Conformational structure-dependent molecular recognition of two aptamers for tetracycline

Abstract

Different aptamers towards one target molecule can be selected by Systematic Evolution of Ligands by Exponential Enrichment (SELEX), however, not all aptamers have real world practicability. In this study, conformational structure-dependent molecular recognition of two aptamers towards tetracycline (TC), 76 mer and 40 mer, was studied both quantitatively and computationally. Two formats of competitive enzyme-linked aptamer assay (ELAA), a molecular docking module and Isothermal Titration Calorimeter (ITC) analysis were used to further investigate the two selected aptamers. With longer strand length, more G, C bases, and more recognition sites for TC, the 76 mer aptamer showed better performance than the 40 mer aptamer. Deciphering the relevance of aptamers with different molecular characteristics towards one target molecule can furnish as a referral guidance for aptamer selection and further practical application.