2. Academic Validation
  3. Human MTH1 protein hydrolyzes the oxidized ribonucleotide, 2-hydroxy-ATP

Human MTH1 protein hydrolyzes the oxidized ribonucleotide, 2-hydroxy-ATP

  • Nucleic Acids Res. 2001 Jan 15;29(2):449-54. doi: 10.1093/nar/29.2.449.
K Fujikawa 1,  H Kamiya,  H Yakushiji,  Y Nakabeppu,  H Kasai
Affiliations

Affiliation

  • 1 Department of Environmental Oncology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
PMID: 11139615 DOI: 10.1093/nar/29.2.449
Abstract

The human nucleotide pool sanitization Enzyme, MTH1, hydrolyzes 2-hydroxy-dATP and 8-hydroxy-dATP in addition to 8-hydroxy-dGTP. We report here that human MTH1 is highly specific for 2-hydroxy-ATP, among the cognate ribonucleoside triphosphates. The pyrophosphatase activities for 8-hydroxy-GTP, 2-hydroxy-ATP and 8-hydroxy-ATP were measured by high-performance liquid chromatography. The kinetic parameters thus obtained indicate that the catalytic efficiencies of MTH1 are in the order of 2-hydroxy-dATP > 2-hydroxy-ATP > 8-hydroxy-dGTP > 8-hydroxy-dATP >> dGTP > 8-hydroxy-GTP > 8-hydroxy-ATP. Notably, MTH1 had the highest affinity for 2-hydroxy-ATP among the known substrates. ATP is involved in energy metabolism and signal transduction, and is a precursor in RNA synthesis. We suggest that the 2-hydroxy-ATP hydrolyzing activity of MTH1 might prevent the perturbation of these ATP-related pathways by the oxidized ATP.

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