Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.36 (hyaluronidase)
4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Africanized honey bees and the wasp Polistes versicolor are common insects in Brazil; their venoms are composed of a complex mixture of components which present several biological activities. Stinging accidents are very frequent and are generally followed by important clinical reactions, and even deaths are not uncommon. In the present study, venom was extracted from Africanized honey bees and P. versicolor, and it was biochemically characterized and the antigenic cross-reactivity was investigated by Western blot analysis and specific IgE determination by ELISA in the sera of subjects allergic to each venom. The honey bee venom presented higher phospholipase A2 and hyaluronidase activities than P. versicolor venom, which in turn presented higher lipase, acid phosphatase and esterase activities. A high incidence of false-negatives was also observed during determinations of specific IgE for P. versicolor venom when the kits with venoms from wasps of temperate climates were used, suggesting that the diagnosis of allergy to neotropical wasp venom must take into consideration the clinical history and skin tests.
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PMID:Biochemical properties and study of antigenic cross-reactivity between Africanized honey bee and wasp venom. 808 40

The authors describe for the first time the Wasp/Mosquito syndrome. The allergenic cross-reactivity between Vespula wasp venom and mosquito extract and the reverse rest objectively on several criteria. The frequency of the association between sensibilization to Vespula wasp venom and mosquito: In 10 subjects who had specific IgE to Vespula wasp venom 3 also had mosquito-specific IgE (30%), but out of 11 subjects with positive mosquito-specific IgE 10 also were positive with Vespula wasp venom specific IgE (about 91%). Three observations were documented showing a clinical and biological relationship between sensitisation to mosquito and wasp venom. A first patient had an anaphylactic reaction after a dozen mosquito bites. The allergy assessment confirmed sensitisation to the mosquitos, but also to Vespides (wasp, hornet) venoms. A second patient had an anaphylactic reaction after a wasp sting in 1997. From that date, he had local reactions, indeed loco-regional, to mosquito bites. The allergy assessment confirmed the double sensibilization to mosquito and wasp venom. Finally, a third patient at first had local reactions, also loco-regional, to mosquito bites, then two systemic reactions after mosquito bites. A first allergy assessment, made exclusively to hymenoptera venoms (not to mosquitos), showed a sensitivity to wasp venom and the patient, by mistake, was desensitised to wasp venom, which did not prevent recurrence after mosquito bites. After a second time, the allergy assessment for hymenoptera and mosquito, confirmed a double sensitisation (mosquito and Vespula wasp). Indirect criteria such as parallel increase in specific IgEs to Vespula wasp venom and mosquito in a patient who was desensitised only to mosquito and who had not been re-stung by wasps. Finally on direct criteria, such as: The inhibition technique by CAP RAST, which was positive in two ways: Vespula wasp--specific IgE was inhibited by mosquito extract, and vice versa. Electrophoresis, which showed a protein common to Vespula wasp venom and mosquito extract of M.W. of the order or 42KD and isoelectric point between 4.5 and 5. An immunoblot study identified this common protein with a M.W. of 44KD which is the same as hyaluronidase.
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PMID:[The wasp/mosquito syndrome]. 1044 98

Allergic reactions to vespid stings are one of the major causes of IgE-mediated anaphylaxis. Vespa and Vespula venoms are closely related; Polistes venom is more distantly related and its allergens are less well studied. There is limited cross-reactivity between Polistes and the other vespid venoms because of differences in the epitopes on the allergen molecules. In this study, the major allergens of Polistes gallicus are isolated and characterized. P. gallicus venom contains four major allergens: phospholipase, antigen 5 (Ag5), hyaluronidase and protease that were characterized by mass spectrometry and specific binding to IgE. The complete amino acid sequence of Ag5 and the sequence of the N-terminal region of phospholipase were also determined. The alignment of Ag5 from P. gallicus (European species) and Polistes annularis (American species) shows an 85% identity that increases to 98% within the same subgenus. This could suggest the presence of specific epitopes on Ag5 molecule being the variations on the superficial loops. The features of the P. gallicus allergens could explain the partial cross-reactivity found between the American and European Polistes venoms, and suggest that the use of European Polistes venoms would improve the diagnostic specificity and the therapy of European patients and of North American patients sensitized by European Polistes.
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PMID:Characterization of the major allergens purified from the venom of the paper wasp Polistes gallicus. 1457 4

