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Homology modeling of Mycoplasma pneumoniae enolase and its molecular interaction with human plasminogen
Vasunun Chumchua1, Natapol Pornputtapong, Chinae Thammarongtham
1Department of Biochemistry, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand.
Abstract:
Alpha (alpha)-enolase (e), a glycolytic enzyme, has an alternative role as a surface receptor of several bacteria mediating plasminogen (pg) binding. It is also recognized as a virulence factor of some pathogenic bacteria facilitating plasminogen activation and host cell invasion. A mycoplasmal alpha-enolase is also a plasminogen binding protein. Molecular interactions of enolase from Mycoplasma pneumoniae with host plasminogen would be useful for exploring the pathogen-host interaction. In an attempt to identify plasminogen binding sites of M. pneumoniae enolase, homology modeling and docking studies were conducted to obtain modeled structures of the M. pneumoniae enolase-plasminogen complex. The refined model was validated further by standard methods. Molecular docking revealed hydrogen bonding of eLys70-pgTyr50, eAsn165-pgThr66, eAla168-pgGlu21, eAsp17-pgLys70, and eAsn213-pgPro68/pgAsn69. Substantial decreases in accessible surface area (ASA) were observed and in concurrence with hydrogen bond pattern. These findings provide a detailed prediction of key residues that interact at the protein-protein interface. Our theoretical prediction is consistent with known biochemical data. The predicted interaction complex can be of great assistance in understanding structural insights, which is necessary to pathogen and host-component interaction. The ability of M. pneumoniae enolase to bind plasminogen may be indicative of an important role in invasion of this pathogen to host.
Insights
Mycoplasma pneumoniae enolase binds to human plasminogen, a key step in pathogen invasion. Molecular modeling identified specific binding sites and interactions, aiding understanding of host-pathogen dynamics.
Area of Science:
- Microbiology
- Structural Biology
- Biochemistry
Background:
- Alpha-enolase functions as a surface receptor in bacteria, binding plasminogen and aiding pathogen invasion.
- Mycoplasma pneumoniae enolase also binds plasminogen, suggesting a role in host-pathogen interactions.
Purpose of the Study:
- To identify plasminogen binding sites on Mycoplasma pneumoniae enolase.
- To model the molecular interactions between M. pneumoniae enolase and human plasminogen.
Main Methods:
- Homology modeling was used to create 3D structures of M. pneumoniae enolase.
- Molecular docking studies predicted the binding sites and interactions within the enolase-plasminogen complex.
- Standard validation methods confirmed the refined structural model.
Main Results:
- Molecular docking identified specific hydrogen bonds between enolase residues (e.g., eLys70) and plasminogen residues (e.g., pgTyr50).
- Significant decreases in accessible surface area correlated with the predicted hydrogen bond patterns.
- Key residues at the protein-protein interface were predicted, consistent with existing biochemical data.
Conclusions:
- The study provides a detailed prediction of the molecular interactions between M. pneumoniae enolase and plasminogen.
- These findings offer structural insights into pathogen-host interactions, crucial for understanding M. pneumoniae invasion mechanisms.
- The plasminogen-binding capability of M. pneumoniae enolase likely plays a significant role in the pathogen's ability to invade the host.
