title: Binding of plasminogen to Neisseria meningitidis and Neisseria gonorrhoeae and formation of surface-associated plasmin.
abstract: Forty-two strains of Neisseria meningitidis and 17 of Neisseria gonorrhoeae were tested for their ability to interact with 125I-labeled Glu-plasminogen. All strains tested reacted substantially with plasminogen, resulting in uptake values of 20%-48%. Scatchard analysis with selected N. meningitidis strains demonstrated a dual-phase receptor interaction, one more avid receptor with a Kd of 50 nM and 3000-6000 receptors per bacterium and a second receptor with a Kd of 200 nM and 10,000-20,000 receptors per bacterium. Plasminogen uptake could be completely eliminated by low concentrations of epsilon-aminocaproic acid, suggesting that the lysine binding sites on the plasminogen molecule are involved in the receptor-ligand interaction. The binding of plasminogen to the bacterial receptor facilitates the tissue-type plasminogen activator-mediated conversion to Glu-plasmin, which also modifies itself to the Lys form. Receptor-associated plasmin is enzymatically active, monitored as a breakdown of the chromogenic substrate S-2251, and retains its activity in the presence of naturally occurring inhibitors in plasma.
authors.affiliation: Department of Clinical Microbiology, Karolinska Hospital, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Ullberg
authors.forename: P
authors.initials: P
authors.lastname: Kuusela
authors.forename: B E
authors.initials: BE
authors.lastname: Kristiansen
authors.forename: G
authors.initials: G
authors.lastname: Kronvall
mesh_terms: D007611:Aprotinin / Q000378:metabolism; D001667:Binding, Competitive; D002353:Carrier State / Q000382:microbiology; D005341:Fibrinolysin / Q000096:biosynthesis* / Q000378:metabolism; D006069:Gonorrhea / Q000382:microbiology; D006801:Humans; D008589:Meningococcal Infections / Q000382:microbiology; D009344:Neisseria gonorrhoeae / Q000378:metabolism*; D009345:Neisseria meningitidis / Q000378:metabolism*; D010958:Plasminogen / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator
chemical_list: C524898:PLAUR protein, human; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D010958:Plasminogen; D007611:Aprotinin; D005341:Fibrinolysin