New multidisciplinary study by researchers from the Functional Glycobiology Lab and XTAL - Macromolecular Crystallography Lab at UCIBIO-NOVA further elucidates the molecular recognition of dietary-derived mixed-linkage glucan carbohydrates with a prebiotic potential by Bacteroides ovatus, a prominent symbiont of the human gut microbiome. The research work, published in the Microbiology Spectrum Journal, has been developed by Viviana Correia (first author), Filipa Trovão and Benedita Pinheiro, and coordinated by Angelina Palma, leader of the Functional Glycobiology Lab, and Ana Luísa Carvalho, researcher at the XTAL - Macromolecular Crystallography Lab.
The research article addresses the need to increase knowledge on carbohydrate recognition by commensal bacteria at molecular level. The derived information on these interactions is vital to understanding the complex crosstalk of the microbiome with the human host and its implications in human health and disease. In this context, the study contributes with an integrative strategy to further elucidate the molecular determinants underlying the unique binding specificity of BoSGBPMLG-A, a key protein expressed at the surface of the prominent gut commensal Bacteroides ovatus for utilization of mixed-linkage β1,3-1,4-glucans. The strategy combines the power of the carbohydrate microarray technology for high-throughput analysis of structurally diverse carbohydrates and assignment of fine specificity with the high-resolution structure determination of protein-carbohydrate complexes using X-ray Crystallography. The interactions that occur at the binding site of BoSGBPMLG-A were mapped at high resolution, providing evidence for the role of crucial water-mediated interactions for fine specificity and affinity towards mixed-linkage β1,3-1,4 glucans. These are a group of dietary carbohydrates with proven health benefits that promote a healthy microbiota and have potential as prebiotics.
The authors conclude that “understanding at the molecular level how commensal bacteria can differentially utilize dietary carbohydrates with potential prebiotic activities will shed light on possible ways to modulate the microbiome to promote human health”.
Article:
Mapping Molecular Recognition of β1,3-1,4-Glucans by a Surface Glycan-Binding Protein from the Human Gut Symbiont Bacteroides ovatus. Viviana G. Correia, Filipa Trovão, Benedita A. Pinheiro, Joana L. A. Brás, Lisete M. Silva, Cláudia Nunes, Manuel A. Coimbra , Yan Liu, Ten Feizi, Carlos M. G. A. Fontes, Barbara Mulloy, Wengang Chai, Ana Luísa Carvalho and Angelina S. Palma, Microbiology Spectrum
DOI: https://doi.org/10.1128/Spectrum.01826-21