Disclosed herein are polypeptides which exhibit asparaginase activity and little to no glutaminase activity. The polypeptides have sequences which correspond to W. succinogenes asparaginase, but have an amino acid residue other than proline at amino acid position 121. The polypeptides exhibit higher kinetic rates of asparaginase activity to glutaminase activity as compared to W. succinogenes asparaginase and Elspar®, an E. coli asparaginase.
