[Crystallization of free aspartate aminotransferase from chicken heart cytosol].

Homogeneous aspartate aminotransferase (purity--99%, yield--70%) has been prepared from chicken heart cytosol. The purification procedure included fractionation with ammonium sulfate and ethanol and crystallization. Crystals (0.3 x 0.5 x 2 mm) of the free enzyme were prepared from ammonium sulfate solution and studied by X-ray analysis at 2.5 A resolution.