Compositions and methods for treating hypophosphatasia

Abstract

The present invention provides compositions and methods for use in enzyme replacement therapy. The inventors disclose a method of producing membrane bound enzymes in an active soluble form by eliminating the glycosylphosphatidylinositol (GPI) membrane anchor. In particular the inventors disclose a soluble active form of the membrane bound enzyme TNSALP which they produced by deleting the GPI anchor single peptide sequence. They have further shown that this composition is useful for treatment of hypophosphatasia. The inventors also disclose oligo acid amino acid variants thereof which specifically target bone tissue.

1 . A composition comprising an active soluble ALP capable of treating ALP deficient disease.  
     
     
         2 . A composition as in  claim 1  wherein the active soluble ALP comprises an anchorless rhTNSALP comprising at least 88 percent homology with SEQ:1 residues 1-505.  
     
     
         3 . A composition as in  claim 2  wherein anchorless rhTNSALP further comprisinig 3 to 9 acidic amino acids providing increased affinity for hydroxyapatite.  
     
     
         4 . A composition as in  claim 3  whierein said acidic amino acids are selected from the group consisting of Aspartic acid and Glutanmic acid.  
     
     
         5 . A composition as in  claim 1  further conprising a cell maintained in conditions useful for expressing a nucleic acid sequence encoding an active soluble ALP.  
     
     
         6 . A composition as in  claim 5  wherein said nucleic acid encodes a protein with at least 88 percent homology to SEQ:1 residues 1-505.  
     
     
         7 . A composition as in  claim 5  wherein the cell is a CHO—K1 cell.  
     
     
         8 . A composition as in  claim 5  wherein said conditions are selected from the group of in vivo and in vitro.  
     
     
         9 - 21 . (canceled)