Electrochemical sensing of interaction of anterior gradient-2 protein with peptides at a charged interface

Anterior gradient-2 protein (AGR2) is overexpressed in many human cancers, and this protein presents a novel promising cancer biomarker. We show significant progress in understanding of the electric field effects on AGR2-peptides complexes using constant current chronopotentiometric stripping (CPS) analysis. Surface-attached AGR2-peptide complexes can be disintegrated as a result of their exposure to negative potentials. By controlling the exposure time and temperature, peaks of weakly bound non-specific complexes can be discriminated from tightly bound specific complexes. Using CPS analysis we found that mutant E60A-AGR2 forms weaker complex with peptide aptamer in comparison to wild type AGR2. These data highlight the utility of this method for studying real-time dynamics of surface-attached protein-peptide complexes.