Year: 2022
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide The non-native oxidation of horse heart myoglobin with hydrogen peroxide produces compound II which autoreduces by utilizing an internal oxidation site. Here, we utilize full UV–visible time-dependent kinetics with global kinetic singular value decomposition analysis to explore the mechanism and uncover more detail about the high-valent heme spectral features. By varying the hydrogen peroxide and myoglobin concentration, we were able to uncover more detailed spectra of myoglobin compound II and the autoreduction rate under several different pH conditions. The compound II spectra demonstrate pH-dependent features with an inflection point around pH 5.7 ± 0.1. The rate of autoreduction of compound II, k 2, increases with lower pH with a half-power proton dependence and no indication of a p K a > 3.9 ± 0.2, indicating that the autoreduction is still dependent on the protonation of the ferryl oxo species. The k 2 also demonstrates both hydrogen peroxide and myoglobin dependency. At myoglobin concentrations greater than 6.6 μM, the k 2 is myoglobin-independent, but for lower concentrations, a pH-sensitive concentration dependence is seen.
Source: ACS Omega
Institution: Xavier University of Louisiana
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,250
Awards: BUILD at Xavier, Project Pathways II, BUILD at Xavier, Project Pathways II, Xavier RCMI Center for Cancer Research , BUILD at Xavier, Project Pathways II, Exploring the protein structural features which regulate myoglobin's proton transfer dependent high-valent auto-reduction, The RCMI Center for Cancer and Health Disparities Research
OpenAlex ID: W4283012002