Rapid screening for specific glycosylation and pathogen interactions on a 78 species avian egg white glycoprotein microarray

Marta Utratna,Marian Kane,Jared Q Gerlach,Lokesh Joshi,Yuan C Lee,Michelle Kilcoyne,Heidi Annuk

doi:10.1038/s41598-017-06797-6

Marta Utratna, Marian Kane + Show 5 more

Open Access

https://doi.org/10.1038/s41598-017-06797-6

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Abstract

There is an urgent need for discovery of novel antimicrobials and carbohydrate-based anti-adhesive strategies are desirable as they may not promote resistance. Discovery of novel anti-adhesive molecules from natural product libraries will require the use of a high throughput screening platform. Avian egg white (EW) provides nutrition for the embryo and protects against infection, with glycosylation responsible for binding certain pathogens. In this study, a microarray platform of 78 species of avian EWs was developed and profiled for glycosylation using a lectin panel with a wide range of carbohydrate specificities. The dominating linkages of sialic acid in EWs were determined for the first time using the lectins MAA and SNA-I. EW glycosylation similarity among the different orders of birds did not strictly depend on phylogenetic relationship. The interactions of five strains of bacterial pathogens, including Escherichia coli, Staphylococcus aureus and Vibrio cholera, identified a number of EWs as potential anti-adhesives, with some as strain- or species-specific. Of the two bacterial toxins examined, shiga-like toxin 1 subunit B bound to ten EWs with similar glycosylation more intensely than pigeon EW. This study provides a unique platform for high throughput screening of natural products for specific glycosylation and pathogen interactions. This platform may provide a useful platform in the future for discovery of anti-adhesives targeted for strain and species specificity.

Highlights

With the rise of antimicrobial resistance in human pathogens and the serious consequences of untreatable infections for human healthcare, there is increased interest in sourcing novel antimicrobial molecules, especially those which do not promote resistance1, 2
The Gal-α-(1,4)-Gal terminal structure is found in egg white (EW) oligosaccharides of a few species of birds distributed in closely positioned branches of the phylogenetic tree including pigeon EW (PEW), in amphibians and in a sea turtle16–18
Oligosaccharide structures from a small number of purified EW glycoproteins have been previously analysed by mass spectrometric methods, the majority of which are N-linked oligosaccharides11, 12, 20–22, with a small number of O-linked structures elucidated from Chicken EW (CEW) ovomucin23, 24

Summary

Introduction

With the rise of antimicrobial resistance in human pathogens and the serious consequences of untreatable infections for human healthcare, there is increased interest in sourcing novel antimicrobial molecules, especially those which do not promote resistance1, 2. The presence of bi-, tri- and tetra-antennary complex N-linked oligosaccharides, terminating most often with type II N-acetyllactosamine (LacNAc; Gal-β-(1,4)-GlcNAc) which is often sialylated34, on OVM was suggested by binding of both Phaseolus vulgaris erythroagglutinin (PHA-E) and Phaseolus vulgaris leucoagglutinin (PHA-L), while OVA only interacted with PHA-E and OVT did not bind with either lectin (Table 1 and Fig. 2).

Results

Conclusion