The extracellular matrix proteins laminin and fibronectin contain binding domains for human plasminogen and tissue plasminogen activator

T L Moser, J J Enghild, S V Pizzo, M S Stack

    Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

    Abstract

    This study describes the binding of plasminogen and tissue-type plasminogen activator (t-PA) to the extracellular matrix proteins fibronectin and laminin. Plasminogen bound specifically and saturably to both fibronectin and laminin immobilized on microtiter wells, with Kd(app) values of 115 and 18 nM, respectively. Limited proteolysis by endoproteinase V8 coupled with ligand blotting analysis showed that both plasminogen and t-PA preferentially bind to a 55-kDa fibronectin fragment and a 38-kDa laminin fragment. Amino acid sequence analysis demonstrated that the 5-kDa fragment originates with the fibronectin amino terminus whereas the laminin fragment was derived from the carboxyl-terminal globular domain of the laminin A chain. Ligand blotting experiments using isolated plasminogen domains were also used to identify distinct regions of the plasminogen molecule involved in fibronectin and laminin binding. Solution phase fibronectin binding to immobilized plasminogen was mediated primarily via lysine binding site-dependent interactions with plasminogen kringles 1-4. Lysine binding site-dependent binding of soluble laminin to immobilized plasminogen kringles 1-5 as well as an additional lysine binding site-independent interaction between mini-plasminogen and the 38-kDa laminin A chain fragment were also observed. These studies demonstrate binding of plasminogen and tissue-type plasminogen activator to specific regions of the extracellular matrix glycoproteins laminin and fibronectin and provide further insight into the mechanism of regulation of plasminogen activation by components of the extracellular matrix.
    Original languageEnglish
    JournalJournal of Biological Chemistry
    Volume268
    Issue25
    Pages (from-to)18917-23
    Number of pages6
    ISSN0021-9258
    Publication statusPublished - 1993

    Keywords

    • Amino Acid Sequence
    • Binding Sites
    • Enzyme-Linked Immunosorbent Assay
    • Fibronectins
    • Humans
    • Laminin
    • Molecular Sequence Data
    • Peptide Fragments
    • Plasminogen
    • Sequence Analysis
    • Serine Endopeptidases
    • Tissue Plasminogen Activator
    • Trypsin

    Fingerprint

    Dive into the research topics of 'The extracellular matrix proteins laminin and fibronectin contain binding domains for human plasminogen and tissue plasminogen activator'. Together they form a unique fingerprint.

    Cite this