COVALENT BINDING OF DEXTRAN TO THE ANTI‐LEUKEMIC ENZYME L‐ASPARAGINASE REDUCES THE ENZYME ANTIGEN REACTIVITY

Erwinia carotovora asparaginase was covalentlybound to activated soluble dextrans of molecular weight 10,000 (T10) and 70,000 (T70) daltons, as described previously (Elliott et a1 1981). Sepharose 4B gel filtration showed the resulting conjugates to be homogenous products of molecular weight 300,000 and 1.4 x 10 daltons respectively. The relative avidity of the conjugates was determined by cornprison with the native enzyme using quantitative immunoprecipitation against asparaginase specific antiserum raised in rabbits. The total enzyme activities remaining following incubation were also determined.