Nitric Oxide Inhibition Assay and the Respective Target Identification of an Aptamer Designed to Control...

Aptamers are emerging newer therapeutics and diagnostics whichcan be designed to bind any kind of target proteins. Vascular endothelial damage by the excess amount of nitric oxide production in systemic circulation leads to the secretion of inflammatory chemoattractants and cell adhesions are the prime pro-atherogenic events in the formation of plagues at atrial intimal layers due to oxidation - sensitive mechanisms. Nitric oxide inhibition assay is one of the valuable qualitative anti-atherosclerosis matrices.

In this research, Nitric oxide inhibition efficiency of an ssDNA aptamer on cell lines was studied, and the respective targets of that aptamer were identified by network analysis. The aptamer used here was originally designed for Selectin P Ligand Protein to control the atherogenic process. 20 nM of aptamer solution in Lipofectamine^TM 2000 sshowshighest level 70.5% inhibition of nitric oxide liberation on 24 hours cultured medium of lipopolysaccharide stimulated murine macrophage RAW 264.7 cell lines.

Protein interaction network analysis of the nitric oxide synthesis pathway interactors and the molecular docking analysis with network resulted in proteins such as AKT serine/threonine kinase 1, calmodulin, estrogen receptor 1, and nitric oxide synthase-3, which confirmed that the G - quadruplex Model of 18-mer sequence effectively bound to the active sites of estrogen receptor 1, and nitric oxide synthase-3.

The aptamer designed for atherosclerotic target has also exertedsignificant nitric oxide inhibition to control the atherogenic events through the proteins such as, AKT1, NOS3 and ESR1.