Effect of deglycosylation of salivary glycoproteins on oral malodour production.
Putrefaction of saliva is commonly used as an in-vitro assay in oral malodour investigations.


OBJECTIVE
To exam the hypothesis that deglycosylation of salivary glycoproteins promotes oral malodour production.


METHODS
Porphyromonas gingivalis-mediated putrefaction of salivary glycoproteins was tested following preincubation of saliva in the presence of beta-galactosidase with or without glycosidic inhibitor (galactosamine), and in the presence of glucose with or without a non-glycosylated protein (bovine serum albumin).


METHODS
Malodour was determined by two odour judges, and volatile sulphides by using a sulphide monitor. Salivary glycoprotein degradation was measured densitometrically following electrophoresis on SDS-PAGE.


RESULTS
The addition of beta-galactosidase promoted salivary glycoprotein degradation and concomitant malodour production, whereas addition of a glycosidic inhibitor (D-galactosamine) inhibited this process. Glucose inhibited salivary glycoproteins putrefaction, but this inhibitory effect was mitigated when a non-glycosylated protein (BSA) was added.


CONCLUSIONS
Deglycosylation of salivary glycoproteins may be an initial step in oral malodour production. This process exposes the protein core of the glycoprotein, which is then further degraded by Gram-negative microorganisms under anaerobic conditions.
Sterer
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N
The Maurice and Gabriela Goldschleger School of Dental Medicine and Human Microbiology, Sackler Faculty of Medicine, Tel-Aviv University, Israel.
Rosenberg
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M
D003720:Densitometry; D004591:Electrophoresis, Polyacrylamide Gel; D005688:Galactosamine / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism*; D006209:Halitosis / Q000209:etiology* / Q000378:metabolism; D006801:Humans; D006862:Hydrogen Sulfide / Q000032:analysis; D016966:Porphyromonas gingivalis / Q000378:metabolism; D012463:Saliva / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013457:Sulfur Compounds / Q000032:analysis; D001616:beta-Galactosidase / Q000037:antagonists & inhibitors / Q000378:metabolism
D006023:Glycoproteins; D012471:Salivary Proteins and Peptides; D013457:Sulfur Compounds; D012710:Serum Albumin, Bovine; D005688:Galactosamine; D001616:beta-Galactosidase; D005947:Glucose; D006862:Hydrogen Sulfide