Preparation and preliminary X-ray diffraction studies of a new crystal form of L-asparaginase from Escherichia coli

L-Asparaginase is an enzyme which hydrolyzes asparagine to produce aspartic acid and ammonia. It is an effective chemotherapeutic drug, especially in the treatment of acute lymphoblastic leukaemia in children. The enzyme from Escherichia coli was crystallized in a new crystal form with space group C 2,unit-cell parameters a = 76.3 (0), b = 134.6(2), c = 64.8.(7) Angstrom, b eta = 110.5(1)degrees and a dimer in the asymmetric unit. Synchrotron-radia tion diffraction data have been collected to 1.95 Angstrom resolution.