Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 May;594(10):1497-1505.
doi: 10.1002/1873-3468.13745. Epub 2020 Feb 17.

Histidine triad nucleotide-binding proteins HINT1 and HINT2 share similar substrate specificities and little affinity for the signaling dinucleotide Ap4A

Alexander Strom  1 , Cher Ling Tong  2 , Carston R Wagner  1
Affiliations
Free article

Histidine triad nucleotide-binding proteins HINT1 and HINT2 share similar substrate specificities and little affinity for the signaling dinucleotide Ap4A

Alexander Strom et al. FEBS Lett. 2020 May.
Free article

Abstract

Human histidine triad nucleotide-binding protein 2 (hHINT2) is an important player in human mitochondrial bioenergetics, but little is known about its catalytic capabilities or its nucleotide phosphoramidate prodrug (proTide)-activating activity akin to the cytosolic isozyme hHINT1. Here, a similar substrate specificity profile (kcat /Km ) for model phosphoramidate substrates was found for hHINT2 but with higher kcat and Km values when compared with hHINT1. A broader pH range for maximum catalytic activity was determined for hHINT2 (pK1 = 6.76 ± 0.16, pK2 = 8.41 ± 0.07). In addition, the known hHINT1-microphthalmia-inducing transcription factor-regulating molecule Ap4 A was found to have no detectable binding to HINT1 nor HINT2 by isothermal titration calorimetry. These results demonstrate that despite differences in their sequence and localization, HINT1 and HINT2 have similar nucleotide substrate specificities, which should be considered in future proTide design and in studies of their natural function.

Keywords: Ap4A; hHINT1; hHINT2; pH profile; phosphoramidate; proTide; substrate specificity.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

References

    1. Brenner C, Bieganowski P, Pace HC and Huebner K (1999) The histidine triad superfamily of nucleotide-binding proteins. J Cell Physiol 181, 179-187.
    1. Mootha VK, Bunkenborg J, Olsen JV, Hjerrild M, Wisniewski JR, Stahl E, Bolouri MS, Ray HN, Sihag S, Kamal M et al. (2003) Integrated analysis of protein composition, tissue diversity, and gene regulation in mouse mitochondria. Cell 115, 629-640.
    1. Zhou X, Chou TF, Aubol BE, Park CJ, Wolfenden R, Adams J and Wagner CR (2013) Kinetic mechanism of human histidine triad nucleotide binding protein 1. Biochemistry 52, 3588-3600.
    1. Chou TF, Baraniak J, Kaczmarek R, Zhou X, Cheng J, Ghosh B and Wagner CR (2007) Phosphoramidate pronucleotides: a comparison of the phosphoramidase substrate specificity of human and Escherichia coli histidine triad nucleotide binding proteins. Mol Pharm 4, 208-217.
    1. Cha A and Budovich A (2014) Sofosbuvir: a new oral once-daily agent for the treatment of hepatitis C virus infection. P T. 39, 345-352.

Publication types

LinkOut - more resources