Patent ID: 8263353
Filing Date: 2012-09-11
Classification: A61P,C12N,C12Q

Abstract:
1. A method for identifying processed, secreted proprotein convertase subtilisin-kexin type 9 (“PCSK9”) to the exclusion of nonprocessed, secreted PCSK9 in cell supernatant, which comprises: (a) transforming cells with an expression construct comprising nucleic acid encoding PCSK9 wherein an epitope tag is inserted immediately subsequent to nucleic acid encoding residue Q in the stretch of amino acids FAQ, said stretch of amino acids corresponding to amino acid residues 150-152 in human PCSK9, amino acid residues 153-155 in murine PCSK9, or amino acid residues 149-151 in rat PCSK9; (b) introducing into the supernatant of said transforming cell an antibody or anti-epitope molecule capable of recognizing the epitope tag only when located at the extreme amino-terminus, said antibody or anti-epitope molecule carrying a selectable marker which can be detected; and (c) detecting bound antibody or anti-epitope molecule carrying said selectable marker, bound antibody or anti-epitope molecule indicating processed, secreted PCSK9.