Amylose Dimerization in Solution Can Be Studied Using a Model System.

Autor: Nybro Dansholm C; Department of Chemistry, Technical University of Denmark, Kemitorvet Building 207, Kongens Lyngby, DK-2800, Denmark., Meier S; Department of Chemistry, Technical University of Denmark, Kemitorvet Building 207, Kongens Lyngby, DK-2800, Denmark., Beeren SR; Department of Chemistry, Technical University of Denmark, Kemitorvet Building 207, Kongens Lyngby, DK-2800, Denmark.
Jazyk: angličtina
Zdroj: Chembiochem : a European journal of chemical biology [Chembiochem] 2024 Mar 01; Vol. 25 (5), pp. e202300832. Date of Electronic Publication: 2024 Feb 08.
DOI: 10.1002/cbic.202300832
Abstrakt: Amylose, the linear polymer of α-1,4-linked glucopyranose units, is known to crystallize as a parallel double helix, but evidence of this duplex forming in solution has remained elusive for decades. We show how the dimerization of short amylose chains can be detected in solution using NMR spectroscopy when the glucans are labeled at the reducing-end with an aromatic moiety that overcomes chemical shift degeneracy leading to distinct signals for the single-stranded and duplex amylose. A set of α-1,4 glucans with varying lengths of 6, 12, 18, and 22 glucose units and a 4-aminobenzamide label were synthesized, enabling the first systematic thermodynamic study of the association of amylose in solution. The dimerization is enthalpically driven, entropically unfavorable and beyond a minimum length of 12, each additional pair of glucose residues stabilizes the duplex by 0.85 kJ mol -1 . This fundamental knowledge provides a basis for a quantitative understanding of starch structure, gelation and enzymatic digestion, and lays the foundations for the strategic use of α-1,4-glucans in the development of self-assembled materials.
(© 2024 The Authors. ChemBioChem published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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