RESUMO
BACKGROUND: C. pseudotuberculosis is an important animal pathogen that causes substantial economical loss in sheep and goat farming. Zoonotic infections in humans are rare, but when they occur they are often severe and difficult to treat. One of the most studied proteins from this bacterium, the secreted protein CP40 is being developed as a promising vaccine candidate and has been characterized as a serine protease. In this study we have investigated if CP40 is an endoglycosidase rather than a protease. RESULTS: CP40 does not show any protease activity and contains an EndoS-like family 18 of glycoside hydrolase (chitinase) motif. It hydrolyzes biantennary glycans on both human and ovine IgGs. CP40 is not a general chitinase and cannot hydrolyze bisecting GlcNAc. CONCLUSION: Taken together we present solid evidence for re-annotating CP40 as an EndoS-like endoglycosidase. Redefining the activity of this enzyme will facilitate subsequent studies that could give further insight into immune evasion mechanisms underlying corynebacterial infections in animals and humans.
Assuntos
Acetilglucosaminidase/metabolismo , Proteínas de Bactérias/metabolismo , Infecções por Corynebacterium/veterinária , Corynebacterium pseudotuberculosis/enzimologia , Doenças dos Ovinos/microbiologia , Acetilglucosaminidase/química , Acetilglucosaminidase/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Infecções por Corynebacterium/microbiologia , Corynebacterium pseudotuberculosis/química , Corynebacterium pseudotuberculosis/genética , Filogenia , OvinosRESUMO
AIM: The aim of this study was to identify and characterize EndoS-like enzymes in Streptococcus dysgalactiae subspecies dysgalactiae (SDSD). MATERIALS & METHODS: PCR, DNA sequencing, recombinant protein expression, lectin blot, ultra high performance liquid chromatography analysis and a chitinase assay were used to identify ndoS-like genes and characterize EndoSd. RESULTS: EndoSd were found in four SDSD strains. EndoSd hydrolyzes the chitobiose core of the glycan on IgG. The amino acid sequence of EndoSd is 70% identical to EndoS in S. pyogenes, but it has a unique C-terminal sequence. EndoSd secretion is influenced by the carbohydrate composition of the growth medium. CONCLUSION: Our findings indicate that IgG glycan hydrolyzing activity is present in SDSD, and that the activity can be attributed to the here identified enzyme EndoSd.