TY - JOUR
T1 - Effect of mucin and glucose on proteolytic and glycosidic activities of Streptococcus oralis
AU - Rafay, A. M.
AU - Homer, K. A.
AU - Beighton, D.
PY - 1996
Y1 - 1996
N2 - The production of glycosidase and protease activities, which may play a role in the degradation of human glycoproteins, by Streptococcus oralis strains isolated from endocarditis, septicaemia or the oral cavity was investigated with a range of fluorogenic substrates. The pH optima of the proteases ranged from 6.0 to 9.3 and the pH optima for the glycosidases were lower (4.5-6.0), although the pH range over which both groups of enzymes acted was broad. Growth in a minimal medium supplemented with glucose resulted in repression of glycosidase activities and elevated proteolytic activity. Bacteria from cultures supplemented with porcine gastric mucin (PGM), a model glycoprotein, exhibited higher levels of glycosidase activity, while proteolytic activity was suppressed and glycoprotein-derived monosaccharides were transported at significantly higher rates than those observed for cells grown in media with glucose. PGM-derived cells also exhibited high levels of N-acetylneuraminate pyruvate-lyase, the first intracellular enzyme in the pathway of sialic acid catabolism. Taken together, these data indicate that S. oralis strains produce a range of proteolytic and glycosidic enzymes that may play a role in the degradation of host-derived glycoproteins.
AB - The production of glycosidase and protease activities, which may play a role in the degradation of human glycoproteins, by Streptococcus oralis strains isolated from endocarditis, septicaemia or the oral cavity was investigated with a range of fluorogenic substrates. The pH optima of the proteases ranged from 6.0 to 9.3 and the pH optima for the glycosidases were lower (4.5-6.0), although the pH range over which both groups of enzymes acted was broad. Growth in a minimal medium supplemented with glucose resulted in repression of glycosidase activities and elevated proteolytic activity. Bacteria from cultures supplemented with porcine gastric mucin (PGM), a model glycoprotein, exhibited higher levels of glycosidase activity, while proteolytic activity was suppressed and glycoprotein-derived monosaccharides were transported at significantly higher rates than those observed for cells grown in media with glucose. PGM-derived cells also exhibited high levels of N-acetylneuraminate pyruvate-lyase, the first intracellular enzyme in the pathway of sialic acid catabolism. Taken together, these data indicate that S. oralis strains produce a range of proteolytic and glycosidic enzymes that may play a role in the degradation of host-derived glycoproteins.
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U2 - 10.1099/00222615-44-6-409
DO - 10.1099/00222615-44-6-409
M3 - Article
C2 - 8636957
AN - SCOPUS:0029893696
SN - 0022-2615
VL - 44
SP - 409
EP - 417
JO - Journal of Medical Microbiology
JF - Journal of Medical Microbiology
IS - 6
ER -