Interaction with the heparin-derived binding inhibitors destabilizes galectin-3 protein structure

Sindrewicz, Paulina, Yates, Edwin A ORCID: 0000-0001-9365-5433, Turnbull, Jeremy E ORCID: 0000-0002-1791-754X, Lian, Lu-Yun and Yu, Lu-Gang ORCID: 0000-0001-9641-3712 (2020) Interaction with the heparin-derived binding inhibitors destabilizes galectin-3 protein structure. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 523 (2). pp. 336-341.

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Official URL: http://dx.doi.org/10.1016/j.bbrc.2019.12.054

Abstract

The β-galactoside-binding protein, galectin-3, is extensively involved in cancer development, progression and metastasis through multiple mechanisms. Inhibition of the galectin-3-mediated actions is increasingly considered as a promising therapeutic approach for cancer treatment. Our early studies have identified several novel galectin-3 binding inhibitors from chemical modification of the anticoagulant drug heparin. These heparin-derived galectin-3 binding inhibitors, which show no anticoagulant activity and bind to the galectin-3 canonical carbohydrate-binding site, induce galectin-3 conformational changes and inhibit galectin-3-mediated cancer cell adhesion, invasion and angiogenesis in vitro and reduce metastasis in mice. In this study, we determined the binding affinities of these heparin-derived ligands to galectin-3 using an isothermal titration calorimetry (ITC) ligand displacement approach. Such ITC experiments showed that the 2-de-O-sulphated, N-acetylated (compound E) and 6-de-O-sulphated, N-acetylated (F) heparin-derived ligands and their ultra-low molecular weight sub-fractions (E3 and F3) bind to galectin-3 with K<sub>D</sub> ranging from 0.96 to 1.32 mM.Differential scanning fluorimetry analysis revealed that, in contrast to the disaccharide ligand, N-acetyl-lactosamine, which binds to the fully folded form of galectin-3 and promotes galectin-3 thermal stability, the heparin-derived ligands preferentially bind to the unfolded state of galectin-3 and cause destabilization of the galectin-3 protein structure. These results provide molecular insights into the interaction of galectin-3 with the heparin-derived ligands and explain the previously demonstrated in vitro and in vivo effects of these binding inhibitors on galectin-3-mediated cancer cell behaviours.

Item Type:	Article
Uncontrolled Keywords:	Galectin-3, Heparin derivatives, Differential scanning fluorimetry, Isothermal titration calorimetry
Depositing User:	Symplectic Admin
Date Deposited:	15 Jan 2020 15:34
Last Modified:	19 Jan 2023 00:09
DOI:	10.1016/j.bbrc.2019.12.054
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3070677