Simulations and Experiments Delineate Amyloid Fibrilization by Peptides Derived from Glaucoma-Associated Myocilin

J Phys Chem B. 2018 Jun 7;122(22):5845-5850. doi: 10.1021/acs.jpcb.8b03000. Epub 2018 May 21.

Abstract

Mutant myocilin aggregation is associated with inherited open angle glaucoma, a prevalent optic neuropathy leading to blindness. Comprehension of mutant myocilin aggregation is of fundamental importance to glaucoma pathogenesis and ties glaucoma to amyloid diseases such as Alzheimer's. Here, we probe the aggregation properties of peptides derived from the myocilin olfactomedin domain. Peptides P1 (residues 326-337) and P3 (residues 426-442) were identified previously to form amyloids. Coarse-grained discontinuous molecular dynamics simulations using the PRIME20 force field (DMD/PRIME20) predict that P1 and P3 are aggregation-prone; P1 consistently forms fibrillar aggregates with parallel in-register β-sheets, whereas P3 forms β-sheet-containing aggregates without distinct order. Natural abundance 13C solid-state NMR spectra validate that aggregated P1 exhibits amyloid signatures and is more homogeneous than aggregated P3. DMD/PRIME20 simulations provide a viable method to predict peptide aggregation propensities and aggregate structure/order which cannot be accessed by bioinformatics or readily attained experimentally.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Amyloid / metabolism*
  • Cytoskeletal Proteins / chemistry
  • Cytoskeletal Proteins / metabolism*
  • Eye Proteins / chemistry
  • Eye Proteins / metabolism*
  • Glaucoma, Open-Angle / metabolism
  • Glaucoma, Open-Angle / pathology
  • Glycoproteins / chemistry
  • Glycoproteins / metabolism*
  • Humans
  • Molecular Dynamics Simulation*
  • Nuclear Magnetic Resonance, Biomolecular
  • Peptides / chemistry
  • Peptides / metabolism*
  • Protein Aggregates / physiology
  • Protein Conformation, beta-Strand

Substances

  • Amyloid
  • Cytoskeletal Proteins
  • Eye Proteins
  • Glycoproteins
  • Peptides
  • Protein Aggregates
  • trabecular meshwork-induced glucocorticoid response protein