Choudhary Amit, Fry Charles G, Raines Ronald T
ARKIVOC. 2010 Jul 8;2010:251-262.
Noncovalent interactions play an essential role in biological and chemical processes. In the main chain of common protein secondary structures, the lone pair (n) of a carbonyl oxygen is delocalized into the antibonding orbital (π*) of the subsequent carbonyl group. Herein, experimental and computational data reveal that this n→π* interaction can be attenuated by the inductive electron withdrawal of one or two α-fluoro groups in the donor. The steric effect of three α-fluoro groups, however, overcomes the inductive withdrawal. These data evoke a means to modulate the n→π* interaction in peptides, proteins, and other systems.
非共价相互作用在生物和化学过程中起着至关重要的作用。在常见蛋白质二级结构的主链中，羰基氧的孤对电子（n）离域到后续羰基的反键轨道（π*）中。在此，实验和计算数据表明，供体中一个或两个α-氟基团的诱导吸电子作用可减弱这种n→π相互作用。然而，三个α-氟基团的空间效应克服了诱导吸电子作用。这些数据引出了一种调节肽、蛋白质和其他体系中n→π相互作用的方法。
