Reeder, Brandon J and Svistunenko, Dimitri A and Wilson, Michael T (2024) Hell's Gate Globin-I from Methylacidiphilum infernorum Displays a Unique Temperature-Independent pH Sensing Mechanism Utililized a Lipid-Induced Conformational Change. International Journal of Molecular Sciences, 25 (12). p. 6794. DOI https://doi.org/10.3390/ijms25126794
Reeder, Brandon J and Svistunenko, Dimitri A and Wilson, Michael T (2024) Hell's Gate Globin-I from Methylacidiphilum infernorum Displays a Unique Temperature-Independent pH Sensing Mechanism Utililized a Lipid-Induced Conformational Change. International Journal of Molecular Sciences, 25 (12). p. 6794. DOI https://doi.org/10.3390/ijms25126794
Reeder, Brandon J and Svistunenko, Dimitri A and Wilson, Michael T (2024) Hell's Gate Globin-I from Methylacidiphilum infernorum Displays a Unique Temperature-Independent pH Sensing Mechanism Utililized a Lipid-Induced Conformational Change. International Journal of Molecular Sciences, 25 (12). p. 6794. DOI https://doi.org/10.3390/ijms25126794
Abstract
Hell's Gate globin-I (HGb-I) is a thermally stable globin from the aerobic methanotroph Methylacidiphilium infernorum. Here we report that HGb-I interacts with lipids stoichiometrically to induce structural changes in the heme pocket, changing the heme iron distal ligation coordination from hexacoordinate to pentacoordinate. Such changes in heme geometry have only been previously reported for cytochrome c and cytoglobin, linked to apoptosis regulation and enhanced lipid peroxidation activity, respectively. However, unlike cytoglobin and cytochrome c, the heme iron of HGb-I is altered by lipids in ferrous as well as ferric oxidation states. The apparent affinity for lipids in this thermally stable globin is highly pH-dependent but essentially temperature-independent within the range of 20-60 °C. We propose a mechanism to explain these observations, in which lipid binding and stability of the distal endogenous ligand are juxtaposed as a function of temperature. Additionally, we propose that these coupled equilibria may constitute a mechanism through which this acidophilic thermophile senses the pH of its environment.
Item Type: | Article |
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Uncontrolled Keywords: | Bacterial Proteins; Globins; Heme; Hydrogen-Ion Concentration; Lipids; Models, Molecular; Protein Conformation; Temperature |
Subjects: | Z Bibliography. Library Science. Information Resources > ZZ OA Fund (articles) |
Divisions: | Faculty of Science and Health Faculty of Science and Health > Life Sciences, School of |
SWORD Depositor: | Unnamed user with email elements@essex.ac.uk |
Depositing User: | Unnamed user with email elements@essex.ac.uk |
Date Deposited: | 22 Jul 2024 09:22 |
Last Modified: | 22 Jul 2024 09:23 |
URI: | http://repository.essex.ac.uk/id/eprint/38821 |
Available files
Filename: ijms-25-06794.pdf
Licence: Creative Commons: Attribution 4.0