Protein-Glycan Quinary Interactions in Crowding Environment Unveiled by NMR Spectroscopy.
Related Articles Protein-Glycan Quinary Interactions in Crowding Environment Unveiled by NMR Spectroscopy.
Chemistry. 2017 Jun 25;:
Authors: Diniz A, S Dias J, Jiménez-Barbero J, Marcelo F, Cabrita EJ
Abstract
Protein-glycan interactions as modulators for quinary structure in crowding environments were explored. The interaction between human galectin 3 (Gal-3) and distinct macromolecular crowders, such as bovine and human serum albumin (BSA and HSA), Ficoll 70 and PEG3350, was scrutinized. The molecular recognition event of the specific ligand, lactose, by Gal-3 in crowding conditions was evaluated. Gal-3 interactions were monitored by NMR analysing chemical shift perturbation (CSP) and line broadening of 1H15N-HSQC signals. The intensity of the Gal-3 1H15N-HSQC signals decreased in the presence of all crowders, due to the increase in the solution viscosity and to the formation of large protein complexes. When glycosylated forms of BSA and HSA were used, signal broadening was more severe than that observed in the presence of the more viscous solutions of PEG3350 and Ficoll 70. However, for the samples containing glycosylated albumins, the signal intensity of 1H15N-HSQC recovered upon addition of lactose. We show that albumins interact with Gal-3, through their ?2,3-linked sialylgalactose moieties exposed at their surfaces, competing with lactose for the same binding site. The quinary interaction between Gal-3 and serum albumins, could help to co-localize Gal-3 at the cell surface, and may play a role in adhesion and signalling functions of this protein.
PMID: 28649731 [PubMed - as supplied by publisher]
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