Pa2794 is a Pseudomonas aeruginosa PAO1 enzyme that exhibits pseudaminidase activity

Abstract

Pseudomonas aeruginosa (P. aeruginosa) is an important bacterial pathogen frequently reported in hospitalized patients, immunocompromised hosts and patients with cystic fibrosis. The main mechanisms of P. aeruginosa virulence and antibiotic resistance include secreted toxins and the attachment to surfaces by formation of biofilms. Bacterial neuraminidases are relevant for their implication in biofilm biogenesis during host infection. Pseudaminic acid (Pse) is a nonulosonic acid derivative found as a component of cell surface glycans (oligosaccharides and glycoproteins), essential for bacterial virulence and host’s immune response. However, because of the lack of synthetic access to structurally-defined pseudaminylated glycoconjugates, the biological significance of this special carbohydrate is still largely unknown. Previously, a P. aeruginosa PAO1 a “neuraminidase-like” enzyme (Pa2794) was characterized, and it was suggested by computer modelling that could accommodate Pse with high affinity. Mutants of the neuraminidase Pa2794 gene (null Δ2794) were found virulent, but unable to colonize the respiratory tract or produce biofilm. By using Pse metabolic labeling we studied the potential enzymatic activity of Pa2794 against Pse- containing glycoproteins and lipopolysaccharide (LPS) from several bacterial strains.