The signalling conformation of the insulin receptor ectodomain.

Nature communications (2018-10-26)
Felix Weis, John G Menting, Mai B Margetts, Shu Jin Chan, Yibin Xu, Norbert Tennagels, Paulus Wohlfart, Thomas Langer, Christoph W Müller, Matthias K Dreyer, Michael C Lawrence
ABSTRACT

Understanding the structural biology of the insulin receptor and how it signals is of key importance in the development of insulin analogs to treat diabetes. We report here a cryo-electron microscopy structure of a single insulin bound to a physiologically relevant, high-affinity version of the receptor ectodomain, the latter generated through attachment of C-terminal leucine zipper elements to overcome the conformational flexibility associated with ectodomain truncation. The resolution of the cryo-electron microscopy maps is 3.2 Å in the insulin-binding region and 4.2 Å in the membrane-proximal region. The structure reveals how the membrane proximal domains of the receptor come together to effect signalling and how insulin's negative cooperativity of binding likely arises. Our structure further provides insight into the high affinity of certain super-mitogenic insulins. Together, these findings provide a new platform for insulin analog investigation and design.

MATERIALS
Product Number
Brand
Product Description

SAFC
Insulin, Human Recombinant, dry powder, for research or for further manufacturing use
Sigma-Aldrich
Insulin from bovine pancreas, ≥25 USP units/mg (HPLC), powder