title: Crystal structure determination of desheptapeptide (B24--B30)-insulin.
abstract: Desheptapeptide (B24--B30)-insulin (DHPI), an essentially inactive insulin analog, is crystallized in space group P212121 with two molecules in an asymmetric unit. The orientations of the molecules in the crystal cell have been determined by using Patterson search method at 6 A resolution and the positions of the molecules are deduced from translation function calculation and R search at 3 A resolution. After using the rigid body refinement (CORELS) further to refine the orientational and positional parameters as well as the initial energy restrained refinement (EREF) for the model, the crystallographic R value is reduced to 0.384 at 3 A resolution. The initial Fourier map shows that the B-chain N-terminal (B1-B8) and C-terminal (B20-B22) segments, compared with the native 2 zinc insulin, exhibit drastic conformational changes, but the three helices of B- and A-chains and their relative arrangement are essentially kept in DHPI.
authors.affiliation: Institute of Biophysics, Academia Sinica, Beijing.
authors.forename: D C
authors.initials: DC
authors.lastname: Wang
authors.forename: G G
authors.initials: GG
authors.lastname: Lu
authors.forename: J P
authors.initials: JP
authors.lastname: Zhang
authors.forename: D L
authors.initials: DL
authors.lastname: Xie
authors.forename: W R
authors.initials: WR
authors.lastname: Chang
authors.forename: Z X
authors.initials: ZX
authors.lastname: Lu
authors.forename: D C
authors.initials: DC
authors.lastname: Liang
mesh_terms: D003461:Crystallography; D007328:Insulin / Q000031:analogs & derivatives* / Q000032:analysis; D010446:Peptide Fragments / Q000032:analysis*
chemical_list: D007328:Insulin; D010446:Peptide Fragments; C061055:insulin, des(heptapeptide)(B24-B30)-