CRYSTAL-STRUCTURE OF DESHEXAPEPTIDE (B25-30) INSULIN AT 0.15 NM RESOLUTION

The crystal structure of deshexapeptide (B25-30) insulin has been refi ned to a resolution of 0.15 nm, using atomic coordinates of DH I struc ture determined at 0.25 nm resolution, through the use of the differen ce Fourier method and restrained least-squares method interspersed wit h careful review of the electron density map. After refinement, 54 wat er molecules with different occupancy factors were included in the fin al model!. The final crystallographic reliability R-factor is 0.187 in the 1.0-0.15 nm range of resolution. The root-mean-square deviations from the ideal bond lengths and bond angles are 0.001 6 nm and 2.7 deg rees respectively. The conformation and function of DH I and other ins ulin analogues have been discussed.