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Updated: Jun 20, 2026
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Nucleoside Triphosphates - From Synthesis to Biochemical Characterization
Published on: April 3, 2014
NUDT5 hydrolyzes oxidized deoxyribonucleoside diphosphates with broad substrate specificity.
Hiroyuki Kamiya1, Mika Hori, Takao Arimori
1Hokkaido University, Sapporo, Japan. hirokam@pharm.hokudai.ac.jp
DNA Repair
|August 25, 2009
Summary
The human NUDT5 protein removes damaged DNA building blocks, specifically various oxidized deoxyribonucleoside diphosphates. This action protects cells from the harmful effects of these oxidized nucleotides.
Area of Science:
- Biochemistry
- Molecular Biology
- DNA Repair Mechanisms
Background:
- Oxidative stress generates DNA damage, including oxidized deoxyribonucleotides.
- Accumulation of damaged nucleotides can lead to mutations and cellular toxicity.
- Enzymes involved in nucleotide metabolism play a crucial role in maintaining genomic integrity.
Purpose of the Study:
- To investigate the substrate specificity of the human NUDT5 protein.
- To determine if NUDT5 can hydrolyze various oxidized deoxyribonucleotides.
- To understand the role of NUDT5 in eliminating potentially toxic nucleotide species.
Main Methods:
- Incubation of NUDT5 protein with four different oxidized deoxyribonucleotides.
- Enzymatic assays to measure hydrolysis rates.
- Kinetic parameter analysis (e.g., kcat, Km) to quantify substrate preference.
Main Results:
- NUDT5 efficiently hydrolyzed 8-hydroxy-dGDP and 8-hydroxy-dADP.
- Other oxidized deoxyribonucleotides (2-hydroxy-dADP, 5-formyl-dUDP) were also hydrolyzed, albeit with varying efficiencies.
- 5-hydroxy-dCDP was not hydrolyzed by NUDT5.
- Hydrolysis activity was significantly weaker for the corresponding triphosphate forms.
Conclusions:
- Human NUDT5 possesses broad substrate specificity for oxidized deoxyribonucleoside diphosphates.
- NUDT5 plays a significant role in clearing damaged nucleotide pool components.
- This enzymatic activity contributes to preventing the toxic effects associated with oxidized deoxyribonucleotides.
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