Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.1.53 (
sialidase
)
2,694
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Factor IX and factor X have sialic acid in O-linked and N-linked oligosaccharides on their activation peptides, and a terminal sialic acid is found on a recently described O-linked tetrasaccharide at Ser-61 in the light chain of human factor IXa. In studies presented here, the potential role of sialic acid residues in mediating activity of human coagulation factors IX and X was tested after enzymatic removal of sialic acid residues. In contrast to previous reports, treatment of
factor IX
or factor IXa with recombinant
sialidase
did not decrease the rate of
factor IX
activation or proteolytic properties of human factor IXa. The activation rates of
factor IX
and desialated
factor IX
were indistinguishable when treated with factor XIa, with factor VIIa/tissue factor complex, and with the factor X activating enzyme from Russell's viper venom. Desialated human factor IXa showed full activity in the non-activated partial thromboplastin time assay and retained full "tenase" activity in a coupled amidolytic assay. Similar experiments with human factor X showed no detectable loss of clotting activity in the prothrombin time assay after desialation. Additionally, desialated human factor X was cleaved by the factor X activating enzyme from Russell's viper venom and intrinsic tenase at the same rate as untreated factor X when analyzed by SDS-polyacrylamide gel electrophoresis. These studies have shown that
factor IX
and factor X clotting activity are not dependent on sialic acid content. Further studies are needed to determine whether desialated
factor IX
binds to endothelial cells, and whether factors IX and X are more rapidly cleared from circulation or have altered susceptibility to proteolysis after enzymatic removal of sialic acid.
...
PMID:Enzymatic removal of sialic acid from human factor IX and factor X has no effect on their coagulant activity. 789 89
