Promoter effect of La3+ on the electrochemical reaction of microperoxidase-11

The effect of La3+ on the electrochemical behavior and structure of heme undecapeptide—microperoxidase-11 (MP-11)—in the aqueous solution was investigated using cyclic voltammetry, circular dichroism (CD) and UV–vis absorption spectrometry. It was found for the first time that La3+ would promote the electrochemical reaction of MP-11 at the glassy carbon (GC) electrode. This is mainly due to the fact that La3+ would induce more β-turn and α-helical conformations from the random coil conformation of MP-11 and increase the non-planarity of the heme.