7NOZ

Structure of the nanobody stablized properdin bound alternative pathway proconvertase C3b:FB:FP

7NOZ の概要

• エントリーDOI: 10.2210/pdb7noz/pdb
• 分子名称: Complement C3 beta chain, alpha-D-mannopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (13 entities in total)
• 機能のキーワード: protease, complement, cascade, proconvertase, immune system
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 317060.38

構造登録者

Lorenzen, J.,Pedersen, D.V.,Andersen, G.R. (登録日: 2021-02-26, 公開日: 2022-07-27, 最終更新日: 2024-01-31)

主引用文献

Lorentzen, J.,Pedersen, D.V.,Gadeberg, T.A.F.,Andersen, G.R.
Structure determination of an unstable macromolecular complex enabled by nanobody-peptide bridging.
Protein Sci., 31:e4432-e4432, 2022

PubMed Abstract: Structure determination of macromolecular complexes is challenging if subunits can dissociate during crystallization or preparation of electron microscopy grids. We present an approach where a labile complex is stabilized by linking subunits though introduction of a peptide tag in one subunit that is recognized by a nanobody tethered to a second subunit. This allowed crystal structure determination at 3.9 Å resolution of the highly non-globular 320 kDa proconvertase formed by complement components C3b, factor B, and properdin. Whereas the binding mode of properdin to C3b is preserved, an internal rearrangement occurs in the zymogen factor B von Willebrand domain type A domain compared to the proconvertase not bound to properdin. The structure emphasizes the role of two noncanonical loops in thrombospondin repeats 5 and 6 of properdin in augmenting the activity of the C3 convertase. We suggest that linking of subunits through peptide specific tethered nanobodies represents a simple alternative to approaches like affinity maturation and chemical cross-linking for the stabilization of large macromolecular complexes. Besides applications for structural biology, nanobody bridging may become a new tool for biochemical analysis of unstable macromolecular complexes and in vitro selection of highly specific binders for such complexes.

PubMed: 36173177
DOI: 10.1002/pro.4432

実験手法

X-RAY DIFFRACTION (3.9 Å)