title: Enhanced activation of bound plasminogen on Staphylococcus aureus by staphylokinase.
abstract: Activation of plasminogen (plg) to plasmin by the staphylococcal activator, staphylokinase (SAK), is effectively regulated by the circulating inhibitor, alpha2-antiplasmin (alpha2AP). Here it is demonstrated that intact Staphylococcus aureus cells and solubilized staphylococcal cell wall proteins not only protected SAK-promoted plg activation against the inhibitory effect of alpha2AP but also enhanced the activation. The findings suggest that the surface-associated plg activation by SAK may have an important physiological function in helping staphylococci in tissue dissemination. Amino acid sequencing of tryptic peptides originating from the 59-, 56- and 43-kDa proteins, isolated as putative plg-binding proteins, identified them as staphylococcal inosine 5'-monophosphate dehydrogenase, alpha-enolase, and ribonucleotide reductase subunit 2, respectively.
authors.affiliation: Department of Bacteriology and Immunology, The Haartman Institute, FIN-00014 University of Helsinki, Helsinki, Finland.
authors.forename: Tomi
authors.initials: T
authors.lastname: Mölkänen
authors.forename: Jaana
authors.initials: J
authors.lastname: Tyynelä
authors.forename: Jari
authors.initials: J
authors.lastname: Helin
authors.forename: Nisse
authors.initials: N
authors.lastname: Kalkkinen
authors.forename: Pentti
authors.initials: P
authors.lastname: Kuusela
mesh_terms: D000595:Amino Acid Sequence; D000933:Antifibrinolytic Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D004789:Enzyme Activation / Q000502:physiology; D005341:Fibrinolysin / Q000037:antagonists & inhibitors / Q000378:metabolism; D007168:IMP Dehydrogenase / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D008666:Metalloendopeptidases / Q000378:metabolism*; D008969:Molecular Sequence Data; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D010958:Plasminogen / Q000378:metabolism*; D012264:Ribonucleotide Reductases / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000378:metabolism*; D000979:alpha-2-Antiplasmin / Q000494:pharmacology*
chemical_list: D000933:Antifibrinolytic Agents; D001426:Bacterial Proteins; D000979:alpha-2-Antiplasmin; D010958:Plasminogen; D007168:IMP Dehydrogenase; D012264:Ribonucleotide Reductases; D005341:Fibrinolysin; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus; D010751:Phosphopyruvate Hydratase