Patent ID: 7129335

Claim:
A method for isolating a recombinant chondroitinase, comprising: lysing a cell culture containing a recombinant chondroitinase having a terminal histidine tag, and passing the recombinant chondroitinase over a charged Ni 2+ column to isolate the recombinant chondroitinase, wherein the recombinant chondroitinase is a modified chondroitinase B having an amino acid sequence of the mature peptide of SEQ ID NO: 2 or conservative substitutions thereof, wherein at least one residue at a position selected from the group consisting of 116, 184, 213, 219, 245, 250, 271, 272, 296, 298, 318, 333, 363 and 364 of SEQ ID NO: 2 has been substituted or deleted.