The growth of single crystals of (L-arginine)B0 bovine insulin and their preliminary X-ray crystallographic analysis.

The crystals of (L-Arg)B0 bovine insulin large enough for X-ray structure analysis have been grown by vapour diffusion in a buffer containing citrate, acetone and zinc chloride. The X-ray diffraction of the crystals extends to 3.0 A spacing. The crystals belong to the trigonal system with unit cell dimension of a = b = 81.82 A, c = 35.05 A, alpha = beta = 90 degrees, gamma = 120 degrees, space group R3. There are two insulin molecules in the crystallographic asymmetric unit.