# Hydrogen Evolution of a Unique DNAzyme Composed of Cobalt-Protoporphyrin IX and G-Quadruplex DNA.
> コバルトプロトポルフィリンIXとGクアドラプレックスDNAからなる人工DNAザイムによる水素発生


## Abstract

An artificial DNAzyme was engineered by combining cobalt-protoporphyrin IX (CoPP) with G-quadruplex DNA, incorporating a distinctive H2O ligand positioned between the CoPP center and the G-quartet planes. Under anaerobic conditions at pH 6.05 and 10°C, this CoPP-DNAzyme catalyzed photo-induced H2 generation over 12 hours, achieving a turnover number (TON) of 1229 ± 51. Complexation with G-quadruplex DNA enhanced H2 production activity 4.7-fold relative to free CoPP. The TON exhibited a pH dependence with a pKa of 7.60 ± 0.05, attributed to the acid-base equilibrium between Co(III)-H2O and Co(I) states. These findings indicate that the H2O ligand plays a key role in modulating catalytic efficiency, and the system represents a promising platform for solar-driven water splitting to produce molecular hydrogen.

### Mechanism

Complexation of CoPP with G-quadruplex DNA enhances photocatalytic H2 production 4.7-fold by modulating the acid-base equilibrium between Co(III)-H2O and Co(I) states (pKa 7.60), with the H2O ligand serving as a key regulatory element.

## Bibliographic

- **Authors**: Cui Y, Zhang LL, Liu J, Zhang T, Sugahara A, Momotake A, et al.
- **Journal**: ChemSusChem
- **Year**: 2024 (2024-01-08)
- **PMID**: [37681481](https://pubmed.ncbi.nlm.nih.gov/37681481/)
- **DOI**: [10.1002/cssc.202301244](https://doi.org/10.1002/cssc.202301244)
- **Study type**: in vitro study
- **Delivery route**: in vitro
- **Effect reported**: positive

## 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 37681481. https://h2-papers.org/en/papers/37681481
> **Source**: PubMed PMID [37681481](https://pubmed.ncbi.nlm.nih.gov/37681481/)