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

ABSTRACT: Nucleotide-pyrophosphatases/phosphodiesterases (NPP/PDE) are membrane or secreted Zn²⁺-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 cy

SUBMITTER: Romero A 

PROVIDER: S-EPMC11624235 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature