Related Experiment Video
Updated: Jul 19, 2026
Extracellular Protein Microarray Technology for High Throughput Detection of Low Affinity Receptor-Ligand Interactions
Published on: January 7, 2019
Identification and characterization of a cell surface protein of Prevotella intermedia 17 with broad-spectrum binding
Fan Yu1, Divya Iyer, Cecilia Anaya
1Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298-0566, USA.
Abstract:
Prevotella intermedia binds and invades a variety of host cells. This binding is most probably mediated through cell surface proteins termed adhesins. To identify proteins binding to the host extracellular matrix (ECM) component, fibronectin, and study the molecular mechanism underlying bacterial colonization, we applied proteomic approaches to perform a global investigation of P. intermedia strain 17 outer membrane proteins. 2-DE followed by Far Western Blot analysis using fibronectin as a probe revealed a 29-kDa fibronectin-binding protein, designated here AdpB. The molecular identity of the protein was determined using PMF followed by a search of the P. intermedia 17 protein database. Database searches revealed the similarity of AdpB to multiple bacterial outer membrane proteins including the fibronectin-binding protein from Campylobacter jejuni. A recombinant AdpB protein bound fibronectin as well as other host ECM components, including fibrinogen and laminin, in a saturable, dose-dependent manner. Binding of AdpB to immobilized fibronectin was also inhibited by soluble fibronectin, laminin, and fibrinogen, indicating the binding was specific. Finally, immunoelectron microscopy with anti-AdpB demonstrated the cell surface location of the protein. This is the first cell surface protein with a broad-spectrum ECM-binding abilities identified and characterized in P. intermedia 17.
Insights
Prevotella intermedia utilizes a novel 29-kDa outer membrane protein, AdpB, to bind host extracellular matrix components like fibronectin. This discovery sheds light on bacterial colonization mechanisms and identifies a potential therapeutic target.
Area of Science:
- Microbiology
- Proteomics
- Bacterial Pathogenesis
Background:
- Prevotella intermedia adheres to and invades host cells, likely mediated by adhesins.
- Understanding bacterial colonization requires identifying proteins that bind host extracellular matrix (ECM).
Purpose of the Study:
- To identify outer membrane proteins of P. intermedia strain 17 that bind fibronectin.
- To investigate the molecular mechanisms of bacterial colonization by characterizing fibronectin-binding proteins.
Main Methods:
- Proteomic analysis of P. intermedia strain 17 outer membrane proteins.
- Two-dimensional electrophoresis (2-DE) followed by Far Western Blot analysis using fibronectin.
- Peptide mass fingerprinting (PMF) for protein identification.
- Recombinant protein expression and binding assays.
- Immunoelectron microscopy for protein localization.
Main Results:
- A 29-kDa fibronectin-binding protein, AdpB, was identified.
- Recombinant AdpB bound fibronectin, fibrinogen, and laminin in a saturable, dose-dependent manner.
- Adhesion was specific, as indicated by inhibition assays with soluble ECM components.
- Immunoelectron microscopy confirmed AdpB is located on the bacterial cell surface.
Conclusions:
- AdpB is the first identified P. intermedia cell surface protein with broad-spectrum ECM-binding capabilities.
- AdpB plays a significant role in P. intermedia's interaction with the host extracellular matrix.
- This protein represents a potential target for therapeutic interventions against P. intermedia infections.
Related Concept Videos
01:26Extracellular Matrix
01:21Matrix Proteoglycans and Glycoproteins
01:24Overview of Cell-Matrix Interactions