Tweezers with Different Bite: Increasing the Affinity of Synthetic Receptors by Varying the Hinge Part

With preservation of selectivity, the hinge part of tweezerlike synthetic receptor molecules can be varied to achieve a higher affinity. The synthetic peptidosulfonamide receptor (below left; R=Disperse Red 1) with the bis(aminomethyl)benzoic acid hinge selectively bound the tripeptide shown below on the right (Ka=4100 M−1). Combination of a diversity in the hinge part with that present in the tweezer arms will provide access to large and diverse synthetic receptor libraries.