(426f) Simulations and Experiments Delineate Amyloid Fibrilization By Peptides Derived from Glaucoma-Associated Myocilin

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 amyloid. 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 less heterogeneous than aggregated P3. DMD/PRIME20 simulations provide a viable method to predict peptide aggregation propensities and aggregate’s structure/order which cannot be accessed by bioinformatics or readily attained experimentally.