A secreted streptococcal cysteine protease can cleave a surface-expressed M1 protein and alter the immunoglobulin binding properties.
Res Microbiol
; 149(8): 539-48, 1998 Sep.
Article
en En
| MEDLINE
| ID: mdl-9795991
Previous studies of recent clinical isolates of serotype M1 group A streptococci indicated that they display two patterns of non-immune human IgG subclass binding reactivity associated with their M1 protein. One group reacted with all four IgG subclasses (type IIo), while the second group expressed an M1 protein reacting preferentially with human IgG3 (type IIb). In this study, we have demonstrated that a cysteine protease, SpeB, present in culture supernatants of M1 serotype group A streptococcal isolates expressing type IIb IgG binding protein, can convert a recombinant Emm1 protein from a type IIo functional profile to a type IIb profile by removal of 24 amino acids from the N-terminus of the mature M1 protein. Furthermore, SpeB can convert bacteria expressing IgG binding proteins of the type IIo phenotype into those expressing type IIb proteins. The role of the cysteine protease as the central bacterial enzyme in this posttranslational modification event was confirmed by generation of an isogenic SpeB-negative mutant.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Streptococcus pyogenes
/
Proteínas de la Membrana Bacteriana Externa
/
Proteínas Bacterianas
/
Inmunoglobulina G
/
Cisteína Endopeptidasas
/
Proteínas Portadoras
/
Antígenos Bacterianos
Límite:
Humans
Idioma:
En
Revista:
Res Microbiol
Asunto de la revista:
MICROBIOLOGIA
Año:
1998
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Francia