cochlear gene cause DFNA9, a human nonsyndromic deafness with vestibular dysfunction. 980 53

Endotoxin neutralizing protein (ENP) from Limulus polyphemus is an amphipathic, 11.8 kDa protein with an isoelectric point of 10.2. ENP neutralizes lipopolysaccharide (LPS) and possesses antibacterial activity against Gram-negative bacteria. Heparin binds to ENP and blocks its LPS-neutralizing activity. The relative blocking activity of heparin is equal to low molecular weight heparin and polyanetholsulfonic acid > heparan sulfate > chondroitin sulfate A > chondroitin sulfate C. Endoproteinase Glu-C hydrolysis of recombinant ENP results in four major peptides, three of which are seen following separation on reversed phase HPLC. Heparin binds to the loop peptide (31-72), which includes the heparin binding consensus sequence XBBXBX between the two cysteine residues of ENP. When heparin is added to the digest and then applied to a C18 column, the loop peptide is bound; however, it dissociates and elutes with either 5 M NaCl or 0.1 M sodium phosphate, demonstrating reversible binding to heparin. LPS and lipid A both bind to the loop peptide and remove it from digests of ENP; however, neither complex could be dissociated by salt or sodium phosphate. Heparin, LPS, and lipid A individually bind to the same site on ENP.
 ...
PMID:Reversible binding of heparin to the loop peptide of endotoxin neutralizing protein. 1106 Oct 28


<< Previous 1 2 3 4 Next >>