NI2+ AND ZN2+-BINDING DNA MOTIFS REVEALED IN DNA APTAMERS TO AFRICAN SWINE FEVER VIRUS

Abstract

Rapid and accurate diagnosis of viral and bacterial infections is a significant challenge in medicine and veterinary science, especially in the case of epidemically dangerous pathogens. The African swine fever virus (ASFV) causes annual outbreaks among livestock, causing in significant economic losses for farmers. Artificial recognition elements, DNA aptamers, have been identified as a suitable tool for point-of-care diagnostics due to their high affinity and specificity for the target, as well as stability at ambient temperatures during storage. This study reports for the first time on DNA aptamers that can bind ASFV particles. The aptamers were generated using a single-round selection process; they bound to both recombinant p54 protein and ASFV particles as well as exhibited antiviral properties. Functional activity of one of the aptamers depended on Ni2+, which was a dopant during the selection process; this cation increased aptamer affinity by 100-fold. A combination of techniques was used to predict the structure of Ni2+-regulated aptamer identifying a new non-canonical DNA motif. Cation-dependent regulation of aptamer activity is promising as it allows regeneration of affine carriers and biosensors with chelating agents, while addition of Ni2+ restores the high-affine aptamer conformation.