# The radiolysis of glyceraldehyde-3-phosphate dehydrogenase.
> グリセルアルデヒド-3-リン酸デヒドロゲナーゼの放射線分解における活性部位およびスルフヒドリル基の損失


## Abstract

This study quantified the radiation-induced loss of active sites and sulphydryl groups from glyceraldehyde-3-phosphate dehydrogenase, expressed as molecules per 100 eV, across nitrous-oxide-saturated, aerated, and argon-saturated aqueous solutions. Molecular hydrogen peroxide generated a sulphenic acid derivative that could be restored by post-irradiation dithiothreitol treatment. Under aerated conditions, both hydroxyl radicals (.OH) and superoxide radicals (.O2-) inactivated the enzyme at approximately 26% efficiency. In oxygen-free solutions, .OH efficiency was reduced, and inactivation attributable to hydrogen radicals (.H) or hydrated electrons (eaq-) was not substantial. A clear correlation was observed between sulphydryl group loss and active-site inactivation, suggesting that SH oxidation is a primary mechanism of enzyme damage.

### Mechanism

Hydroxyl and superoxide radicals generated by radiolysis oxidize sulphydryl groups at or near the enzyme active site, forming sulphenic acid intermediates and causing loss of catalytic activity.

## Bibliographic

- **Authors**: Buchanan JD, Armstrong DA
- **Journal**: Int J Radiat Biol Relat Stud Phys Chem Med
- **Year**: 1978
- **PMID**: [207651](https://pubmed.ncbi.nlm.nih.gov/207651/)
- **DOI**: [10.1080/09553007814550331](https://doi.org/10.1080/09553007814550331)
- **Study type**: in vitro study
- **Delivery route**: in vitro
- **Effect reported**: not assessed

## Delivery context

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 207651. https://h2-papers.org/en/papers/207651
> **Source**: PubMed PMID [207651](https://pubmed.ncbi.nlm.nih.gov/207651/)