TY - JOUR
T1 - Magnetic circular dichroism of hemoproteins with in situ control of electrochemical potential: “MOTTLE”
AU - Marritt, Sophie
AU - Van Wonderen, Jessica
AU - Cheesman, Myles
AU - Butt, Julea
PY - 2006
Y1 - 2006
N2 - Hemoproteins have been recognized for nearly a century and are ubiquitous components of cellular organisms. Despite our familiarity with these proteins, defining the functional role of a given heme can still present considerable challenges. In this situation, magnetic circular dichroism (MCD) is a technique of choice because it has the capacity to define heme oxidation, spin, and ligation states in solution and at ambient temperature. Unfortunately, the resolving power of MCD rarely has been brought to bare on the intermediate redox states accessible to multiheme proteins. This is due in large part to the time-consuming procedure of magnetic field cycling required each time a sample is introduced into the magnet and the risk that control over, and knowledge of, the potential will be lost between sample preparation and spectral acquisition. Here we present a solution to this problem in the form of MCD-compatible optically transparent thin-layer electrochemistry (MOTTLE). MOTTLE defines redox behavior for cytochrome c in good agreement with the literature. In addition, MOTTLE reproduces the redox-driven transformation of heme ligand sets reported for cytochrome bd. Thus, MOTTLE provides a robust analytical tool for the dissection of heme properties with resolution across the electrochemical potential domain.
AB - Hemoproteins have been recognized for nearly a century and are ubiquitous components of cellular organisms. Despite our familiarity with these proteins, defining the functional role of a given heme can still present considerable challenges. In this situation, magnetic circular dichroism (MCD) is a technique of choice because it has the capacity to define heme oxidation, spin, and ligation states in solution and at ambient temperature. Unfortunately, the resolving power of MCD rarely has been brought to bare on the intermediate redox states accessible to multiheme proteins. This is due in large part to the time-consuming procedure of magnetic field cycling required each time a sample is introduced into the magnet and the risk that control over, and knowledge of, the potential will be lost between sample preparation and spectral acquisition. Here we present a solution to this problem in the form of MCD-compatible optically transparent thin-layer electrochemistry (MOTTLE). MOTTLE defines redox behavior for cytochrome c in good agreement with the literature. In addition, MOTTLE reproduces the redox-driven transformation of heme ligand sets reported for cytochrome bd. Thus, MOTTLE provides a robust analytical tool for the dissection of heme properties with resolution across the electrochemical potential domain.
U2 - 10.1016/j.ab.2006.08.017
DO - 10.1016/j.ab.2006.08.017
M3 - Article
VL - 359
SP - 79
EP - 83
JO - Analytical Biochemistry
JF - Analytical Biochemistry
SN - 0003-2697
IS - 1
ER -