The ‘n’ effect in molecular recognition

Abstract

The cooperativity which exists in crystal melting and many biological molecular recognition phenomena arises from extended arrays of weak interactions. We present a correlation between the melting temperature of a crystal and the intermolecular energy (which is evident only when compounds possessing several or many internal rotors are excluded). The correlation is used as the basis for a model of crystal melting which is capable of estimating the melting temperature of crystals. This model provides the basis for an understanding of the sharpness of the crystal melting transition for organic and inorganic substances. The cooperativity illustrated by the extended arrays of weak interactions, or the "n' effect, is extended to analogous order/disorder transitions in biological systems, such as the "melting' of DNA and RNA duplexes, providing insights into the physical properties of these structures.

Peptide models of protein β-sheets: design, folding and insights into stabilising weak interactions

“…The peptide is largely unfolded in solution but shows a time-dependent tendency to aggregate, ultimately forming amyloid-like fibrils. 83 Thus, the conclusion from this study is that the size of the array of weakly interacting β-strands has a significant impact on the overall stability of the sheet, 84 and that model systems of limited size, involving a limited set of weak interactions, and lacking tertiary contacts, are unlikely to deliver a single low energy folded conformation that shows the characteristics of these extended β-sheet structures.…”

X-ray Diffraction and Molecular Simulation Study of the Crystalline and Liquid States of Succinic Anhydride

“…The molecular mechanism of melting of organic crystals has seldom been studied, and apparently has never been explained (see refs. [9,10], and discussions therein). This is even more true for the reverse process of crystal nucleation.…”

Study of mechanisms of chiral discrimination of amino acids and their derivatives on a teicoplanin-based chiral stationary phase

“…Additionally, they can favor (or hinder) specific orientations of the molecules in the pocket through weak hydrophobic interactions with the aglycone walls. The ligand in the binding site will have a different degree of motion that may improve (or decrease) the strength of existing interactions with different effects on the α value [44,45]. According to the k values reported in Table 1, it is evident that the tert group has a negative role in the stabilization of the molecule-CSP complex, causing a Pro represents an exception to the amino acids previously considered.…”