Crystallization and preliminary X-ray investigation of recombinant human interleukin 4

Crystals of recombinant human interleukin 4 have been grown from solutions of ammonium sulfate. The crystals are tetragonal, space-group P41212 or P43212; the unit cell axes are a = 92.2(1) Å and c = 46.4(1) Å. The crystals are stable to X-rays for at least three days and diffract beyond 2.8 Å resolution. The crystals contain approximately 63% solvent, assuming there is one molecule in the asymmetric unit.