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Alpha-enolase resides on the cell surface of Mycoplasma fermentans and binds plasminogen

Amichai Yavlovich1, Hagai Rechnitzer, Shlomo Rottem

  • 1Department of Membrane and Ultrastructure Research, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.

Infection and Immunity
|October 17, 2007
PubMed

Insights

Mycoplasma fermentans surface alpha-enolase binds plasminogen (Plg), enhancing bacterial adherence and host cell invasion. This study identified alpha-enolase as the key Plg-binding protein on M. fermentans.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Biochemistry

Background:

  • Plasminogen (Plg) binding to Mycoplasma fermentans surfaces enhances bacterial adherence, Plg activation, and host cell internalization.
  • Identifying the specific M. fermentans protein responsible for Plg binding is crucial for understanding these interactions.

Purpose of the Study:

  • To isolate and identify the plasminogen (Plg) binding protein on the surface of Mycoplasma fermentans.
  • To confirm the presence and role of alpha-enolase as the major Plg binding protein.

Main Methods:

  • Affinity chromatography using a Plg-biotin complex to isolate the binding protein from M. fermentans membranes.
  • Mass spectrometry to identify the eluted protein.
  • Immunoblot analysis, immunochemical criteria, and immunoelectron microscopy to confirm surface localization and binding.

Main Results:

  • A approximately 50-kDa protein was isolated and identified as alpha-enolase by mass spectrometry.
  • Immunoblot and immunoelectron microscopy confirmed alpha-enolase presence on M. fermentans membranes.
  • Plg binding inhibited anti-alpha-enolase antibody binding, supporting alpha-enolase as the major Plg receptor.

Conclusions:

  • Mycoplasma fermentans surface alpha-enolase is a major plasminogen binding protein.
  • Surface-bound alpha-enolase contributes to M. fermentans adherence and host cell interactions.
  • Alpha-enolase plays a role beyond its glycolytic function in M. fermentans pathogenesis.

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