Novel approaches for the prevention of allergy are required, because of the inevitably increasing prevalence of allergic diseases during the last 30 years. Here, a recombinant chimeric protein, which comprises the whole amino acid sequences of three bee venom major allergens has been engineered and used in prevention of bee venom sensitization in mice. Phospholipase A2 (Api m 1), hyaluronidase (Api m 2) and melittin (Api m 3) fragments with overlapping amino acids were assembled in a different order in the Api m (1/2/3) chimeric protein, which preserved entire T cell epitopes, whereas B cell epitopes of all three allergens were abrogated. Accordingly, IgE cross-linking leading to mast cell and basophil mediator release was profoundly reduced in humans. Supporting these findings, the Api m (1/2/3) induced 100 to 1000 times less type-1 skin test reactivity in allergic patients. Treatment of mice with Api m (1/2/3) led to a significant reduction of specific IgE development towards native allergen, representing a protective vaccine effect in vivo. These results demonstrate a novel prototype of a preventive allergy vaccine, which preserves the entire T cell epitope repertoire, but bypasses induction of IgE against native allergen, and side effects related to mast cell/basophil IgE FcepsilonRI cross-linking in sensitized individuals.
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PMID:Prevention of allergy by a recombinant multi-allergen vaccine with reduced IgE binding and preserved T cell epitopes. 1620 31

Hyaluronidase (E.C. 3.2.1.35), one of the three major allergens of yellow jacket venom, is a glycoprotein of 45 kDa that is largely responsible for the cross-reactivity of wasp and bee venoms with sera of allergic patients. The asparagine-linked carbohydrate often appears to constitute the common IgE-binding determinant. Using a combination of MALDI MS and HPLC of 2-aminopyridine-labelled glycans, we found core-difucosylated paucimannosidic glycans to be the major species in the 43-45 kDa band of Vespula vulgaris and also in the corresponding bands of venoms from five other wasp species (V. germanica, V. maculifrons, V. pensylvanica, V. flavopilosa and V. squamosa). Concomitant peptide mapping of the V. vulgaris 43 kDa band identified the known hyaluronidase, Ves v 2 (SwissProt P49370), but only as a minor component. De novo sequencing by tandem MS revealed the predominating peptides to resemble a different, yet homologous, sequence. cDNA cloning retrieved a sequence with 58 and 59% homology to the previously known isoform and to the Dolichovespula maculata and Polistes annularis hyaluronidases. Close homologues of this new, putative hyaluronidase b (Ves v 2b) were also the major isoform in the other wasp venoms.
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PMID:The N-glycans of yellow jacket venom hyaluronidases and the protein sequence of its major isoform in Vespula vulgaris. 1621 50

Wasp venom from Vespula vulgaris contains three major allergens: Ves v 1, Ves v 2 and Ves v 5. Here, the cloning, expression, biochemical characterization and crystal structure determination of the hyaluronidase Ves v 2 from family 56 of the glycoside hydrolases are reported. The allergen was expressed in Escherichia coli as an insoluble protein and refolded and purified to obtain full enzymatic activity. Three N-glycosylation sites at Asn79, Asn99 and Asn127 were identified in Ves v 2 from a natural source by enzymatic digestions combined with MALDI-TOF mass spectrometry. The crystal structure of recombinant Ves v 2 was determined at 2.0 A resolution and reveals a central (beta/alpha)(7) core that is further stabilized by two disulfide bonds (Cys19-Cys308 and Cys185-Cys197). Based on sequence alignments and structural comparison with the honeybee allergen Api m 2, it is proposed that a conserved cavity near the active site is involved in binding of the substrate. Surface epitopes and putative glycosylation sites have been compared with those of two other major group 2 allergens from Apis mellifera (honeybee) and Dolichovespula maculata (white-faced hornet). The analysis suggests that the harboured allergic IgE-mediated cross-reactivity between Ves v 2 and the allergen from D. maculata is much higher than that between Ves v 2 and the allergen from A. mellifera.
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PMID:Structure of recombinant Ves v 2 at 2.0 Angstrom resolution: structural analysis of an allergenic hyaluronidase from wasp venom. 1669 86

Glycoproteins from honey-bee (Apis mellifera), such as phospholipase A2 and hyaluronidase, are well-known major bee-venom allergens. They carry N-linked oligosaccharide structures with two types of alpha1,3-fucosylation: the modification by alpha1,3-fucose of the innermost core GlcNAc, which constitutes an epitope recognized by IgE from some bee-venom-allergic patients, and an antennal Lewis-like GalNAcbeta1,4(Fucalpha1,3)GlcNAc moiety. We now report the cloning and expression of two cDNAs encoding the relevant active alpha1,3-FucTs (alpha1,3-fucosyltransferases). The first sequence, closest to that of fruitfly (Drosophila melanogaster) FucTA, was found to be a core alpha1,3-FucT (EC 2.4.1.214), as judged by several enzyme and biochemical assays. The second cDNA encoded an enzyme, most related to Drosophila FucTC, that was shown to be capable of generating the Le(x) [Galbeta1-4(Fucalpha1-3)GlcNAc] epitope in vitro and is the first Lewis-type alpha1,3-FucT (EC 2.4.1.152) to be described in insects. The transcription levels of these two genes in various tissues were examined: FucTA was found to be predominantly expressed in the brain tissue and venom glands, whereas FucTC transcripts were detected at highest levels in venom and hypopharyngeal glands. Very low expression of a third homologue of unknown function, FucTB, was also observed in various tissues. The characterization of these honey-bee gene products not only accounts for the observed alpha1,3-fucosylation of bee-venom glycoproteins, but is expected to aid the identification and subsequent down-regulation of the FucTs in insect cell lines of biotechnological importance.
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PMID:Towards abolition of immunogenic structures in insect cells: characterization of a honey-bee (Apis mellifera) multi-gene family reveals both an allergy-related core alpha1,3-fucosyltransferase and the first insect Lewis-histo-blood-group-related antigen-synthesizing enzyme. 1702 91

