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Characterization of a sialate-O-acetylesterase (NanS) from the oral pathogen Tannerella forsythia that enhances sialic acid release by NanH, its cognate sialidase
- Source :
- The Biochemical journal. 472(2)
- Publication Year :
- 2015
-
Abstract
- Tannerella forsythia, a Gram-negative member of the Bacteroidetes has evolved to harvest and utilize sialic acid. The most common sialic acid in humans is a mono-N-acetylated version termed Neu5Ac (5-N-acetyl-neuraminic acid). Many bacteria are known to access sialic acid using sialidase enzymes. However, in humans a high proportion of sialic acid contains a second acetyl group attached via an O-group, i.e. chiefly O-acetylated Neu5,9Ac2 or Neu5,4Ac2. This diacetylated sialic acid is not cleaved efficiently by many sialidases and in order to access diacetylated sialic acid, some organisms produce sialate-O-acetylesterases that catalyse the removal of the second acetyl group. In the present study, we performed bioinformatic and biochemical characterization of a putative sialate-O-acetylesterase from T. forsythia (NanS), which contains two putative SGNH-hydrolase domains related to sialate-O-acetylesterases from a range of organisms. Purification of recombinant NanS revealed an esterase that has activity against Neu5,9Ac2 and its glycolyl form Neu5Gc,9Ac. Importantly, the enzyme did not remove acetyl groups positioned at the 4-O position (Neu5,4Ac2). In addition NanS can act upon complex N-glycans released from a glycoprotein [erythropoietin (EPO)], bovine submaxillary mucin and oral epithelial cell-bound glycans. When incubated with its cognate sialidase, NanS increased sialic acid release from mucin and oral epithelial cell surfaces, implying that this esterase improves sialic acid harvesting for this pathogen and potentially other members of the oral microbiome. In summary, we have characterized a novel sialate-O-acetylesterase that contributes to the sialobiology of this important human pathogen and has potential applications in the analysis of sialic acid diacetylation of biologics in the pharmaceutical industry.
- Subjects :
- Glycan
Sialomucins
Sialoglycoproteins
Sialate O-acetylesterase
Neuraminidase
Sialidase
Biochemistry
Microbiology
Substrate Specificity
chemistry.chemical_compound
Bacterial Proteins
Polysaccharides
Catalytic Domain
Cell Line, Tumor
Neuraminic acid
Tannerella forsythia
Animals
Bacteroides
Humans
Molecular Biology
Erythropoietin
biology
Sequence Homology, Amino Acid
Hydrolysis
Mouth Mucosa
Acetylation
Cell Biology
Hydrogen-Ion Concentration
biology.organism_classification
Recombinant Proteins
Sialic acid
chemistry
biology.protein
Sialic Acids
Acetylesterase
Cattle
Neuraminic Acids
Subjects
Details
- ISSN :
- 14708728
- Volume :
- 472
- Issue :
- 2
- Database :
- OpenAIRE
- Journal :
- The Biochemical journal
- Accession number :
- edsair.doi.dedup.....c9ce95de9298f48639f9367711488038