A Comparative Analysis of Sialic Acid Binding Proteins for Better Understanding of their Role in Host Pathogen Interaction and Human Health: A Bioinformatics Perspective

Sialic acids, especially N-acetylneuraminic acid, serve as pivotal molecular interfaces between host tissues and invading pathogens by modulating attachment, immune evasion, and metabolic processes. In this study, we performed a comprehensive bioinformatics analysis of sialic acid binding proteins (SABPs) to unravel their structural diversity, evolutionary distribution, and functional roles across bacteria and viruses. A curated dataset of 209 SABPs was retrieved from the UniProt database, with inclusion criteria emphasizing annotated sialic acid binding activity and sequence completeness. Notably, 208 proteins in this collection are backed by experimentally determined 3D structures, enabling in-depth examination of their binding sites and catalytic domains. Gene Ontology (GO) analyses revealed that these proteins are predominantly involved in critical biological processes related to host-pathogen interaction, such as virion attachment to host cells, membrane fusion, and carbohydrate metabolism. Molecular function terms were dominated by host cell surface receptor binding, carbohydrate binding, and hydrolase activities targeting glycosyl bonds. Cellular component annotations highlighted membrane localization and extracellular secretions, consistent with roles in mediating initial host contact and pathogen dissemination. Taxonomic assessments showed a strong representation of Orthomyxoviridae, underlining the importance of hemagglutinin and neuraminidase in influenza viruses, while bacterial families such as Clostridiaceae and Staphylococcaceae contributed SABPs involved in sialic acid catabolism and toxin-mediated virulence. Family-level clustering pinpointed hemagglutinins, neuraminidases (glycosyl hydrolases GH33 and GH34), and immunoglobulin superfamily members—further emphasizing the widespread evolutionary adoption of sialic acid recognition. These findings collectively underscore the centrality of SABPs in host-pathogen interactions and offer a valuable resource for future research aimed at leveraging sialic acid biology for therapeutic and diagnostic advancements.