Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors present data concerning the state of the microflora of the nasopharynx in the immunization of adults and schoolchildren with the living influenza vaccine for oral administration. During the vaccinal process there occurred qualitative changes in the microbial pattern of the nasopharynx and a reduction in the level of the salivary lysozyme. The most pronounced changes were seen after the first vaccination, when the seeding efficiency of the pathogenic staphylococcus the E. coli and the Pr. mirabilis increased considerably. At the same time the incidence of isolation of the pathogenic staphylococcus, neisseria, and hemolytic streptococcus was decreased. The mentioned changes in the microbial flora directly depended on the dynamics of the survival of the vaccine influenza virus.
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PMID:[Condition of microflora of the nasopharynx in immunization with live influenza vaccine for oral administration]. 76 28

The crystal structure of the complex between neuraminidase from influenza virus (subtype N9 and isolated from an avian source) and the antigen-binding fragment (Fab) of monoclonal antibody NC41 has been refined by both least-squares and simulated annealing methods to an R-factor of 0.191 using 31,846 diffraction data in the resolution range 8.0 to 2.5 A. The resulting model has a root-mean-square deviation from ideal bond-length of 0.016 A. One fourth of the tetrameric complex comprises the crystallographic model, which has 6577 non-hydrogen atoms and consists of 389 protein residues and eight carbohydrate residues in the neuraminidase, 214 residues in the Fab light chain, and 221 residues in the heavy chain. One putative Ca ion buried in the neuraminidase, and 73 water molecules, are also included. A remarkable shape complementarity exists between the interacting surfaces of the antigen and the antibody, although the packing density of atoms at the interface is somewhat looser than in the interior of a protein. Similarly, there is a high degree of chemical complementarity between the antigen and antibody, mediated by one buried salt-link, two solvated salt-links and 12 hydrogen bonds. The antibody-binding site on neuraminidase is discontinuous and comprises five chain segments and 19 residues in contact, whilst 33 neuraminidase residues in eight segments have 899 A2 of surface area buried by the interaction (to a 1.7 A probe), including two hexose units. Seventeen residues in NC41 Fab lying in five of the six complementarity determining regions (CDRs) make contact with the neuraminidase and 36 antibody residues in seven segments have 916 A2 of buried surface area. The interface is more extensive than those of the three lysozyme-Fab complexes whose crystal structures have been determined, as judged by buried surface area and numbers of contact residues. There are only small differences (less than 1.5 A) between the complexed and uncomplexed neuraminidase structures and, at this resolution and accuracy, those differences are not unequivocal. The main-chain conformations of five of the CDRs follow the predicted canonical structures. The interface between the variable domains of the light and heavy chains is not as extensive as in other Fabs, due to less CDR-CDR interaction in NC41. The first CDR on the NC41 Fab light chain is positioned so that it could sterically hinder the approach of small as well as large substrates to the neuraminidase active-site pocket, suggesting a possible mechanism for the observed inhibition of enzyme activity by the antibody.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Refined crystal structure of the influenza virus N9 neuraminidase-NC41 Fab complex. 138 57

We examined the binding to foreign antigens and the expression of crossreactive idiotypes by a panel of 20 murine monoclonal autoantibodies encoded by V genes from the VH J558 family. 9 of 20 antibodies bound to foreign antigens such as bacterial polysaccharides, poly(Glu50, Tyr50), poly(Glu54,Lys37,Phe9), arsonate, and lysozyme, known to interact with antibodies encoded by genes from the VH J558 family. A high proportion of our panel of autoantibodies expressed crossreactive idiotypes originally borne by monoclonal rheumatoid factors, anti-Sm, and anti-DNA antibodies, all encoded by V genes from the VH J558 family. Some of these VH J558+ autoantibodies shared crossreactive idiotypes with VH J558+ antibodies directed against foreign antigens such as influenza virus hemagglutinin, poly(Glu60,Ala30,Tyr10), arsonate, and dextran. The implications of these findings are discussed with respect to the process of activation of self-reactive clones.
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PMID:Autoantibodies of various specificities encoded by genes from the VH J558 family bind to foreign antigens and share idiotopes of antibodies specific for self and foreign antigens. 244 98

Microtubule-disrupting drugs (nocodazole, colchicine) and cytochalasin D, which inhibits the polymerization of the actin microfilaments, were used to study the role of the cytoskeleton in protein secretion in the polarized Madin-Darby canine kidney (MDCK) epithelial cells. Two proteins were analyzed. The gp 80 glycoprotein complex, which in untreated cells is sorted into the apical pathway and lysozyme, which is released randomly at both cell surfaces in transfected MDCK cells. Our results show that cytochalasin D has no influence on the transport of the gp 80 complex and lysozyme to either cell surface. However, in the presence of nocodazole or colchicine the secretion of both proteins at the apical cell surface is reduced by 50% with a concomitant increase in the basolateral release. These data suggest that microtubules are necessary for an efficient secretion of proteins at the apical cell surface of MDCK cells. In regard to the yet unresolved discrepancy concerning the involvement of microtubules in the transport of membrane proteins to the apical surface of MDCK cells, our results are consistent with the data of Rindler et al. (Rindler, M. J., Ivanov, I. E., and Sabatini, D. D. (1987) J. Cell. Biol. 104, 231-241) who observed a nonpolarized delivery of the influenza virus hemagglutinin in the presence of nocodazole or colchicine.
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PMID:Microtubules are involved in the secretion of proteins at the apical cell surface of the polarized epithelial cell, Madin-Darby canine kidney. 277 9

