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Isotope Substitution Effects on the Magnetic Compass Properties of Cryptochrome-Based Radical Pairs: A Computational Study
[Image: see text] The biophysical mechanism of the magnetic compass sense of migratory songbirds is thought to rely on the photochemical reactions of flavin-containing radical pairs in cryptochrome proteins located in the birds’ eyes. A consequence of this hypothesis is that the effect of the Earth’...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2023
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9900586/ https://www.ncbi.nlm.nih.gov/pubmed/36669149 http://dx.doi.org/10.1021/acs.jpcb.2c05335 |
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author | Pažėra, Gediminas Jurgis Benjamin, Philip Mouritsen, Henrik Hore, P. J. |
author_facet | Pažėra, Gediminas Jurgis Benjamin, Philip Mouritsen, Henrik Hore, P. J. |
author_sort | Pažėra, Gediminas Jurgis |
collection | PubMed |
description | [Image: see text] The biophysical mechanism of the magnetic compass sense of migratory songbirds is thought to rely on the photochemical reactions of flavin-containing radical pairs in cryptochrome proteins located in the birds’ eyes. A consequence of this hypothesis is that the effect of the Earth’s magnetic field on the quantum yields of reaction products should be sensitive to isotopic substitutions that modify the hyperfine interactions in the radicals. In this report, we use spin dynamics simulations to explore the effects of (1)H → (2)H, (12)C → (13)C, and (14)N → (15)N isotopic substitutions on the functioning of cryptochrome 4a as a magnetic direction sensor. Two main conclusions emerge. (1) Uniform deuteration of the flavin chromophore appears to be the best way to boost the anisotropy of the magnetic field effect and to change its symmetry. (2) (13)C substitution of three of the 12 flavin carbons, in particular C4, C4a, and C8α, seems to be the best recipe for attenuating the anisotropy. These predictions should give insight into the factors that control the magnetic sensitivity once spectroscopic techniques are available for measuring magnetic field effects on oriented protein samples. |
format | Online Article Text |
id | pubmed-9900586 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-99005862023-02-07 Isotope Substitution Effects on the Magnetic Compass Properties of Cryptochrome-Based Radical Pairs: A Computational Study Pažėra, Gediminas Jurgis Benjamin, Philip Mouritsen, Henrik Hore, P. J. J Phys Chem B [Image: see text] The biophysical mechanism of the magnetic compass sense of migratory songbirds is thought to rely on the photochemical reactions of flavin-containing radical pairs in cryptochrome proteins located in the birds’ eyes. A consequence of this hypothesis is that the effect of the Earth’s magnetic field on the quantum yields of reaction products should be sensitive to isotopic substitutions that modify the hyperfine interactions in the radicals. In this report, we use spin dynamics simulations to explore the effects of (1)H → (2)H, (12)C → (13)C, and (14)N → (15)N isotopic substitutions on the functioning of cryptochrome 4a as a magnetic direction sensor. Two main conclusions emerge. (1) Uniform deuteration of the flavin chromophore appears to be the best way to boost the anisotropy of the magnetic field effect and to change its symmetry. (2) (13)C substitution of three of the 12 flavin carbons, in particular C4, C4a, and C8α, seems to be the best recipe for attenuating the anisotropy. These predictions should give insight into the factors that control the magnetic sensitivity once spectroscopic techniques are available for measuring magnetic field effects on oriented protein samples. American Chemical Society 2023-01-20 /pmc/articles/PMC9900586/ /pubmed/36669149 http://dx.doi.org/10.1021/acs.jpcb.2c05335 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Pažėra, Gediminas Jurgis Benjamin, Philip Mouritsen, Henrik Hore, P. J. Isotope Substitution Effects on the Magnetic Compass Properties of Cryptochrome-Based Radical Pairs: A Computational Study |
title | Isotope Substitution
Effects on the Magnetic Compass
Properties of Cryptochrome-Based Radical Pairs: A Computational Study |
title_full | Isotope Substitution
Effects on the Magnetic Compass
Properties of Cryptochrome-Based Radical Pairs: A Computational Study |
title_fullStr | Isotope Substitution
Effects on the Magnetic Compass
Properties of Cryptochrome-Based Radical Pairs: A Computational Study |
title_full_unstemmed | Isotope Substitution
Effects on the Magnetic Compass
Properties of Cryptochrome-Based Radical Pairs: A Computational Study |
title_short | Isotope Substitution
Effects on the Magnetic Compass
Properties of Cryptochrome-Based Radical Pairs: A Computational Study |
title_sort | isotope substitution
effects on the magnetic compass
properties of cryptochrome-based radical pairs: a computational study |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9900586/ https://www.ncbi.nlm.nih.gov/pubmed/36669149 http://dx.doi.org/10.1021/acs.jpcb.2c05335 |
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