Glycosylation-mediated inhibition of Factor X

Abstract

Reagents that specifically bind a carbohydrate target wherein sialic acid is linked at the nonreducing terminus of a glycoside to a galactose or galactosamine residue through an α2-6 linkage are able to inhibit the conversion of human Factor X to human Factor Xa. These reagents (SA/Gal/GalNAc binding reagents) as well as other strategies for inhibiting the conversion of Factor X to Factor Xa are useful in treating thrombosis, inflammation and other conditions associated with excess thrombin activity.

1 . A method to inhibit the conversion of human Factor X to human Factor Xa, which method comprises contacting human Factor X with a reagent capable of specifically binding sialic acid residues that are α2-6 linked to galactose or galactosamine residues (SA/Gal/GalNAc binding reagent) in an amount and for a time sufficient to complex to Factor X.  
     
     
         2 . The method of  claim 1  wherein said SA/Gal/GalNAc binding reagent is a lectin.  
     
     
         3 . The method of  claim 2  wherein said lectin is Sambucus nigra agglutinin (SNA).  
     
     
         4 . The method of  claim 1  wherein said SA/Gal/GalNAc binding reagent is an antibody.  
     
     
         5 . The method of  claim 1  wherein said SA/Gal/GalNAc binding reagent is a mammalian lectin.  
     
     
         6 . The method of  claim 1  wherein said SA/Gal/GalNAc binding reagent is a peptide derived from Factor IXa/VIIIa or tissue factor/Factor VIIa.  
     
     
         7 . A complex comprising an SA/Gal/GalNAc binding reagent and human Factor X.  
     
     
         8 . The complex of  claim 7  wherein said SA/Gal/GalNAc binding reagent is a lectin.  
     
     
         9 . The complex of  claim 8  wherein said lectin is Sambucus nigra agglutinin (SNA).  
     
     
         10 . The complex of  claim 7  wherein said SA/Gal/GalNAc binding reagent is an antibody.  
     
     
         11 . The complex of  claim 7  wherein said SA/Gal/GalNAc binding reagent is a mammalian lectin.  
     
     
         12 . The complex of  claim 7  wherein said SA/Gal/GalNAc binding reagent is a peptide derived from Factor IXa/VIIIa or tissue factor/Factor VIIa.  
     
     
         13 . A pharmaceutical composition useful in inhibiting the conversion of Factor X to Factor Xa, which composition comprises, as active ingredient, a SA/Gal/GalNAc binding reagent in admixture with a pharmaceutically acceptable excipient.  
     
     
         14 . The composition of  claim 13  wherein said SA/Gal/GalNAc binding reagent is a lectin.  
     
     
         15 . The composition of  claim 14  wherein said lectin is Sambucus nigra agglutinin (SNA).  
     
     
         16 . The composition of  claim 13  wherein said SA/Gal/GalNAc binding reagent is an antibody.  
     
     
         17 . The composition of  claim 13  wherein said SA/Gal/GalNAc binding reagent is a mammalian lectin.  
     
     
         18 . The composition of  claim 13  wherein said SA/Gal/GalNAc binding reagent is a peptide derived from Factor IXa/VIIIa or tissue factor/Factor VIIa.  
     
     
         19 . A method to prevent or treat thrombosis in a human subject, which method comprises administering to a subject in need of such treatment an effective amount of an SA/Gal/GalNAc binding reagent or pharmaceutical composition thereof.  
     
     
         20 . A method to prevent or treat inflammation in a human subject, which method comprises administering to a subject in need of such treatment an effective amount of an SA/Gal/GalNAc binding reagent or pharmaceutical composition thereof.  
     
     
         21 . A method to prevent or treat restenosis in a human subject, which method comprises administering to a subject in need of such treatment an effective amount of an SA/Gal/GalNAc binding reagent or pharmaceutical composition thereof.  
     
     
         22 . A method to prevent or treat complications of transplantation in a human subject, which method comprises administering to a subject in need of such treatment an effective amount of an SA/Gal/GalNAc binding reagent or pharmaceutical composition thereof.  
     
     
         23 . A method to inhibit the conversion of human Factor X to human Factor Xa which method comprises contacting human Factor X with a reagent capable of cleaving glycosylation moieties from said Factor X in an amount and for a time sufficient to cleave said glycosylation moieties.  
     
     
         24 . The method of  claim 23  wherein said glycosidase is a neuraminidase.  
     
     
         25 . A method to inhibit the conversion of human Factor X to human Factor Xa which method comprises contacting human Factor X with a reagent capable of binding to the glycosylation moieties of the activation peptide of Factor X in an amount and for a time sufficient to bind said peptide.  
     
     
         26 . A method to inhibit the conversion of human Factor X to human Factor Xa, which method comprises contacting human Factor X with at least one soluble analog of SA/Gal/GalNAc, said contacting being under conditions which would normally, in the absence of said soluble analog, effect the conversion of Factor X to Factor Xa.  
     
     
         27 . The method of  claim 26  wherein said conditions are those of the extrinsic or intrinsic pathway.  
     
     
         28 . The method of  claim 26  wherein said contacting is effected by administering said soluble analog to a living organism.  
     
     
         29 . A method to inhibit the conversion of human Factor X to human Factor Xa in a living organism, which method comprises administering to said organism an effective amount of an inhibitor of glycosylation.  
     
     
         30 . The method of  claim 29  wherein said inhibitor inhibits a sialyl transferase.