Iga Protease
Mostrando 13-24 de 98 artigos, teses e dissertações.
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13. Molecular polymorphism and epidemiology of Neisseria meningitidis immunoglobulin A1 proteases.
Neisseria meningitidis is one of several important bacterial pathogens that secrete a specific protease capable of cleaving human immunoglobulin A1 (IgA1) in the hinge region. To obtain further information on this putative virulence factor, we examined the IgA1 protease and iga gene region of 133 isolates of N. meningitidis assigned to 88 multilocus enzyme g
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14. Differential Susceptibility of Human IgA Immunoglobulins to Streptococcal IgA Protease
IgA protease, a proteolytic enzyme found in human saliva and colonic fluid, hydrolyzes human serum IgA immunoglobulins to yield Fabα and Fcα fragments. The enzyme is produced by organisms in the normal human microflora and can be purified from culture filtrates of the common human oral organism Streptococcus sanguis (American Type Culture Collection no. 10
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15. Production of immunoglobulin A protease by Streptococcus pneumoniae from animals.
Human isolates of Streptococcus pneumoniae tested by traditional immunochemical methods produce a protease that cleaves human immunoglobulin A1 (IgA1) into Fab and Fc fragments. The protease may be an important virulence factor, but studies of its pathogenetic significance have been hampered by lack of a suitable animal model. Since S. pneumoniae is a respir
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16. Immunoglobulin A1 protease production by Haemophilus influenzae and Streptococcus pneumoniae.
Bacterial strains of Haemophilus species and Streptococcus pneumoniae were examined for synthesis of the enzyme immunoglobulin A1 (IgA1) protease. Of 36 H. influenzae strains examined, 35 produced IgA1 protease; strains included all six capsular types, unencapsulated variants of types b and d, and untypable H. influenzae. Eight Haemophilus strains (non-H. in
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17. Immunoglobulin A protease activity of Ureaplasma urealyticum.
All of 14 serotype standards and 34 of 35 wild-type strains of Ureaplasma urealyticum isolated from humans demonstrated an immunoglobulin A (IgA) protease activity. This activity degraded radiolabeled human IgA including IgA1 but not IgG or azocasein. The IgA fragments were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by ra
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18. Cleavage of immunoglobulin G (IgG) and IgA around the hinge region by proteases from Serratia marcescens.
Seven clinical and two nonclinical isolates of Serratia marcescens were examined for their ability to produce extracellular enzymes that cleave immunoglobulin G (IgG) and IgA molecules. All seven clinical isolates excreted a large amount of a 56-kilodalton (kDa) protease (56K protease) and small amounts of a 60-kDa and a 73-kDa protease (60K and 73K protease
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19. Antigenic heterogeneity of immunoglobulin A1 proteases from encapsulated and non-encapsulated Haemophilus influenzae.
Indirect evidence suggests that immunoglobulin A1 (IgA1) proteases may be factors in the pathogenesis of certain infectious diseases, including meningitis, gonorrhoea, and destructive periodontitis. Bacterial IgA1 proteases are therefore potential candidates as vaccines. In this study, IgA1 proteases from 166 clinical isolates and reference strains of Haemop
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20. Pathogenic Species of the Genus Haemophilus and Streptococcus pneumoniae Produce Immunoglobulin A1 Protease
Thirty-seven strains of the genus Haemophilus and five strains of Streptococcus pneumoniae were examined for their ability to produce extracellular enzyme that cleaves immunoglobulin molecules. All strains of H. influenzae, H. aegyptius, and S. pneumoniae elaborated enzyme that selectively cleaved human immunoglobulin A1 (IgA1) myeloma proteins but was inact
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21. Immunoglobulin A1 protease types of Neisseria gonorrhoeae and their relationship to auxotype and serovar.
Immunoglobulin A1 (IgA1) proteases are extracellular bacterial proteolytic enzymes which correlate with virulence in several species of human pathogens. We report that Neisseria gonorrhoeae produced two distinct types of IgA1 protease, each of which cleaved a different peptide bond in the hinge region of human IgA1. The type of IgA1 protease produced correla
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22. Nucleotide sequence homology between the immunoglobulin A1 protease genes of Neisseria gonorrhoeae, Neisseria meningitidis, and Haemophilus influenzae.
Isolated DNA fragments encoding the immunoglobulin A1 (IgA1) protease of Neisseria gonorrhoeae were used as hybridization probes to search for homologous sequences in whole cell DNA from Neisseria meningitidis and Haemophilus influenzae. Significant homology was detected. That the detected homology represented IgA1 protease-specific sequences was confirmed b
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23. Ecology and nature of immunoglobulin A1 protease-producing streptococci in the human oral cavity and pharynx.
The identity and proportional distribution of immunoglobulin A1 (IgA1) protease-producing streptococci in the oral and pharyngeal microflora were studied. A collection of 459 streptococcal strains, including reference strains of Streptococcus species, and fresh isolates from human dental plaque and buccal and pharyngeal mucosa were identified by biochemical
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24. New method that uses binding of immunoglobulin A to group A streptococcal immunoglobulin A Fc receptors for demonstration of microbial immunoglobulin A protease activity.
A new method is described for the detection of bacterial immunoglobulin A (IgA) protease which splits IgA into Fab and Fc fragments. The method takes advantage of a recent finding that receptors for IgA fragments occur commonly among type 4 group A streptococci. The bacterial preparation to be tested for protease activity was first incubated with radiolabele