PMID: 8760462
Authors:
Ding J, Wan Z, Chang W, Liang D
Title:
Molecular replacement study on form-B monoclinic crystal of insulin.
Journal:
Sci China C Life Sci. 1996 Apr;39(2):144-53.
Abstract:
The form-B monoclinic insulin crystal was obtained from the sodium citrate buffer with 1% zinc chloride, keeping phenolic content between 0.76% and 1.25%. Its space group is P2(1), cell constants are: a = 4.924 nm, b = 6.094 nm, c = 4.818 nm, beta = 95.8 degrees. There are 6 insulin molecules which form a hexamer. The initial phase was obtained by using rotation function program of X-PLOR program package and molecular packing program of our laboratory. The molecular model was chosen from 4 zinc bovine insulin hexamer. 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 stereochemically restrained least-squared refinement on the difference Fourier maps. The final R-factor is 22.4% at 0.3 nm resolution, the r.m.s. deviations from standard bond length and bond angle are 0.0022 nm and 4.7 degrees, respectively.