Patent ID: 9651553
Date: 2017-05-16
CPC Classifications: C07K,C12N,C12Q,C12Y,G01N

Claim:
1. A method of detecting the activity of retargeted endopeptidase in a sample, wherein the retargeted endopeptidase comprises an enzymatic domain, the method comprising (a) contacting a cell with a sample suspected of comprising a retargeted endopeptidase, wherein the cell is from an established cell line expressing a SNAP-25 polypeptide consisting essentially of at least a portion of human SNAP-25 comprising SEQ ID NO:5 cleavage by the enzymatic domain, and wherein the established cell line is susceptible to intoxication by the retargeted endopeptidase at about or less than 50 nmol per liter culture medium, as indicated by the enzymatic cleavage of the SNAP-25 polypeptide by the enzymatic domain to yield a fragment of said SNAP-25 polypeptide comprising the amino acid sequence of SEQ ID NO:38; (b) isolating polypeptides from the cell; (c) contacting the polypeptides with an antibody selected from the group consisting of 1D3B8 having a heavy chain variable region comprising amino acid sequence of SEQ ID NO: 72 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 84, 2E2A6 having a heavy chain variable region comprising amino acid sequence SEQ ID NO: 76 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 88, 3C1A5 having a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 78 and a light chain variable region comprising the amino acid sequence SEQ ID NO: 90, and 3C3E2 having a heavy chain variable region comprising amino acid sequence of SEQ ID NO: 80 or SEQ ID NO: 82 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 92; and (d) detecting the presence of the antibody-polypeptide complex, wherein a higher amount of the antibody-polypeptide complex detected correlates to a higher amount of activity of the retargeted endopeptidase in the sample.