PMID: 7749917
Hua QX, Gozani SN, Chance RE, Hoffmann JA, Frank BH, Weiss MA
Structure of a protein in a kinetic trap.
Nat Struct Biol. 1995 Feb;2(2):129-38.
We have determined the structure of a metastable disulphide isomer of human insulin. Although not observed for proinsulin folding or insulin-chain recombination, the isomer retains ordered secondary structure and a compact hydrophobic core. Comparison with native insulin reveals a global rearrangement in the orientation of A- and B-chains. One face of the protein's surface is nevertheless in common between native and non-native structures. This face contains receptor-binding determinants, rationalizing the partial biological activity of the isomer. Structures of native and non-native disulphide isomers also define alternative three-dimensional templates. Threading of insulin-like sequences provide an experimental realization of the inverse protein-folding problem.