Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A recently developed solid-phase binding assay was used to investigate the specificity of ligand binding to a mouse monoclonal anti-dinitrophenyl IgE [IgE(aDNP)]. All DNP-amino acids, that were tested, inhibited the binding of radio-labeled IgE(aDNP) to DNP covalently attached to polystyrene microtiter plates; however, the concentration for 50% inhibition varied within four orders of magnitude, DNP-L-serine being the most, DNP-proline the least potent inhibitor. In addition to DNP analogues a large number (2074) of drugs and other compounds were tested for their ability to compete with DNP for the binding site of IgE(aDNP). At the concentrations used for screening 59% of the compounds had no significant inhibition; 19% inhibited the binding of IgE(aDNP) more than 50%. Several families of compounds (tetracyclines, polymyxines, phenotiazines, salicylates and quinones) of effective competitors were found. Within these families change in the functional groups attached to the "family stem" had major effects on the affinity of ligand binding. The occurrence frequencies of interactions of ligands with IgE(aDNP) is in good agreement with a semi-empirical model for multispecific antibody-ligand interactions.
Mol Immunol 1991 Jun
PMID:Mechanism of allergic cross-reactions--I. Multispecific binding of ligands to a mouse monoclonal anti-DNP IgE antibody. 165 Apr 28

The antigenic sites on the major allergen from yellow mustard (Sinapis alba L.) seeds were studied using murine (BALB/c) monoclonal antibodies (mAb) and human IgE antibodies. Ten IgG1 (K) mAb from two fusions were analyzed. Competition and complementation studies performed with peroxidase labeled mAb reveal the existence of two main antigenic sites in Sin a I. All the described mAb failed to recognize the unordered carboxyamidomethylated polypeptide chains, with the single exception of 2B3, which binds the alkylated large chain. However, this mAB cannot react with the tetranitromethane-modified protein which retains the native conformation. This fact suggests that the only tyrosine of Sin a I, located in the large chain, may be part of a sequential epitope of the allergen. This chemical modification also alters the binding of the mAb 4A11 and 3F3 to the allergen, besides 2B3. The three mAb belong to the same complementation group. Specific IgE binding cannot be inhibited either by the large or small carboxyamidomethylated polypeptide chains, while the nitrated allergen shows a weaker inhibitory activity than the native Sin a I. 4A11, which is a tyrosine-dependent mAb, causes the greatest binding inhibition of the tested mAb on human IgE from atopic individuals, as determined from a reverse enzyme immunoassay, suggesting an important role played by tyrosine in the immunochemical recognition of Sin a I.
Mol Immunol 1990 Feb
PMID:Epitope mapping of the major allergen from yellow mustard seeds, Sin a I. 169 Aug 53

Studies were carried out in order to confirm and extend knowledge of the physico-chemical properties of an allergenic material found in the pollen of the olive tree (Olea europea). The sera from 88% of patients who were sensitive to olive pollen contained IgE that reacted with a 19,000 Mr component and many also reacted to a 17,000 Mr band as shown by SDS-PAGE immunoblotting. A monoclonal antibody (OL-1) produced to the 19,000 Mr component also reacted with the 17,000 Mr band, and with bands at 21,000 and 41,000 under non-reduced conditions. HPLC separation followed by SDS-PAGE and immunoblotting of the fractions indicated that the allergen fraction from which the 19,000 and 17,000 components were derived had a mol. wt between 50 and 60 kD. Isoelectricfocusing followed by immunoblotting and development with (OL-1) indicated heterogeneity of the allergen with respect to pI values. Two of the strongest components of the six identified which reacted with (OL-1) had pIs of about 5.0 and 6.0 confirming the published data. The study therefore showed that olive pollen contains a number of allergenic components, with various mol. wts and pI values, with some epitopes in common, which may in the native state be bound together or aggregated.
Mol Immunol 1990 Jul
PMID:Heterogeneity of a major allergen from olive (Olea europea) pollen. 169 44

