A case for myoglobin-macromolecular rate theory applied to pseudo peroxidase kinetics
Year: 2025
Type: article
Abstract: This study explores the well-known catalytic behavior of myoglobin as a pseudo-peroxidase by applying macromolecular rate theory (MMRT) to assess its temperature-dependent enzyme kinetics. While myoglobin is primarily recognized for its oxygen-binding properties in muscle tissues, with a characterized pseudo-peroxidase ability to catalyze the degradation of hydrogen peroxide in the presence of electron donors, the claim that myoglobin is actually a true peroxidase can be explored by analyzing the heat capacity changes (ΔCp‡) in the catalyzed reaction at different temperatures and fitting the results to the expanded Eyring equation (MMRT equation). This research uses the MMRT equation to compare myoglobin’s catalytic activity (a pseudo-peroxidase) with that of lactoperoxidase (a true peroxidase) and copper ions (a non-enzymatic catalyst) across a range of temperatures at pH 5, after which the biological catalysts are compared again at pH 7. By analyzing the ΔCp‡ of these catalysts, it was found that myoglobin exhibits a significant catalytic contribution at both pH levels, suggesting a structural/vibrational or some other relatively significant transition during the reaction. The study’s findings provide a new perspective into myoglobin’s enzymatic role in peroxide decomposition and highlight the utility of MMRT in quantifying the contribution of polypeptide chains in enzyme-catalyzed peroxidase reactions. Additionally, our research notes the pH-dependence of myoglobin’s catalytic efficiency compared to traditional peroxidases, offering implications for understanding its broader biological roles.
Source: PeerJ
DOI: 10.7717/peerj.19205
Authors: Collin Tuttle, Michael Hannesson, Amy Henrichsen, Lily Hainsworth, Camille Condie, Aj Whitesides, Archel Oren, Simeon Tanner, Benjamin Terry, Jacob Cannon, Jeremy Johansen, Alisha Bhatia, Daniel Scott
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,395
Funder: Utah Valley University
OpenAlex ID: W4409082044