What does this research mean for the field?

Gut bacterial sialidases exhibit pronounced position-dependent preferences for O-acetylated sialic acid, with 4-O-acetylation completely preventing hydrolysis while 8/9-O-acetylation is broadly tolerated. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To determine the position-specific substrate preferences and catalytic tolerance of gut bacterial sialidases toward O-acetylated sialic acid modifications.

September 10, 2026GlycobiologyOpen Access

Defined O-acetylated Neu5Ac substrates reveal position-specific preferences of gut bacterial sialidases

View Full Paper

Ask AI

Bookmark

Authors

NPNikita PodvalnyyUniversity of Zurich LPLuca PlanUniversity of Zurich SGSereina GutUniversity of Zurich

Discussion

Member takes

Implication

Biochemical analysis reveals position-specific inhibition of gut bacterial sialidases by 4-O-acetylated sialic acid, highlighting a key mechanism regulating gut glycan degradation.

Key Points

To determine the position-specific substrate preferences and catalytic tolerance of gut bacterial sialidases toward O-acetylated sialic acid modifications.
Characterized six GH33 sialidases from Bacteroides spp. and Akkermansia muciniphila using chemically defined substrates bearing 4-O-, 7-O-, or 8/9-O-acetylated Neu5Ac.
Assayed endogenous murine caecal sialidase activity and tested enzymatic rescue with a viral sialate O-acetylesterase.
Assessed cell-surface glycan remodeling across primary murine colonic and splenic lymphocytes via lectin and Siglec-E-Fc binding.
Commensal GH33 sialidases and endogenous caecal sialidases cleaved 8/9-O-acetylated Neu5Ac and variably accommodated 7-O-acetylation, but completely failed to cleave 4-O-acetylated Neu5Ac.
Removal of the 4-O-acetyl group by a viral sialate O-acetylesterase restored cleavage, confirming that C4 acetylation directly obstructs catalytic hydrolysis.
Pathogen-derived NanI sialidase consistently reduced colon tissue lectin (SNA, MAL2) and Siglec-E-Fc binding, whereas commensal sialidases showed restricted, tissue-specific remodeling.

Cite This Study

Podvalnyy et al. (2026) studied this question.

synapsesocial.com/papers/6aa27b5758559d80afc7486e https://doi.org/10.1093/glycob/cwag078

View Full Paper

Ask AI

Bookmark

Implication

Biochemical analysis reveals position-specific inhibition of gut bacterial sialidases by 4-O-acetylated sialic acid, highlighting a key mechanism regulating gut glycan degradation.

Defined O-acetylated Neu5Ac substrates reveal position-specific preferences of gut bacterial sialidases

Discussion

Member takes

Implication

Key Points

Cite This Study

Defined O-acetylated Neu5Ac substrates reveal position-specific preferences of gut bacterial sialidases

Discussion

Member takes

Implication

Key Points

Cite This Study

Also Consider

Also Consider