Millitesla magnetic field effects on the photocycle of an animal cryptochrome

2017 · Mixed · Low evidence

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MixedLow evidencePaper 2059

Study snapshot

Publicationmanual · 2017

Study typein_vitro

Reported directionMixed

Evidence ratingLow

Abstract

Millitesla magnetic field effects on the photocycle of an animal cryptochrome Sheppard DM, Li J, Henbest KB, Neil SR, Maeda K, Storey J, Schleicher E, Biskup T, Rodriguez R, Weber S, Hore PJ, Timmel CR, Mackenzie SR. Millitesla magnetic field effects on the photocycle of an animal cryptochrome. Sci Rep. 2017 Feb 8;7:42228. doi: 10.1038/srep42228. Abstract Drosophila have been used as model organisms to explore both the biophysical mechanisms of animal magnetoreception and the possibility that weak, low-frequency anthropogenic electromagnetic fields may have biological consequences. In both cases, the presumed receptor is cryptochrome, a protein thought to be responsible for magnetic compass sensing in migratory birds and a variety of magnetic behavioural responses in insects. Here, we demonstrate that photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome are indeed influenced by magnetic fields of a few millitesla. The form of the protein containing flavin and tryptophan radicals shows kinetics that differ markedly from those of closely related members of the cryptochrome-photolyase family. These differences and the magnetic sensitivity of Drosophila cryptochrome are interpreted in terms of the radical pair mechanism and a photocycle involving the recently discovered fourth tryptophan electron donor. Open access paper: ncbi.nlm.nih.gov

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typein_vitro

Effect directionmixed

PopulationNot supplied

Sample sizeNot supplied

ExposureNot supplied

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome were influenced by magnetic fields of a few millitesla. The flavin/tryptophan radical-containing form showed kinetics that differed markedly from closely related cryptochrome-photolyase family members, and the magnetic sensitivity was interpreted in terms of a radical pair mechanism and a photocycle involving a fourth tryptophan electron donor.

Outcomes measured

Photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome
Photocycle/kinetics of flavin and tryptophan radical-containing form of cryptochrome
Magnetic field sensitivity consistent with radical pair mechanism and involvement of a fourth tryptophan electron donor

Limitations

Frequency of the magnetic field exposure is not specified in the abstract.
Exposure duration and detailed dosimetry are not provided in the abstract.
Study context appears to be mechanistic/biophysical; implications for organism-level health outcomes are not assessed in the abstract.

View raw extracted JSON

{
  "study_type": "in_vitro",
  "exposure": {
    "band": null,
    "source": "laboratory magnetic field exposure",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome",
    "Photocycle/kinetics of flavin and tryptophan radical-containing form of cryptochrome",
    "Magnetic field sensitivity consistent with radical pair mechanism and involvement of a fourth tryptophan electron donor"
  ],
  "main_findings": "Photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome were influenced by magnetic fields of a few millitesla. The flavin/tryptophan radical-containing form showed kinetics that differed markedly from closely related cryptochrome-photolyase family members, and the magnetic sensitivity was interpreted in terms of a radical pair mechanism and a photocycle involving a fourth tryptophan electron donor.",
  "effect_direction": "mixed",
  "limitations": [
    "Frequency of the magnetic field exposure is not specified in the abstract.",
    "Exposure duration and detailed dosimetry are not provided in the abstract.",
    "Study context appears to be mechanistic/biophysical; implications for organism-level health outcomes are not assessed in the abstract."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "cryptochrome",
    "Drosophila melanogaster",
    "magnetic field",
    "millitesla",
    "photocycle",
    "electron transfer",
    "radical pair mechanism",
    "tryptophan radicals",
    "magnetoreception"
  ],
  "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1038/srep42228
PubMed: Not supplied

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