Mouse Nudt13 is a Mitochondrial Nudix Hydrolase with NAD(P)H Pyrophosphohydrolase Activity



Abdelraheim, Salama R, Spiller, David G and McLennan, Alexander G ORCID: 0000-0002-8057-2222
(2017) Mouse Nudt13 is a Mitochondrial Nudix Hydrolase with NAD(P)H Pyrophosphohydrolase Activity. PROTEIN JOURNAL, 36 (5). pp. 425-432.

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Abstract

The mammalian NUDT13 protein possesses a sequence motif characteristic of the NADH pyrophosphohydrolase subfamily of Nudix hydrolases. Due to the persistent insolubility of the recombinant product expressed in Escherichia coli, active mouse Nudt13 was expressed in insect cells from a baculovirus vector as a histidine-tagged recombinant protein. In vitro, it efficiently hydrolysed NADH to NMNH and AMP and NADPH to NMNH and 2',5'-ADP and had a marked preference for the reduced pyridine nucleotides. Much lower activity was obtained with other nucleotide substrates tested. K <sub>m</sub> and k <sub>cat</sub> values for NADH were 0.34 mM and 7 s<sup>-1</sup> respectively. Expression of Nudt13 as an N-terminal fusion to green fluorescent protein revealed that it was targeted exclusively to mitochondria by the N-terminal targeting peptide, suggesting that Nudt13 may act to regulate the concentration of mitochondrial reduced pyridine nucleotide cofactors and the NAD(P)<sup>+</sup>/NAD(P)H ratio in this organelle and elsewhere. Future studies of the enzymology of pyridine nucleotide metabolism in relation to energy homeostasis, redox control, free radical production and cellular integrity should consider the possible regulatory role of Nudt13.

Item Type: Article
Uncontrolled Keywords: Nudix, NADH, Mitochondria, Nucleotide metabolism, Pyrophosphatase
Depositing User: Symplectic Admin
Date Deposited: 23 Aug 2017 07:52
Last Modified: 19 Jan 2023 06:57
DOI: 10.1007/s10930-017-9734-x
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3009091