Electrochemical Study On The Redox Properties And Enzymatic Activities Of Myoglobin And Hemoglobin

The redox reactions and enzyme-like properties of myoglobin and hemoglobin were explored by the electrochemical theories and methods. The results were summarized as the following:(1) Myoglobin (Mb) , immobilized on glassy carbon electrode (GCE) surface by carrageenan, can transfer electron directly to electrode surface both in aqueous and aqueous-organic mixture solutions. Proteins entrapped in the carrageenan film undergo fast direct transfer-electronreactions, corresponding to Fe(III) + e→Fe(II). The E~0' are linearly dependent on solution pH (redox Bohr effect), indicating the electron transfer of Fe(III)/Fe(II) redox couple companied with the transfer of proton. Ultraviolet visible (UV-Vis) spectra suggest thatproteins keep their original conformation in the carrageenan films, and theconformation changes reversibly in a range of pH 3.0-11.0. The mechanisms for catalytic reduction of oxygen, peroxides, and dehalogenation of haloethanes, by proteins entrapped in carrageenan were also explored.(2) Hemoglobin was entrapped in thecarrageenan film undergo fast direct transfer-electron reactions in aqueous-organi solvents mixtures. The E~0' are linearly dependent on solution pH(redox Bohr effect), indicating the electron transfer of Fe(III)/Fe(II) redox couplecompanied with the transfer of proton.The mechanisms for catalytic reduction of oxygen, hperoxides, and dehalogenation of haloethanes by hemoglobin entrapped in carrageenan hydrogel were also explored.