Fine-tuning the properties of the thrombin binding aptamer through cyclization: Effect of the 5′-3′ connecting linker on the aptamer stability and anticoagulant activity

A small library of cyclic TBA analogues (named cycTBA I-IV), obtained by covalently connecting its 5′- and 3′-ends with flexible linkers, has been synthesized with the aim of improving its chemical and enzymatic stability, as well as its anticoagulant properties. Two chemical procedures have been exploited to achieve the desired cyclization, based on the oxime ligation method (providing cycTBA I and II) or on Cu(I)-assisted azide-alkyne...