Electrochemically Monitoring the Acid and Acidic Urea-Induced Unfolding of Hemoglobin and Its Electrocatalytic Ability

Acid and acidic urea-induced unfolding of hemoglobin (Hb) was investigated using protein-film-based electrochemical method. The conformational transition of Hb was monitored through the change of direct electrochemical response of Hb. The heme groups in Hb detached from their native binding sites after pH < 4.0. Spectral experiments fully supported the results. Furthermore, the catalytic ability of lib was enhanced 15 times under the optimal unfolded conditions of pH 2.0 PBS containing 3.0 mol L-1 urea. The method contributes to understand the relationship between function and conformation of Hb, and provides possibility of manipulating protein function by controlling its conformation.