Crystallization and preliminary X-ray diffraction studies of cobra venom beta-nerve growth factor

beta-Nerve growth factor (beta-NGF) is a 118 amino acid residue polypeptide with an important role in the survival and development of certain neuronal populations. A beta-NGF purified from cobra venom was crystallized by the hanging-drop vapor diffusion method. The crystals belong to the tetragonal space group P4(1)2(1)2 (or its enantiomorph P4(3)2(1)2) with unit-cell parameters a=b=61.75, c=154.40A. X-ray data from these crystals were collected to 3.2A resolution. Analysis of the packing density shows that the asymmetric unit probably contains two molecules. The self-rotation calculation implied that a beta-NGF dimer might exist in the asymmetric unit.