Oligopeptide-CB[8] complexation with switchable binding pathways. Issue 14 (20th March 2019)

• Record Type: Journal Article
• Authors: Wu, Guanglu; Clarke, David E.; Wu, Ce; Scherman, Oren A.
• Is Part Of: Organic & biomolecular chemistry. Volume 17:Issue 14(2019)
• Page Start: 3514
• Page End: 3520
• Publication Date: 2019-03-20
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c9ob00592g
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Two-stage binding of dipeptide with CB[8] leads to the unambiguous determination of n : n stoichiometric complexation. Abstract : Host–guest complexes exhibiting a 1 : 1 binding stoichiometry need not consist of a single host and guest. A series of oligopeptides, which were previously reported to have abnormally high binding enthalpies were investigated to deduce whether they exist as a 2 : 2 quaternary or a 1 : 1 binary complex with cucurbit[8]uril (CB[8]). Through a systematic study of the sequence-specific binding pathways of peptide-CB[8] association, a phenylalanine-leucine dipeptide was found to be capable of switching from a 1 : 1 stoichiometric complex to a 2 : 1 complex. By studying the differences in size-based diffusion properties of these two binding modes, the presence of a 1 : 1 pairwise inclusion complex was verified for the regime where CB[8] is in excess. Findings in this study can be utilised to 'customise' the precise CB[8]-oligopeptide self-assembly pathway, acting as a useful toolbox in the design of supramolecular systems.