Studies on the crystal structure of [L-Met]B0 bovine insulin at 3.0A resolution.

Based on the crystal symmetry of [L-Met]B0 bovine insulin (LMBBI) and the fundamental theory of the molecular packing method, the scheme for the determination of the position and orientation of the molecules by only using one-dimensional rotation and one-dimensional translation was chosen to be used, and therefore the calculation of the rotation function of the molecular replacement method and the refinement of the rotational and translational parameters by using the R-factor search method were simplified greatly. After the preliminary refinement by using the macromolecular rigid body refinement technique, the molecular model was further refined and adjusted by using the energy-minimizing stereochemical-restrained least squares refinement technique assisted by the manual revision on the difference Fourier maps. The L-Met residues on the N-terminus of the B-chain appeared clearly on the final electron density map.