title: Degradation of connective tissue proteins by serine proteases from Streptococcus pneumoniae.
abstract: The proteolytic activity of pneumococcal culture supernatants was investigated. Phenylmethylsulfonyl fluoride and diisopropylfluorophosphate inhibited the proteolytic activity by 94% indicating that the enzymes are serine proteases. Zymogram analysis with inhibitors utilizing a non-denaturing gelatin substrate gel revealed two classes of serine proteases; one sensitive to calcium chelators and one resistant. Enzymes from the culture supernatant cleaved fibronectin, fibrinogen, elastin, and laminin; whereas bovine albumin, and the human immunoglobulins, IgG, IgM, and IgA, were not cleaved. These results indicate that pneumococci produce previously unrecognized serine proteases that degrade several tissue and blood proteins.
authors.affiliation: Veterans Administration Medical Center, Research Service, Memphis, TN 38104.
authors.forename: H S
authors.initials: HS
authors.lastname: Courtney
mesh_terms: D002845:Chromatography; D003238:Connective Tissue; D017886:Durapatite; D004549:Elastin / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005340:Fibrinogen / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D006882:Hydroxyapatites; D007136:Immunoglobulins; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D007797:Laminin / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D013296:Streptococcus pneumoniae / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D005353:Fibronectins; D006882:Hydroxyapatites; D007136:Immunoglobulins; D007527:Isoenzymes; D007797:Laminin; D015842:Serine Proteinase Inhibitors; D005340:Fibrinogen; D004549:Elastin; D017886:Durapatite; D012697:Serine Endopeptidases