The binding of boronated peptides to low affinity mammalian saccharides.
Biopolymers 2018:e23101. [PMID:
29381187 DOI:
10.1002/bip.23101]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 11/09/2022]
Abstract
A 54-member library of boronated octapeptides, with all but the boronated residue being proteinogenic, was tested for affinity to a set of saccharides commonly found on the terminus of mammalian glycans. After experimentation with a high-throughput dye-displacement assay, attention was focused on isothermal titration calorimetry as a tool to provide reliable affinity data, including enthalpy and entropy of binding. A small number of boronated peptides showed higher affinity and significant selectivity for N-acetylneuraminic acid over methyl-α-d-galactopyranoside, methyl-α/β-l-fucopyranoside and N-acetyl-d-glucosamine. Thermodynamic data showed that for most of the boronated peptides studied, saccharide binding was associated with a significant increase in entropy, presumably resulting from the displacement of semiordered water molecules from around the sugar and/or peptide.
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