The major allergens of honeybee venom, hyaluronidase (Hyal) and phospholipase A2, can induce life-threatening IgE-mediated allergic reactions in humans. Although conventional immunotherapy is effective, up to 40% of patients develop allergic side effects including anaphylaxis and thus, there is a need for an improved immunotherapy. A murine monoclonal anti-Hyal IgG1 antibody (mAb 21E11), that competed for Hyal binding with IgEs from sera of bee venom allergic patients, was raised. The fragment of these IgG antibodies which bind to antigen (Fab) was produced and complexed (1:1) with Hyal. The crystal structure determination of Hyal/Fab 21E11 complex (2.6 A) enabled the identification of the Hyal-IgG interface which provides indirect information on the Hyal-IgE interaction (B-cell epitope). The epitope is composed of a linear array of nine residues (Arg138, His141-Arg148) located at the tip of a helix-turn-helix motive which protrudes away from the globular core and fits tightly into the deep surface pocket formed by the residues from the six complementarity determining regions (CDRs) of the Fab. The epitope is continuous and yet its conformation appears to be essential for Ab recognition, since the synthetic 15-mer peptide comprising the entire epitope (Arg138-Glu152) is neither recognized by mAb 21E11 nor by human IgEs. The structure of the complex provides the basis for the rational design of Hyal derivatives with reduced allergenic activity, which could be used in the development of safer allergen-specific immunotherapy.
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PMID:Identification of a B-cell epitope of hyaluronidase, a major bee venom allergen, from its crystal structure in complex with a specific Fab. 1737 40

Honeybee venom hyaluronidase (Api m 2) is a major glycoprotein allergen. Previous studies have indicated that recombinant Api m 2 expressed in insect cells has enzyme activity and IgE binding comparable with that of native Api m 2. In contrast, Api m 2 expressed in Escherichia coli does not. In this study, we characterized the carbohydrate side chains of Api m 2 expressed in insect cells, and compared our data with the established carbohydrate structure of native Api m 2. We assessed both the monosaccharide and the oligosaccharide content of recombinant Api m 2 using fluorophore-assisted carbohydrate electrophoresis and HPLC. To identify the amino acid residues at which glycosylation occurs, we digested recombinant Api m 2 with endoproteinase Glu-C and identified the fragments that contained carbohydrate by specific staining. Recombinant Api m 2 expressed in insect cells contains N-acetylglucosamine, mannose, and fucose, as well as trace amounts of glucose and galactose, and the oligosaccharide analysis is consistent with heterogeneous oligosaccharide chains consisting of two to seven monosaccharides. No sialic acid or N-acetylgalactosamine were detected. These results are similar to published data for native Api m 2, although some monosaccharide components appear to be absent in the recombinant protein. Analysis of proteolytic digests indicates that of the four candidate N-glycosylation sites, carbohydrate chains are attached at asparagines 115 and 263. Recombinant Api m 2 expressed in insect cells has enzymic activity and IgE binding comparable with the native protein, and its carbohydrate composition is very similar.
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PMID:Characterization of the N-glycans of recombinant bee venom hyaluronidase (Api m 2) expressed in insect cells. 1747 7

IgE-mediated type 1 hypersensitivity reactions to the bites of insects are a common cause of skin disease in horses. Insect bite hypersensitivity (IBH) is most frequently associated with bites of Culicoides spp. and occurs in all parts of the world where horses and Culicoides coexist. The main allergens that cause IBH are probably some of the abundant proteins in the saliva of Culicoides associated with blood feeding. Western blots of Culicoides proteins separated by 1D gel-electrophoresis detected strong IgE responses in all horses with IBH to antigens in protein extracts from wild caught Culicoides, but only weak responses to salivary antigens from captive bred C. nubeculosus which may reflect important differences among allergens from different species of Culicoides or differences between thorax and salivary gland antigens. 2D electrophoresis and mass spectrometry were used to identify several of the abundant proteins in the saliva of C. nubeculosus. These included maltase, members of the D7 family, and several small, basic proteins associated with blood feeding. The most frequently detected IgE-binding proteins were in a group of proteins with pI>8.5 and mass 40-50kDa. Mass spectrometry identified two of these allergenic proteins as similar to hyaluronidase and a heavily glycosylated protein of unknown function that have previously been identified in salivary glands of C. sonorensis.
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PMID:Identification of abundant proteins and potential allergens in Culicoides nubeculosus salivary glands. 1806 8


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