Nucleotide Recognition in Water by a Guanidinium‐Based Artificial Tweezer Receptor

Abstract

The water-soluble tweezer receptor 1 with two symmetric peptidic arms, which are connected by an aromatic scaffold and contain lysine, phenylalanine, and a guanidinium-based anion-binding site as headgroup, has been synthesized. UV/Vis-derived Job plots show that the receptor forms 1:1 complexes with nucleotides and phosphate in buffered water at neutral pH. Binding constants have been determined by fluorescence and UV/Vis spectroscopy. All nucleotides tested were bound very efficiently, even in pure water, with binding constants between 10(4) and 10(5) M(-1) . Interestingly, all mononucleotides were bound much stronger than phosphate by a factor of at least 5 to 10. Furthermore 1 favors the binding of adenosine monophosphate (AMP) over adenosine diphosphate (ADP) and adenosine triphosphate (ATP), which is unprecedented for artificial nucleotide receptors reported so far. According to NMR spectroscopy and molecular modeling studies, the efficient binding is a result of strong electrostatic contacts supported by π-π interactions with the nucleobase within the cavity-shaped receptor.

Anion Recognition in Water: Recent Advances from a Supramolecular and Macromolecular Perspective

“…For these reasons, such motifs continue to find use in receptors designed for oxoanion recognition in pH‐neutral solutions. Kuchelmeister and Schmuck recently reported a guanidinium‐based tweezers‐like receptor ( 3 ), which binds nucleotide anions in buffered water solution at a physiological pH value 16. Notably, the receptor binds monoanionic adenosine monophosphate (AMP; K≈ 10 4   m −1 ) with an unprecedented selectivity over trianionic adenosine triphosphate (ATP), which associates an order of magnitude more weakly 16.…”

Chromogenic and fluorogenic chemosensors and reagents for anions. A comprehensive review of the years 2010–2011

“…109) was able to bind phosphates and nucleotides in buffered water at pH 7. 148 Aqueous solution of 228 presented an absorption at 300 nm. The intensity of this band gradually reduced upon the addition of selected anions (AMP, ADP, ATP, cAMP, UMP, GMP, CMP, PO 4 3-and P 2 O 7 4-).…”

DNA Triplexes That Bind Several Cofactor Molecules

“…However, when as econd base pairing interaction is allowed to takep lace, by leaving ag ap as binding site in the center of at riple helix, dissociation constants for complexesw ithn ucleotidesr each the nanomolar range. [14][15][16][17][18][19] With such ac ombination of Watson-Crick and Hoogsteen base pairing (Figure 1b), nucleoside phosphates can be bound with affinitiesh igher than those found for non-DNA binding motifs, such as pyridinium tripods, [20] artificial tweezers, [21] scorpiandr eceptors, [22] or copperc omplexes. [23] Further,g ood binding selectivities can be achieved, [15] and intracellularl evels of purine nucleotides can be affected.…”