Free amino acids accelerate the time-dependent inactivation of rat liver nucleotide pyrophosphatase/phosphodiesterase Enpp3 elicited by EDTA.

Autor: Romero A; Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina y Ciencias de la Salud, Universidad de Extremadura, 06006, Badajoz, Spain., Cumplido-Laso G; Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, 06006, Badajoz, Spain., Fernández A; Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina y Ciencias de la Salud, Universidad de Extremadura, 06006, Badajoz, Spain., Moreno J; Colegio María Inmaculada Ríos Rosas, c/Ríos Rosas 35, 28003, Madrid, Spain., Canales J; Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina y Ciencias de la Salud, Universidad de Extremadura, 06006, Badajoz, Spain., Ferreira R; Departamento de Química e Bioquímica, Escola de Ciências e Tecnologia, Universidade de Évora, 7002-554, Evora, Portugal., López-Gómez J; Servicio de Análisis Clínicos, Hospital Universitario de Badajoz, Servicio Extremeño de Salud, 06006, Badajoz, Spain., Ribeiro JM; Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina y Ciencias de la Salud, Universidad de Extremadura, 06006, Badajoz, Spain. jribeiro@unex.es., Costas MJ; Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina y Ciencias de la Salud, Universidad de Extremadura, 06006, Badajoz, Spain., Cameselle JC; Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina y Ciencias de la Salud, Universidad de Extremadura, 06006, Badajoz, Spain.
Jazyk: angličtina
Zdroj: Amino acids [Amino Acids] 2024 Dec 06; Vol. 57 (1), pp. 1. Date of Electronic Publication: 2024 Dec 06.
DOI: 10.1007/s00726-024-03431-4
Abstrakt: Nucleotide-pyrophosphatases/phosphodiesterases (NPP/PDE) are membrane or secreted Zn 2+ -metallohydrolases of nucleoside-5´-monophosphate derivatives. They hydrolyze, for instance, ATP and 4-nitrophenyl-dTMP, and belong to the ecto-nucleotide pyrophosphatase/phosphodiesterase (ENPP) family that contains seven members (ENPP1-ENPP7). Earlier we had shown that an NPP/PDE activity solubilized and partially purified from rat liver membranes is inactivated by EDTA in a time-dependent fashion, an effect enhanced by glycine and blocked by the 4-nitrophenyl-dTMP. Here, we extended this observation to other free amino acids. Activity assays started after different incubation lengths with EDTA provided first-order, apparent inactivation constants (k i(ap) ). With the exception of cysteine (a strong inhibitor) and histidine (itself evoking a time-dependent inactivation), free amino acids themselves did not affect activity but increased k i(ap) . The results are compatible with a conformational change of NPP/PDE evoked by interaction with free amino acids. The enzyme preparation was analyzed to identify what ENPP family members were present. First, the hydrolytic activity on 2´,3´-cGAMP was assayed because until very recently ENPP1 was the only mammalian enzyme known to display it. 2´,3´-cGAMP hydrolase activity was clearly detected, but mass spectrometry data obtained by LC-MS/MS gave evidence that only rat Enpp3, Enpp4 and Enpp5 were present with low abundance. This finding coincided in time with a recent publication claiming that mouse Enpp3 hydrolyzes 2´,3´-cGAMP, and that Enpp1 and Enpp3 account for all the 2´,3´-cGAMP hydrolase activity in mice. So, our results are confirmatory of Enpp3 activity towards 2´,3´-cGAMP. Finally, the effect of amino acids could be relevant to NPP/PDE actions dependent on protein-protein interactions, like the known insulin-related effects of ENPP1 and possibly ENPP3.
Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests.
(© 2024. The Author(s).)
Databáze: MEDLINE
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