Insights into the structure and dynamics of lysyl oxidase propeptide, a flexible protein with numerous partners

Sci Rep. 2018 Aug 6;8(1):11768. doi: 10.1038/s41598-018-30190-6.

Abstract

Lysyl oxidase (LOX) catalyzes the oxidative deamination of lysine and hydroxylysine residues in collagens and elastin, which is the first step of the cross-linking of these extracellular matrix proteins. It is secreted as a proenzyme activated by bone morphogenetic protein-1, which releases the LOX catalytic domain and its bioactive N-terminal propeptide. We characterized the recombinant human propeptide by circular dichroism, dynamic light scattering, and small-angle X-ray scattering (SAXS), and showed that it is elongated, monomeric, disordered and flexible (Dmax: 11.7 nm, Rg: 3.7 nm). We generated 3D models of the propeptide by coarse-grained molecular dynamics simulations restrained by SAXS data, which were used for docking experiments. Furthermore, we have identified 17 new binding partners of the propeptide by label-free assays. They include four glycosaminoglycans (hyaluronan, chondroitin, dermatan and heparan sulfate), collagen I, cross-linking and proteolytic enzymes (lysyl oxidase-like 2, transglutaminase-2, matrix metalloproteinase-2), a proteoglycan (fibromodulin), one growth factor (Epidermal Growth Factor, EGF), and one membrane protein (tumor endothelial marker-8). This suggests new roles for the propeptide in EGF signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Dynamic Light Scattering
  • Glycosaminoglycans / metabolism
  • Humans
  • Molecular Dynamics Simulation
  • Protein-Lysine 6-Oxidase / chemistry*
  • Protein-Lysine 6-Oxidase / metabolism
  • Signal Transduction
  • X-Ray Diffraction

Substances

  • Glycosaminoglycans
  • Protein-Lysine 6-Oxidase