Nitric oxide synthases from photosynthetic organisms improve growth and confer nitrosative stress tolerance in E. coli. Insights on the pterin cofactor.

Autor: Correa-Aragunde N; Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, CC1245, Mar del Plata, Argentina. Electronic address: mncorrea@mdp.edu.ar., Nejamkin A; Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, CC1245, Mar del Plata, Argentina., Del Castello F; Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, CC1245, Mar del Plata, Argentina., Foresi N; Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, CC1245, Mar del Plata, Argentina., Lamattina L; Instituto de Investigaciones Biológicas-CONICET, Universidad Nacional de Mar del Plata, CC1245, Mar del Plata, Argentina. Electronic address: lolama@mdp.edu.ar.
Jazyk: angličtina
Zdroj: Nitric oxide : biology and chemistry [Nitric Oxide] 2022 Feb 01; Vol. 119, pp. 41-49. Date of Electronic Publication: 2021 Dec 20.
DOI: 10.1016/j.niox.2021.12.005
Abstrakt: Nitric oxide synthase (NOS) catalyzes NO formation from the substrate l-arginine (Arg). Previously, NOS with distinct biochemical properties were characterized from two photosynthetic microorganisms, the unicellular algae Ostreococcus tauri (OtNOS) and the cyanobacteria Synechococcus PCC 7335 (SyNOS). In this work we studied the effect of recombinant OtNOS and SyNOS expressed under IPTG-induced promoter in E. coli, a bacterium that lacks NOS. Results show that OtNOS and SyNOS expression promote E. coli growth in a nutrient replete medium and allow to better metabolize Arg as N source. In LB medium, OtNOS induces the expression of the NO dioxygenase hmp in E. coli, in accordance with high NO levels visualized with the probe DAF-FM DA. In contrast, SyNOS expression does not induce hmp and show a slight increase of NO production compared to OtNOS. NOS expression reduces ROS production and increases viability of E. coli cultures growing in LB. A strong nitrosative stress provoked by the addition of 1 mM of the NO donors sodium nitroprusside (SNP) and nitrosoglutathione (GSNO) inhibits bacterial growth rate. Under these conditions, the expression of OtNOS or SyNOS counteracts NO donor toxicity restoring bacterial growth. Finally, using bioinformatic tools and ligand docking analyses, we postulate that tetrahydromonapterin (MH4), an endogenous pterin found in E. coli, could act as cofactor required for NOS catalytic activity. Our findings could be useful for the development of biotechnological applications using NOS expression to improve growth in NOS-lacking bacteria.
(Copyright © 2021 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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