Mast cells and basophils have been known to play a central role in allergic inflammation through the release of chemical mediators by cross-linkage of IgE receptors. The IgE receptor triggering and calcium ionophore A23187 have also been shown to induce gene expression and production of tumor necrosis factor (TNF) by rat basophilic leukemia cells. In the present study, we examined whether IgE receptor triggering could induce gene expression and production of TNF in rat lung tissue. The lung tissue released not only histamine but also cytotoxic activity on L929 cells 2 and 4 h after incubation with dinitrophenyl conjugated to ovalbumin (DNP-OVA) following passive sensitization with anti-DNP monoclonal rat IgE antibody, whereas neither DNP-OVA nor anti-DNP IgE antibody could induce the cytotoxic activity when used solely. Calcium ionophore A23187 also could induce both histamine release and cytotoxic activity. These activities induced by IgE receptor triggering, A23187, and lipopolysaccharide were completely neutralized by preincubation with anti-mouse TNF-rabbit serum, but not with normal rabbit serum. Northern blot analysis using cDNA probe of mouse TNF demonstrated expression of TNF gene as early as 2 h after IgE receptor triggering. These data demonstrating that IgE receptor triggering induced gene expression and production of TNF in lung tissue suggest the participation of TNF in the pathogenesis of late asthmatic response through its biologic activities such as the attraction and activation of neutrophils and eosinophils.
Am J Respir Cell Mol Biol 1990 Oct
PMID:Production of tumor necrosis factor with IgE receptor triggering from sensitized lung tissue. 169 98

Three analogous peptides mimicking the known primary structure of ovalbumin (OA) in the region 323-339 (namely, OA 323-339, OA 323-338 and OA 324-336) were manually synthesized by the Merrifield solid phase technique. The synthetic preparations were purified by gel filtration and ion exchange high performance liquid chromatographies. The sequence linearities were deduced from the amino acid composition prior to each stage of coupling and the amino acid sequence determination on the ultimate chain. OA 323-339 was conjugated to BSA, using carbodiimide activation of the carrier protein and the conjugated compound was further used for production of antibodies in rabbit. The results showed that the region OA 323-339 was immunogenic; it could give immunoprecipitates with rabbit anti-OA 323-339-BSA in crossed immunoelectrophoresis (CIE). It similarly could bind human specific IgE from serum pools from patients allergic to egg in crossed radio immunoelectrophoresis (CRIE). Quantitative precipitation inhibition and specific IgE inhibition were used for confirming the antigenic and allergenic activities of this region. The results led us to conclude that the region 323-339 of the OA molecule encompassed an allergenic and antigenic epitope which were recognized by human and rabbit B-cells.
Mol Immunol 1990 Sep
PMID:Antigenic and allergenic determinants of ovalbumin--III. MHC Ia-binding peptide (OA 323-339) interacts with human and rabbit specific antibodies. 169 19

Much of the literature on penicillin hypersensitivity is devoted to the identification of penicillin antigens rather than allergens. Human IgE-binding determinants on different penicillins have rarely been closely investigated with the view of defining fine structural allergenic features and differences. We have developed radioimmunoassays employing ampicillin, amoxicillin and ticarcillin solid phases for the detection of penicillin-reactive IgE antibodies. Quantitative hapten inhibition studies employed to identify IgE-binding regions on the penicillin molecules revealed a heterogeneous group of allergenic determinants consisting exclusively, or in part, of the alpha-aminobenzyl and benzyl side chain groups and the beta-lactam and thiazolidine rings of the penicillin nucleus.
Mol Immunol 1990 Nov
PMID:Identification of penicillin allergenic determinants that bind IgE antibodies in the sera of subjects with penicillin allergy. 170 Oct 26

The major cat allergen, Fel d I, was purified to homogeneity from cat dander extract by sequential mAb affinity chromatography and HPLC size exclusion. The purity and allergenic activity of the preparation was demonstrated by different techniques such as HPLC, RAST inhibition, skin prick tests and CIE/CRIE. Fel d I showed a mol. wt of about 35,000 by HPLC gel filtration and of 18,000 by SDS-PAGE, confirming that it is a non-covalently linked dimer. However, SDS-PAGE analysis under reducing conditions as well as labelling experiments with 14C-iodoacetamide of 2-ME-reduced Fel d I showed that each mol. wt 18,000 monomer is comprised of two covalently S-S bound polypeptides with apparent mol. wt. of 4000 (alpha-chain) and 14,000 (beta-chain). Reduction and alkylation of Fel d I obliterated most of its allergenic activity, as determined by RAST inhibition and immunoblotting, suggesting that most of the IgE-binding sites are conformational. On the other hand, treatment of Fel d I by N-glycanase under reducing and non-reducing conditions indicated the presence of N-linked oligosaccharides in the beta-chain. Carbohydrate analysis data of the whole Fel d I molecule showed the presence of a relatively high carbohydrate content (approximately 20%). RAST inhibition experiments of native and deglycosilated allergen suggest that most IgE epitopes are located in the protein moiety of the molecule. However, the deglycosilated allergen showed a 2-4 fold reduction in its inhibition capacity of RAST as compared to the native allergen, suggesting that carbohydrates could have some role in keeping the active conformation of those epitopes. The N-terminal amino acid sequence of the beta-chain (20 residues) and most of the alpha-chain (40 residues) were determined. Both chain sequences showed no homology with other known protein sequences.
Mol Immunol
PMID:Studies on the biochemical structure of the major cat allergen Felis domesticus I. 171 68

