Abstract
Glycerophosphodiester phosphodiesterases (GDPD) are enzymes which degrade various glycerophosphodiesters to produce glycerol-3-phosphate and the corresponding alcohol moiety. Apart from this, a very interesting finding is that this enzyme could be used in the degradation of toxic organophosphorus esters, which has resulted in much attention on the biochemical and application research of GDPDs. In the present study, a novel GDPD from Pyrococcus furiosus DSM 3638 (pfGDPD) was successfully expressed in Escherichia coli and biochemically characterized. This enzyme hydrolyzed bis(p-nitrophenyl) phosphate, one substrate analogue of organophosphorus diester, with an optimal reaction temperature 55 °C and pH 8.5. The activity of pfGDPD was strongly dependent on existing of bivalent cations. It was strongly stimulated by Mn2+ ions, next was Co2+ and Ni2+ ions. Further investigations were conducted on its substrate selectivity towards different phospholipids. The results indicated that except of glycerophosphorylcholine (GPC), this enzyme also possessed lysophospholipase D activity toward both sn1-lysophosphatidylcholine (1-LPC) and sn2-lysophosphatidylcholine (2-LPC). Higher activity was found for 1-LPC than 2-LPC; however, no hydrolytic activity was found for phosphatidylcholine (PC). Molecular docking based on the 3D-modeled structure of pfGDPD was conducted in order to provide a structural foundation for the substrate selectivity.
Highlights
Glycerophosphodiesterase phosphodiesterases (GDPDs; EC 3.1.4.46) are ubiquitous among prokaryotic and eukaryotic organisms
No potential transmembrane domains and signal peptide region was found by analysis of protein sequence, which indicated it is a cytoplasmic protein in the cell
A highly conserved sequence motif (HR(X)nEN (X)nEXD(X)nHD) comprising the active site residues was found in the pfGDPD enzyme, with histidine 17 and histidine 59 as the putative catalytic residues (Figure 1B). pfGDPD exhibited highly sequence identity with the GDPD from Thermococcus kodakarensis KOD1(PDB:4OEC) (77%)
Summary
Glycerophosphodiesterase phosphodiesterases (GDPDs; EC 3.1.4.46) are ubiquitous among prokaryotic and eukaryotic organisms. The primary function of these enzymes is the degradation of various glycerophosphodiesters to glycerol-3-phosphate (G3P) and corresponding alcohol moiety (e.g., choline, serine, ethanolamine, inositol). It is a key enzyme in the phospholipid metabolism pathway which maintains G3P concentrations, for phospholipid remodelling and synthesis [1]. GDPDs have been characterized from bacterial, yeast, plant and mammalian cells [2]. Seven mammalian homologs of bacterial GDPDs have been identified (GDE1-GDE7), six of which were membrane proteins [7]. The proposed roles for these mammalian GDPDs include osteoblast and neuron differentiation, skeletal muscle development, anandamine biosynthesis and osmolyte regulation [8,9,10,11,12]. Screening and characterization of novel GDPDs that have great potential in the bioremediation applications has caused much interest amongst scientists
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
