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Plasminogen interaction and activation on Streptococcus mutans surface

L Urdaneta1, G Vanegas, G Premoli

  • 1Centro de Investigaciones Odontológicas, Facultad de Odontología, Universidad de Los Andes, Mérida, Venezuela.

Oral Microbiology and Immunology
|June 24, 2004
PubMed

Insights

Streptococcus mutans binds human plasminogen via lysine-binding sites. This binding enhances plasminogen activation, increasing the bacterium's virulence and proteolytic activity, suggesting a role in infection.

Area of Science:

  • Microbiology
  • Biochemistry
  • Molecular Biology

Background:

  • Pathogenic microorganisms can bind plasminogen, and its activation to plasmin contributes to virulence.
  • Streptococcus mutans is a significant oral pathogen implicated in various infections.

Purpose of the Study:

  • To investigate the interaction between Streptococcus mutans and human plasminogen.
  • To determine the mechanism of plasminogen binding and its functional consequences for S. mutans virulence.

Main Methods:

  • Studying the binding of human plasminogen and plasmin to S. mutans.
  • Investigating the role of lysine-binding sites using inhibitors like L-lysine and epsilon-aminocaproic acid.
  • Assessing the effect of S. mutans on plasminogen activation by tissue plasminogen activator and urokinase.
  • Analyzing proteolytic activity using zymogram analysis.

Main Results:

  • Streptococcus mutans effectively binds both human plasminogen and plasmin.
  • Plasminogen binding is mediated by lysine-binding sites, as evidenced by inhibition with L-lysine and epsilon-aminocaproic acid.
  • S. mutans enhances plasminogen activation by tissue plasminogen activator in a cell-concentration-dependent manner.
  • Zymogram analysis revealed that acquired plasmin activity is the predominant proteolytic activity in S. mutans.

Conclusions:

  • Streptococcus mutans acquires host plasminogen and plasmin, suggesting a mechanism for enhancing virulence.
  • The interaction involves specific lysine-binding sites on plasminogen.
  • Acquired proteolytic activity via plasmin may contribute to the infective process of S. mutans.

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