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

Abstract

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 nonspecific 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.