Plasmids have been constructed in which promoters of 70-kDa heat-shock protein genes (hsp70) of human and Drosophila origin were linked to three different eukaryotic genes encoding human growth hormone (hGH), chicken lysozyme (cL) and a human influenza haemagglutinin (HA). Following transfection into widely divergent eukaryotic cells, the hybrid genes direct the transient, heat-regulated synthesis of the three proteins. hGH and cL are secreted into the medium. A human hsp70-hGH construct was used to establish stable mouse fibroblast lines that are capable of producing and secreting hGH at high levels following heat induction: hGH is secreted at a 500-1200-fold higher rate by heat-treated than by untreated cells.
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PMID:High-level, heat-regulated synthesis of proteins in eukaryotic cells. 356 12

We studied the antigen-presenting capacity of mouse L fibroblasts transfected with genes encoding Ia polypeptides of the major histocompatibility complex (MHC). These cells function as efficient antigen-presenting cells (APC) in stimulating peptide antigen-specific MHC-restricted proliferation of long-term T-cell lines, thus establishing the capacity of Ia-expressing L-cell transfectants to present antigens to apparently normal T cells. However, in contrast to splenic APC, L-cell transfectants fail to present native hen egg-white lysozyme to the same T cells. Since this result is similar to that obtained with physiologic APC pretreated to prevent antigen degradation, it suggests that L-cell transfectants, without such pretreatments, may be compromised in their ability to process native lysozyme. However, since such transfectant cells have been shown to present other complex polypeptides such as keyhole limpet hemocyanin, a random copolymer of glutamic acid, alanine, and tyrosine, and influenza virus neuraminidase, this observation suggests that protein antigens differ in the stringency of processing requirements.
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PMID:Ia-transfected L-cell fibroblasts present a lysozyme peptide but not the native protein to lysozyme-specific T cells. 387 53

Complete nucleotide sequence of the cloned full-length DNA copy of the influenza virus A (H1N1) neuraminidase gene has been determined. The predicted amino acid sequence is compared with sequences of neuraminidases from other influenza virus strains. A section of the neuraminidase is found to be homologous to the chicken lysozyme catalytic centre.
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PMID:[Synthesis, cloning and determination of the primary structure of a full-size DNA copy of the neuraminidase gene from influenza virus type A subtype H1N1]. 403 48

A total of 359 patients with acute pneumonia and 152 practically healthy subjects comprising the control group were examined. Immunofluorescence was used to investigate nasopharyngeal washings for detecting antigens of influenza and parainfluenza viruses, respiratory-syncytial virus, adenoviruses, whereas serological studies according to the hemagglutination delay test with diagnostic agents for detecting influenza A1, A2, B, types 1, 2 and 3 parainfluenza, and the complement fixation test were made to detect antibodies against adenoviruses. Serological (65%) and immunofluorescence (63%) studies revealed associations of different viruses: type 3 and 1 parainfluenza, respiratory-syncytial virus (73%) with adenoviruses, influenza B, A2, type 2 parainfluenza. Association of different bacteria was observed in 67% of patients: hemolytic staphylococcus (65%), hemolytic streptococcus (50%), pneumococci (45%), P. aeruginosa (40%), P. mirabilis (35%), E. coli (30%), enterococci (25%). Associations of 3-2 causative agents were predominant (53%). Marked decrease in the content of complement and beta-lysins, elevation of the level of lysozyme were observed in patients with viral-bacterial and viral pneumonias as compared to the same characteristics in patients with bacterial pneumonia and in control group subjects.
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PMID:[Viral-microbial associations and the function of humoral factors of natural immunity in acute pneumonia patients]. 652 59

A group of young people, totaling 1160 persons, was immunized annually with influenza inactivated chromatographic divaccine prepared from influenza viruses A (H1N1 +/- H3N2) for 3 years. Only in persons immunized once or twice direct correlation between the number of immunizations and their immunological effectiveness was observed. Repeated immunization produced no stimulating effect on the level of systemic humoral and secretory immunity. The innocuity of repeated vaccinations is substantiated by the absence of such effect on the somatic morbidity of the vaccinees and the levels of complement, lysozyme and beta-lysin in the blood serum.
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PMID:[Effect of repeated immunization with inactivated influenza vaccine on the formation of specific and nonspecific immunity factors]. 652 84

There are now several crystal structures of antibody Fab fragments complexed to their protein antigens. These include Fab complexes with lysozyme, two Fab complexes with influenza virus neuraminidase, and three Fab complexes with their anti-idiotype Fabs. The pattern of binding that emerges is similar to that found with other protein-protein interactions, with good shape complementarity between the interacting surfaces and reasonable juxtapositions of polar residues so as to permit hydrogen-bond formation. Water molecules have been observed in cavities within the interface and on the periphery, where they often form bridging hydrogen bonds between antibody and antigen. For the most part the antigen is bound in the middle of the antibody combining site with most of the six complementarity-determining residues involved in binding. For the most studied antigen, lysozyme, the epitopes for four antibodies occupy approximately 45% of the accessible surface area. Some conformational changes have been observed to accompany binding in both the antibody and the antigen, although most of the information on conformational change in the latter comes from studies of complexes with small antigens.
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PMID:Interactions of protein antigens with antibodies. 855 77


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