Relativistic Interactions in the Radical Pair Model of Magnetic Field Sense in CRY-1 Protein ofArabidopsis thaliana

2009 ◽  
Vol 113 (44) ◽  
pp. 12276-12284 ◽  
Author(s):  
Artur F. Izmaylov ◽  
John C. Tully ◽  
Michael J. Frisch
Keyword(s):  
Magnetic Field ◽  
Radical Pair ◽  
Pair Model ◽  
Ofarabidopsis Thaliana

scholarly journals Light-dependent magnetoreception in birds: the crucial step occurs in the dark

2016 ◽  
Vol 13 (118) ◽  
pp. 20151010 ◽  
Author(s):  
Roswitha Wiltschko ◽  
Margaret Ahmad ◽  
Christine Nießner ◽  
Dennis Gehring ◽  
Wolfgang Wiltschko
Keyword(s):  
Magnetic Field ◽  
Flavin Adenine Dinucleotide ◽  
Radical Pair ◽  
Magnetic Compass ◽  
Radical Pairs ◽  
Intermittent Light ◽  
Pair Model ◽  
Dark Interval ◽  
Behavioural Experiments ◽  
The Magnetic Field

The Radical Pair Model proposes that the avian magnetic compass is based on spin-chemical processes: since the ratio between the two spin states singlet and triplet of radical pairs depends on their alignment in the magnetic field, it can provide information on magnetic directions. Cryptochromes, blue light-absorbing flavoproteins, with flavin adenine dinucleotide as chromophore, are suggested as molecules forming the radical pairs underlying magnetoreception. When activated by light, cryptochromes undergo a redox cycle, in the course of which radical pairs are generated during photo-reduction as well as during light-independent re-oxidation. This raised the question as to which radical pair is crucial for mediating magnetic directions. Here, we present the results from behavioural experiments with intermittent light and magnetic field pulses that clearly show that magnetoreception is possible in the dark interval, pointing to the radical pair formed during flavin re-oxidation. This differs from the mechanism considered for cryptochrome signalling the presence of light and rules out most current models of an avian magnetic compass based on the radical pair generated during photo-reduction. Using the radical pair formed during re-oxidation may represent a specific adaptation of the avian magnetic compass.

scholarly journals Very weak oscillating magnetic field disrupts the magnetic compass of songbird migrants

2017 ◽  
Vol 14 (133) ◽  
pp. 20170364 ◽  
Author(s):  
Alexander Pakhomov ◽  
Julia Bojarinova ◽  
Roman Cherbunin ◽  
Raisa Chetverikova ◽  
Philipp S. Grigoryev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Narrow Band ◽  
Radical Pair ◽  
Magnetic Compass ◽  
Sensitivity Threshold ◽  
Erithacus Rubecula ◽  
Long Distance ◽  
Pair Model ◽  
Oscillating Magnetic Field ◽  
Sylvia Borin

Previously, it has been shown that long-distance migrants, garden warblers ( Sylvia borin ), were disoriented in the presence of narrow-band oscillating magnetic field (1.403 MHz OMF, 190 nT) during autumn migration. This agrees with the data of previous experiments with European robins ( Erithacus rubecula ). In this study, we report the results of experiments with garden warblers tested under a 1.403 MHz OMF with various amplitudes (∼0.4, 1, ∼2.4, 7 and 20 nT). We found that the ability of garden warblers to orient in round arenas using the magnetic compass could be disrupted by a very weak oscillating field, such as an approximate 2.4, 7 and 20 nT OMF, but not by an OMF with an approximate 0.4 nT amplitude. The results of the present study indicate that the sensitivity threshold of the magnetic compass to the OMF lies around 2–3 nT, while in experiments with European robins the birds were disoriented in a 15 nT OMF but could choose the appropriate migratory direction when a 5 nT OMF was added to the stationary magnetic field. The radical-pair model, one of the mainstream theories of avian magnetoreception, cannot explain the sensitivity to such a low-intensity OMF, and therefore, it needs further refinement.

Inversion in the magnetic field effect of benzilketyl:SDS radical pair at high fields

1999 ◽  
Vol 305 (1-2) ◽  
pp. 63-70 ◽  
Author(s):  
Ajay Misra ◽  
Mintu Haldar ◽  
Mihir Chowdhury
Keyword(s):  
Magnetic Field ◽  
Field Effect ◽  
Radical Pair ◽  
Magnetic Field Effect ◽  
High Fields ◽  
The Magnetic Field

Dependence of the yield of a radical-pair reaction in the solid state on orientation in a magnetic field

1982 ◽  
Vol 104 (9) ◽  
pp. 2674-2675 ◽  
Author(s):  
Steven G. Boxer ◽  
Christopher E. D. Chidsey ◽  
Mark G. Roelofs
Keyword(s):  
Magnetic Field ◽  
Solid State ◽  
Radical Pair

scholarly journals Exploration of the close chemical space of tryptophan and tyrosine reveals importance of hydrophobicity in CW-photo-CIDNP performances

2021 ◽  
Vol 2 (1) ◽  
pp. 321-329
Author(s):  
Felix Torres ◽  
Alois Renn ◽  
Roland Riek
Keyword(s):  
Magnetic Field ◽  
Nuclear Polarization ◽  
Continuous Wave ◽  
Radical Pair ◽  
Chemical Space ◽  
Spin Dynamics ◽  
Basic Mechanism ◽  
Chemical Library ◽  
Chemically Induced ◽  
Small Chemical

Abstract. Sensitivity being one of the main hurdles of nuclear magnetic resonance (NMR) can be gained by polarization techniques including chemically induced dynamic nuclear polarization (CIDNP). Kaptein demonstrated that the basic mechanism of the CIDNP arises from spin sorting based on coherent electron–electron nuclear spin dynamics during the formation and the recombination of a radical pair in a magnetic field. In photo-CIDNP of interest here the radical pair is between a dye and the molecule to be polarized. Here, we explore continuous-wave (CW) photo-CIDNP (denoted CW-photo-CIDNP) with a set of 10 tryptophan and tyrosine analogues, many of them newly identified to be photo-CIDNP active, and we observe not only signal enhancement of 2 orders of magnitude for 1H at 600 MHz (corresponding to 10 000 times in measurement time) but also reveal that polarization enhancement correlates with the hydrophobicity of the molecules. Furthermore, the small chemical library established indicates the existence of many photo-CIDNP-active molecules.

scholarly journals On the low magnetic field effect in radical pair reactions

2018 ◽  
Vol 149 (3) ◽  
pp. 034103 ◽  
Author(s):  
Alan M. Lewis ◽  
Thomas P. Fay ◽  
David E. Manolopoulos ◽  
Christian Kerpal ◽  
Sabine Richert ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Effect ◽  
Radical Pair ◽  
Magnetic Field Effect ◽  
Low Magnetic Field
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