A conserved Streptococcus pyogenes extracellular cysteine protease cleaves human fibronectin and degrades vitronectin

• Published in: Microbial pathogenesis Vol. 15; no. 5; pp. 327 - 346
• Main Authors: Kapur, Vivek, Topouzis, Stavros, Majesky, Mark W., Li, Ling-Ling, Hamrick, Marcie R., Hamill, Richard J., Patti, Joseph M., Musser, James M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier India Pvt Ltd 01.11.1993; Elsevier
• Subjects: Alleles; Bacterial Proteins - metabolism; Bacteriology; Base Sequence; Biological and medical sciences; Cells, Cultured; Codon; Cysteine Endopeptidases - metabolism; Endothelium, Vascular - cytology; Extracellular Matrix - metabolism; extracellular matrix proteins; Fibronectins - metabolism; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Glycoproteins - metabolism; group A streptococci; Humans; Metabolism. Enzymes; Microbiology; molecular evolution; Molecular Sequence Data; multilocus enzyme electrophoresis; Phylogeny; Point Mutation; Sequence Alignment; Sequence Deletion; Sequence Homology, Nucleic Acid; Streptococcal Infections - microbiology; Streptococcal Infections - prevention & control; Streptococcus pyogenes; Streptococcus pyogenes - enzymology; Streptococcus pyogenes - genetics; Streptococcus pyogenes - isolation & purification; Streptococcus pyogenes - pathogenicity; Substrate Specificity; Vitronectin; extracellular matrix proteins; multilocus enzyme electrophoresis; molecular evolution; group A streptococci; Human; Enzyme; Cysteine endopeptidases; Cell adhesion molecule; Vitronectin; Glycoproteins; Dendrogram; Extracellular; Fibronectin; Streptococcaceae; Molecular evolution; Allele; Enzymatic activity; Proteolysis; Bacteria; Hydrolases; Micrococcales; Streptococcus pyogenes; Proteinases; Polymorphism
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1006/mpat.1993.1083

Streptococcus pyogenes secretes an extracellular cysteine protease that cleaves human interleukin 1β precursor to form biologically active IL 1β, a major cytokine mediating inflammation and shock. To further investigate the potential role of the cysteine protease in host-parasite interactions, the enzyme was purified to apparent homogeneity and tested for ability to degrade several human extracellular matrix proteins. Purified protease cleaved fibronectin, apparently at specific sites, and rapidly degraded vitronectin. In contrast, the protease did not have substantial activity against laminin. The cysteine protease also cleaved fibronectin from human umbilical vein endothelial cells grown in vitro. Allelic variation in the cysteine protease structural gene was studied in 67 strains expressing 39 M protein serotypes and five provisional M serologic types, and representing 50 phylogenetically distinct clones identified by multilocus enzyme electrophoresis. The gene is well conserved and allelic variation is due solely to accumulation of point mutations. Based on predicted amino acid sequences, one mature cysteine protease variant would be made by clones expressing serotypes M2, M3, M4, M5, M6, M9, M10, M11, M12, M14, M18, M22, M23, M25, M27, M41, M49, M56, M59, two provisional M types, and two clones non-typeable for M protein. Moreover, 33 of the 39 speB alleles identified encode one of three mature protease variants that differ from one another at only one or two amino acids clustered in a ten-amino acid region. All 39 alleles, and virtually all strains, encode a product that reacts with polyclonal antisera specific for purified cysteine protease. No compelling evidence was found for a primitive differentiation of the speB gene into two distinct classes, as has been proposed for M protein, opacity factor phenotype, and vir regulon architecture. The results demonstrate that the cysteine protease is well conserved in natural populations of S. pyogenes, provide additional evidence that this enzyme is involved in host-parasite interactions, and suggest that the protease plays a role in bacterial dissemination, colonization, and invasion, and inhibition of wound healing.