Bare Histidine–Serine Models: Implication and Impact of Hydrogen Bonding on Nucleophilicity. Issue 34 (5th July 2013)

• Record Type: Journal Article
• Authors: Leclaire, Julien; Mazari, Messaoud; Zhang, Yuan; Bonduelle, Colin; Thillaye du Boullay, Olivier; Martin‐Vaca, Blanca; Bourissou, Didier; De Riggi, Innocenzo; Fortrie, Rémy; Fotiadu, Frédéric; Buono, Gérard
• Is Part Of: Chemistry. Volume 19:Issue 34(2013)
• Page Start: 11301
• Page End: 11309
• Publication Date: 2013-07-05
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201301275
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A new family of 2‐hydroxyalk(en/yn)ylimidazoles has been evaluated as serine–histidine bare dyad models for the ring‐opening reaction of <sc>L</sc>‐lacOCA, a cyclic <italic>O</italic>‐carboxyanhydride. These models were selected to unravel the implication of intramolecular hydrogen bonding and to substantiate its influence on the nucleophilicity of the alcohol moiety, as it is suspected to occur in enzyme active sites. Although designed to exclusively facilitate the preliminary step of proton transfer during the studied ring‐opening reaction, these minimalistic models depicted a measureable increase in reactivity relative to the isolated fragments. A couple of reliable experimental and theoretical methods have been developed to readily monitor the strength of the intramolecular hydrogen bond in dilute solution. Results show that the folded conformers are the most nucleophilic species because of the intramolecular hydrogen bond.</p> </abstract>