Protein Structure-sensitive Analysis by Normal Pulse Voltammetry

Earlier we showed that constant current chronopotentiometric stripping (CPS) at mercury-containing electrodes reflects changes in proteins, such as denaturation, single amino acid exchange or protein damage by physical and chemical agents. Here we attempted to compare performance of the galvanostatic CPS with the potentiostatic normal pulse voltammetry (NPV). We have found that repeated 50ms or longer NPV pulses denature the surface-attached protein. Using shorter pulses and adapting other NPV settings we have been able to obtain a good resolution of native (folded) and denatured (unfolded) bovine serum albumin. On the other hand, partial denaturation of the surface-attached native bovine serum albumin during the potential scanning may prevent detection of small conformational changes in the protein.