Energetics and dynamics of the proton shuttle of carbonic anhydrase II
(2023) In Cellular and Molecular Life Sciences 80(10).- Abstract
Human carbonic anhydrase II catalyzes the reversible reaction of carbon dioxide and water to form bicarbonate and a proton. His64-mediated proton shuttling between the active site and the bulk solvent is rate limiting. Here we investigate the protonation behavior of His64 as well as its structural and dynamic features in a pH dependent way. We derive two pK a values for His64, 6.25 and 7.60, that we were able to assign to its inward and outward conformation. Furthermore, we show that His64 exists in both conformations equally, independent of pH. Both conformations display an equal distribution of their two neutral tautomeric states. The life time of each conformation is short and both states display high flexibility within... (More)
Human carbonic anhydrase II catalyzes the reversible reaction of carbon dioxide and water to form bicarbonate and a proton. His64-mediated proton shuttling between the active site and the bulk solvent is rate limiting. Here we investigate the protonation behavior of His64 as well as its structural and dynamic features in a pH dependent way. We derive two pK a values for His64, 6.25 and 7.60, that we were able to assign to its inward and outward conformation. Furthermore, we show that His64 exists in both conformations equally, independent of pH. Both conformations display an equal distribution of their two neutral tautomeric states. The life time of each conformation is short and both states display high flexibility within their orientation. Therefore, His64 is never static, but rather poised to change conformation. These findings support an energetic, dynamic and solution ensemble-based framework for the high enzymatic activity of human carbonic anhydrase II.
(Less)
- author
- Raum, Heiner N. ; Fisher, Suzanne Zoë LU and Weininger, Ulrich
- organization
- publishing date
- 2023-10
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Enzyme catalysis, NMR spectroscopy, Protein dynamics, Proton shuttling, Proton transport
- in
- Cellular and Molecular Life Sciences
- volume
- 80
- issue
- 10
- article number
- 286
- pages
- 11 pages
- publisher
- Birkhäuser Verlag
- external identifiers
-
- pmid:37688664
- scopus:85170341638
- ISSN
- 1420-682X
- DOI
- 10.1007/s00018-023-04936-z
- language
- English
- LU publication?
- yes
- id
- b0245c2f-2166-4e47-978f-cb1cb7f18ff3
- date added to LUP
- 2023-10-09 16:56:47
- date last changed
- 2024-04-19 02:11:32
@article{b0245c2f-2166-4e47-978f-cb1cb7f18ff3,
abstract = {{<p>Human carbonic anhydrase II catalyzes the reversible reaction of carbon dioxide and water to form bicarbonate and a proton. His64-mediated proton shuttling between the active site and the bulk solvent is rate limiting. Here we investigate the protonation behavior of His64 as well as its structural and dynamic features in a pH dependent way. We derive two pK <sub>a</sub> values for His64, 6.25 and 7.60, that we were able to assign to its inward and outward conformation. Furthermore, we show that His64 exists in both conformations equally, independent of pH. Both conformations display an equal distribution of their two neutral tautomeric states. The life time of each conformation is short and both states display high flexibility within their orientation. Therefore, His64 is never static, but rather poised to change conformation. These findings support an energetic, dynamic and solution ensemble-based framework for the high enzymatic activity of human carbonic anhydrase II.</p>}},
author = {{Raum, Heiner N. and Fisher, Suzanne Zoë and Weininger, Ulrich}},
issn = {{1420-682X}},
keywords = {{Enzyme catalysis; NMR spectroscopy; Protein dynamics; Proton shuttling; Proton transport}},
language = {{eng}},
number = {{10}},
publisher = {{Birkhäuser Verlag}},
series = {{Cellular and Molecular Life Sciences}},
title = {{Energetics and dynamics of the proton shuttle of carbonic anhydrase II}},
url = {{http://dx.doi.org/10.1007/s00018-023-04936-z}},
doi = {{10.1007/s00018-023-04936-z}},
volume = {{80}},
year = {{2023}},
}