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Record W1977644100 · doi:10.1074/jbc.m000373200

Reaction of Human Myoglobin and H2O2

2000· article· en· W1977644100 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueJournal of Biological Chemistry · 2000
Typearticle
Languageen
FieldBiochemistry, Genetics and Molecular Biology
TopicHemoglobin structure and function
Canadian institutionsUniversity of British Columbia
FundersMedical Research CouncilNatural Sciences and Engineering Research Council of CanadaMedical Research Council CanadaNational Heart Foundation of Australia
KeywordsMyoglobinChemistryBiochemistry

Abstract

fetched live from OpenAlex

The human myoglobin (Mb) sequence is similar to other mammalian Mb sequences, except for a unique cysteine at position 110. Reaction of wild-type recombinant human Mb, the C110A variant of human Mb, or horse heart Mb with H(2)O(2) (protein/H(2)O(2) = 1:1.2 mol/mol) resulted in formation of tryptophan peroxyl (Trp-OO( small middle dot)) and tyrosine phenoxyl radicals as detected by EPR spectroscopy at 77 K. For wild-type human Mb, a second radical (g approximately 2. 036) was detected after decay of Trp-OO( small middle dot) that was not observed for the C110A variant or horse heart Mb. When the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) was included in the reaction mixture at protein/DMPO ratios </=1:10 mol/mol, a DMPO adduct exhibiting broad absorptions was detected. Hyperfine couplings of this radical indicated a DMPO-thiyl radical. Incubation of wild-type human Mb with thiol-blocking reagents prior to reaction with peroxide inhibited DMPO adduct formation, whereas at protein/DMPO ratios >/=1:25 mol/mol, DMPO-tyrosyl radical adducts were detected. Mass spectrometry of wild-type human Mb following reaction with H(2)O(2) demonstrated the formation of a homodimer (mass of 34,107 +/- 5 atomic mass units) sensitive to reducing conditions. The human Mb C110A variant afforded no dimer under identical conditions. Together, these data indicate that reaction of wild-type human Mb and H(2)O(2) differs from the corresponding reaction of other myoglobin species by formation of thiyl radicals that lead to a homodimer through intermolecular disulfide bond formation.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.018
Threshold uncertainty score0.236

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.012
GPT teacher head0.248
Teacher spread0.236 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it