Related Experiment Video
Updated: Apr 8, 2026
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Peptide Fragments of Odin-Sam1: Conformational Analysis and Interaction Studies with EphA2-Sam
Flavia A Mercurio1, Concetta Di Natale2,3, Luciano Pirone4
1Institute of Biostructures and Bioimaging, National Research Council, Via Mezzocannone 16, 80134, Naples (Italy).
Abstract:
Odin is a protein belonging to the ANKS family, and has two tandem Sam domains. The first, Odin-Sam1, binds to the Sam domain of the EphA2 receptor (EphA2-Sam); this interaction could be crucial for the regulation of receptor endocytosis and might have an impact on cancer. Odin-Sam1 associates with EphA2-Sam by adopting a "mid-loop/end-helix" model. In this study three peptide sequences, encompassing the mid-loop interacting portion of Odin-Sam1 and its C-terminal α5 helix, were designed. Their conformational properties were analyzed by CD and NMR. In addition, their abilities to interact with EphA2-Sam were investigated by SPR studies. The peptides adopt a predominantly disordered state in aqueous buffer, but a higher helical content is evident in the presence of the cosolvent trifluoroethanol. Dissociation constants towards EphA2-Sam were in the high micromolar range. The structural findings suggest further routes for the design of potential anti-cancer therapeutics as inhibitors of EphA2-Sam heterotypic interactions.
Insights
Researchers studied Odin protein interactions with EphA2 receptor. Designed peptides targeting this interaction show potential for developing new anti-cancer therapeutics by inhibiting EphA2 signaling.
Area of Science:
- Molecular Biology
- Protein Interactions
- Cancer Research
Background:
- Odin, an ANKS family protein, possesses tandem Sam domains crucial for cellular processes.
- The Odin-Sam1 domain interacts with the EphA2 receptor Sam domain (EphA2-Sam), potentially regulating receptor endocytosis.
- This interaction is implicated in cancer progression, highlighting its therapeutic relevance.
Purpose of the Study:
- To investigate the structural and binding properties of peptides derived from the Odin-Sam1 domain.
- To explore the potential of these peptides as inhibitors of the Odin-Sam1/EphA2-Sam interaction for anti-cancer drug development.
Main Methods:
- Design and synthesis of three peptide sequences based on Odin-Sam1's EphA2-binding region.
- Circular Dichroism (CD) and Nuclear Magnetic Resonance (NMR) spectroscopy to analyze peptide conformation.
- Surface Plasmon Resonance (SPR) to quantify the binding affinity of peptides to EphA2-Sam.
Main Results:
- Peptides exhibited a predominantly disordered structure in aqueous buffer, with increased helical content in trifluoroethanol.
- Binding studies revealed high micromolar dissociation constants for peptide interactions with EphA2-Sam.
- Structural and binding data provide insights into the Odin-Sam1/EphA2-Sam interaction mechanism.
Conclusions:
- The designed peptides interact with EphA2-Sam, albeit with moderate affinity.
- These findings support the development of novel anti-cancer therapeutics targeting EphA2-Sam heterotypic interactions.
- Further optimization of peptide design could lead to more potent inhibitors.
