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Complement research experienced a renaissance with the discovery of a third activation route, the lectin pathway. We developed a unique model of total lectin pathway deficiency, a mouse strain lacking mannan-binding lectin-associated serine protease-2 (MASP-2), and analyzed the role of MASP-2 in two models of postischemic reperfusion injury (IRI). In a(More)
The complement system plays a key role in host defense against pneumococcal infection. Three different pathways, the classical, alternative and lectin pathways, mediate complement activation. While there is limited information available on the roles of the classical and the alternative activation pathways of complement in fighting streptococcal infection,(More)
In bee venom phospholipase A2, histidine-34 probably functions as a Brønsted base to deprotonate the attacking water. Aspartate-64 and tyrosine-87 form a hydrogen bonding network with histidine-34. We have prepared mutants at these positions and studied their kinetic properties. The mutant in which histidine-34 is changed to glutamine is catalytically(More)
The molecular and cellular mechanisms controlling Ab isotype selection following encounter of a given Ag are still unclear, although the regulatory role of cytokines is established. In the present study we explored the possibility that the nonimmunologic interaction of an allergen with cells of the innate immune system might result in a release of mediators(More)
BACKGROUND Two hybridomas, which secrete human monoclonal antibodies of IgG4 isotype specific for the main bee venom antigen/allergen phospholipase A2, were generated. The antigenic determinants recognized by these antibodies were mapped and compared with the binding sites of murine monoclonal and human polyclonal antibodies raised against the same antigen.(More)
The present study identifies the phosphorylation sites of the 85-kDa cytosolic phospholipase A2 (cPLA2) in human platelets and HeLa cells. Tryptic digests of 32P-phosphorylated and -immunoprecipitated cPLA2 were analyzed by microbore high performance liquid chromatography and two-dimensional phosphopeptide mapping against synthetic phosphopeptide standards.(More)
Aspergillus fumigatus secretes an 18-kDa nonglycosylated IgE-binding protein. This protein was previously shown to be a ribotoxin, like alpha-sarcin and mitogillin. A 686-bp long A. fumigatus cDNA encoding an 18-kDa ribotoxin was cloned and expressed in Escherichia coli as a fusion protein with six adjacent histidines (rAsp f I/a). rAsp f I/a was purified(More)
The T cell-independent antibody response to polysaccharide antigen (Ag) is believed to result from their inability to bind major histocompatibility complex (MHC) restriction elements. However, recent studies using glycosylated analogues of known immunogenic peptides revealed that glycopeptides can interact with MHC molecules and are able to elicit specific(More)
Bee venom phospholipase A2 (BV-PLA2) is a hydrolytic enzyme that specifically cleaves the sn-2 acyl bond of phospholipids at the lipid/water interface. The same enzyme is also believed to be responsible for some systemic anaphylactic reactions in bee venom sensitized individuals. To study the structure/function relationships of this enzyme and to define the(More)
Ras proteins serve as critical relays in signal transduction pathways that control growth and differentiation and must undergo posttranslational modifications before they become functional. While it is established that farnesylation is necessary for membrane binding and cellular functions of all Ras proteins, the significance of palmitoylation is unclear.(More)