1IZB

ROLE OF B13 GLU IN INSULIN ASSEMBLY: THE HEXAMER STRUCTURE OF RECOMBINANT MUTANT (B13 GLU-> GLN) INSULIN

1IZB の概要

• エントリーDOI: 10.2210/pdb1izb/pdb
• 分子名称: INSULIN, ZINC ION, ... (4 entities in total)
• 機能のキーワード: hormone
• 由来する生物種: Sus scrofa (pig); 詳細
• 細胞内の位置: Secreted: P01315 P01315
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 11764.15

構造登録者

Xiao, B.,Dodson, G.G. (登録日: 1992-10-16, 公開日: 1993-10-31, 最終更新日: 2024-10-30)

主引用文献

Bentley, G.A.,Brange, J.,Derewenda, Z.,Dodson, E.J.,Dodson, G.G.,Markussen, J.,Wilkinson, A.J.,Wollmer, A.,Xiao, B.
Role of B13 Glu in insulin assembly. The hexamer structure of recombinant mutant (B13 Glu-->Gln) insulin.
J.Mol.Biol., 228:1163-1176, 1992

PubMed Abstract: The assembly of the insulin hexamer brings the six B13 glutamate side-chains at the centre into close proximity. Their mutual repulsion is unfavourable and zinc co-ordination to B10 histidine is necessary to stabilize the well known zinc-containing hexamers. Since B13 is always a carboxylic acid in all known sequences of hexamer forming insulins, it is likely to be important in the hormone's biology. The mutation of B13 Glu-->Gln leads to a stable zinc-free hexamer with somewhat reduced potency. The structures of the zinc-free B13 Gln hexamer and the 2Zn B13 insulin hexamer have been determined by X-ray analysis and refined with 2.5 A and 2.0 A diffraction data, respectively. Comparisons show that in 2Zn B13 Gln insulin, the hexamer structure (T6) is very like that of the native hormone. On the other hand, the zinc-free hexamer assumes a quaternary structure (T3/R3) seen in the native 4Zn insulin hexamer, and normally associated only with high chloride ion concentrations in the medium. The crystal structures show the B13 Gln side-chains only contact water in contrast to the B13 glutamate in 2Zn insulin. The solvation of the B13 Gln may be associated with this residue favouring helix at B1 to B8. The low potency of the B13 Gln insulin also suggests the residue influences the hormone's conformation.

PubMed: 1361949
DOI: 10.1016/0022-2836(92)90323-C

実験手法

X-RAY DIFFRACTION (2 Å)