A novel platelet-activating factor acetylhydrolase discovered in a metagenome from the earthworm-associated microbial community

作者：Navarro Fernandez Jose; Nechitaylo Taras Y; Guerrero Jose A; Golyshina Olga V; Garcia Carmona Francisco; Sanchez Ferrer Alvaro^*; Golyshin Peter N

来源：Environmental Microbiology, 2011, 13(11): 3036-3046.

DOI：10.1111/j.1462-2920.2011.02581.x

Metagenomics is an emerging field for mining the bioresources for new biomolecules for potential application in biotechnology and biomedicine. In the present study, a novel acetylhydrolase (Est13) was detected during the function-based screening of a metagenomic library established from the DNA extracted from the cellulose-depleting microbial community set up with an earthworm cast. Analysis showed that Est13 exhibited some similarities with a human and parasite platelet-activating factor acetylhydrolase (PAF-AH) belonging to the SGNH hydrolase superfamily. Biochemical characterization of the purified recombinant enzyme using substrates common for hydrolases of this superfamily demonstrated that Est13 hydrolysed p-nitrophenyl acetate quite efficiently, with a kcat/KM value of 3209 mM-1 s-1. The Est13 showed highest activity at pH 8.0 and 40 degrees C, conditions in which it is relatively stable compared with known PAF-AHs. In vitro functional analysis of the platelet-activating factor hydrolysis showed a dose- and time-dependent inhibition of platelet aggregation in the range of 24 mu M, making this enzyme a potential candidate for biomedical applications.

• 出版日期2011-11