Stimulation of mast cells results in two opposing reactions, activation events that cause degranulation and desensitization events that inhibit mediator release. Previous studies of human lung mast cells and murine mast cells have suggested that desensitization resulted from events that negatively regulated free cytosolic calcium ([Ca2+]i) levels; the current studies suggest otherwise. Stimulation of purified human lung mast cells with anti-IgE demonstrated that histamine release had reached a maximum at a time (5 mins) when [Ca2+]i levels were still near their maximum elevation. While there was a slow return of [Ca2+]i levels to baseline (T1/2 = 7.8 min), this rate of return could not clearly account for the cessation of histamine release. The heterogeneity in this decay parameter was also calculated to be insufficient to account for the heterogeneity in the peak calcium response while heterogeneity in the cell surface IgE density could adequately account for the heterogeneity in calcium responses. Preincubation of mast cells with anti-IgE antibody without extracellular calcium did lead to a progressive loss of the subsequent [Ca2+]i response when calcium was added back to the reaction, but the rate of desensitization determined by this measure, T1/2 of 8 min, was slower than the rate determined by measuring the progressive inhibition of histamine release (T1/2 of 4.5 min). In addition, no correlation existed for the rate of desensitization as measured by histamine release and that measured by the peak calcium response. These data suggested that the extent of histamine release was not strictly controlled by regulation of free cytosolic calcium and that desensitization events measured by the progressive loss in histamine release and calcium response were also not strictly related.
Mol Immunol 1991 Jun
PMID:Single cell analysis of free cytosolic calcium changes in human lung mast cells--II. The relationship between desensitization and the cellular regulation of calcium changes. 171 45

Twelve monoclonal antibodies (mAb) were isolated that bound to six clusters of epitopes on the constant region of the epsilon chain of human IgE. Four of the mAb bound to the C epsilon 1 or early C epsilon 2 regions; three of these bound to the IgE myeloma protein PS and to serum IgE but not to the IgE myeloma protein ND. These mAb probably recognize an allotypic marker. Another mAb reacted with heat-denatured, but not native IgE. Four of the mAb failed to release histamine; the epitopes recognized by these mAb are in the C epsilon 1, C epsilon 2 and C epsilon 3-4 regions of IgE. Three of these non-histamine releasing mAb did not bind to IgE on the basophil surface. These mAb recognize epitopes in C epsilon 2 and C epsilon 3-4 that are not accessible when IgE is bound to its receptor. Four mAb inhibited IgE binding to basophils; two of these did not release histamine, and two others that bind to epitopes in the C epsilon 2-4 domain, released histamine and therefore blocked IgE binding by steric hindrance. Inhibition of IgE binding by different mAb suggest that the Fc epsilon RI and Fc epsilon RII bind to partly overlapping regions of the IgE molecule although the sites do not appear to be identical. A number of sites on C epsilon 1 and C epsilon 3-4 were accessible when IgE is bound to its basophil receptor. The data support the concept that only part of the Fc portion of IgE is hidden in the receptor and that portions of C epsilon 1-4 are accessible on the cell surface. These mAb should be useful in determining the domains of IgE that are critical for its biological activity.
Mol Immunol 1991 Jun
PMID:Monoclonal antibodies defining epitopes on human IgE. 171 47

Three monoclonal antibodies to human IgE are described. One of them recognizes an epitope located within a region of 76 amino acids that has been shown to contain the Fc epsilon RI binding site. That epitope is shown to be susceptible to heating and to alkylation of cysteines involved in inter heavy chain bonds, but not to their reduction alone. In addition, this monoclonal antibody, although having a high affinity for free IgE, is unable to bind Fc epsilon RI-linked IgE. Based on these results, we discuss the possibility that the antibody recognizes the Fc epsilon RI binding site of the IgE molecule.
Mol Immunol 1991 Aug
PMID:Monoclonal antibodies against human IgE. Identification of an epitope sharing properties with the high-affinity receptor binding site. 171 27


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