Increasing the affinity of an O-antigen polysaccharide binding site in Shigella flexneri bacteriophage Sf6 tailspike protein.

Increasing the affinity of an O-antigen polysaccharide binding site in Shigella flexneri bacteriophage Sf6 tailspike protein. Chemistry. 2020 Mar 19;: Authors: Kunstmann S, Engström O, Wehle M, Widmalm G, Santer M, Barbirz S Abstract Broad and unspecific use of antibiotics accelerates spread of resistances. Sensitive and robust pathogen detection is thus important for a more targeted application. Bacteriophages contain a large repertoire of pathogen-binding proteins. These tailspike proteins (TSP) often bind surface glycans and represent a promising design platform for specific pathogen sensors. We analyzed bacteriophage Sf6 TSP that recognizes the O-polysaccharide of dysentery-causing Shigella ( S. ) flexneri to develop variants with increased sensitivity for sensor applications. Ligand polyrhamnose backbone conformations were obtained from 2D 1 H, 1 H-trNOESY NMR utilizing methine-methine and methine-methyl correlations. They agreed well with conformations obtained from molecular dynamics (MD), validating the method for further predictions. In a set of mutants, MD predicted ligand flexibilities that were in good correlation with binding strength as confirmed on immobilized S. flexneri O-polysaccharide with surface plasmon resonance. In silico approaches combined with rapid screening on PS surfaces hence provide valuable strategies for TSP-based pathogen sensor design. PMID: 32189378 [PubMed - as supplied by publisher]
Source: Chemistry - Category: Chemistry Authors: Tags: Chemistry Source Type: research

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