The selection of a hydrophobic 7-phenylbutyl-7-deazaadenine-modified DNA aptamer with high binding affinity for the Heat Shock Protein 70

Abstract

Abstract Hydrophobic 7-phenylbutyl-7-deaadenine-modified DNA aptamers were selected against the Heat Shock Protein 70 via PEX and magnetic bead-based SELEX. After 9 rounds of selection, the pool was sequenced and a number of candidates were identified. Following initial screening, two modified aptamers were chemically synthesised in-house and their binding affinity analysed by two methods, bio-layer interferometry and fluorescent-plate-based binding assay. The binding affinities of the modified aptam,ers were compared with that of their natural counterparts. The resulting modified aptamers bound with higher affinity (low nanomolar range) to the Hsp70 than their natural sequence (> 5 µM) and hence have potential for applications and further development towards Hsp70 diagnostics or even therapeutics.