Mechanical Tuning of Molecular Recognition To Discriminate the Single-Methyl-Group Difference between Thymine and Uracil

Abstract

Construction of enzyme-like artificial cavities is a complex and challenging subject. Rather than synthesizing complicated host molecules, we have proposed mechanical adaptation of relatively simple hosts within dynamic media to determine the optimum conformation for molecular recognition. Here we have applied this concept to one of the most challenging biomolecular recognition problems, i.e., that of discriminating thymine from uracil. We synthesized the novel cholesterol-armed triazacyclononane as a host molecule and subjected it to structural tuning by compression of its Langmuir monolayers in the absence and in the presence of Li(+) cations in the subphase. Experimental results confirm that the monolayer of triazacyclononane host selectively recognizes uracil over adenine (ca. 7 times based on the binding constant) and thymine (ca. 64 times) under optimized conditions ([LiCl] = 10 mM at surface pressure of 35 mN m(-1)). The concept of mechanical tuning of a host structure for optimization of molecular recognition offers a novel methodology in host-guest chemistry as an alternative to the more traditional molecular design strategies.

Interaction of O-acylated chitosans with biomembrane models: Probing the effects from hydrophobic interactions and hydrogen bonding

“…These changes in area were obtained from the difference between neat monolayers and monolayers spread on subphases containing 0.05 mg mL −1 derivatives at a fixed pressure of 30 mN m −1 . The larger expansion for DPPCT is consistent with the results by Mori et al [37], where an additional CH 3 group in thymine -compared to uracyl -yielded a larger expansion of cholesterol-armed triazacylclononane monolayers. Since area was larger for the zwitterionic DPPC for DPPCT subphases and the same as for DPPG and DMPA for DACT subphases, one infers that electrostatic interactions cannot be the dominant force.…”

Functional Nanomaterials Prepared by Nanoarchitectonics-Based Supramolecular Assembly

“…The molecular machine can catch and release guest molecules based on hand-motion-like microscopic motions. Similarly, control of molecular phenomena including chiral recognition [48,49], nucleic acid base discrimination [50], glucose detection by indicator displacement assay [51], and controllable drug delivery [52] by macroscopic mechanical motions have been demonstrated using interfacial media and related structures. These are realistic examples of accessing molecular-level functions from the macroscopic world.…”

Mechanochemical Tuning of the Binaphthyl Conformation at the Air–Water Interface

“…[20] Recently,w eh ave reported that molecular properties can be tuned by applying amechanical force to amonolayer at the air-water interface. [21][22][23] However,a lthough variation of properties should originate from changes at the molecular level, at that time these could be only inferred.…”