What they found
Original description of ionic self-complementary oligopeptides EAK16 and RADA16 (RAD16). A 16-residue peptide with alternating hydrophilic charged and hydrophobic alanine residues forms a characteristic beta-sheet CD spectrum in water; upon addition of millimolar monovalent salts (physiological conditions), spontaneously assembles into a stable macroscopic membrane. Membrane resists heat, extremes of pH, guanidinium HCl, SDS/urea, and proteolytic enzymes. Filament diameter by scanning EM: approximately 10–20 nm. No atomic-resolution structure — primary contribution is discovery and macroscopic characterization.
How this applies to h09
Establishes the RADA16 scaffold as the backbone for h09’s synthetic horizontal top connector. The 10–20 nm filament diameter (EM) is the original size estimate; later refined to 3–8 nm individual fibrils (Paravastu 2014 TEM) — the larger value likely reflects bundled fibers. The observation that the assembled membrane resists proteolytic enzymes is relevant to the K_PROTEOLYSIS assumption, though no kinetic quantification is given.
Key numbers
- Filament diameter (scanning EM): 10–20 nm
- Assembly trigger: millimolar monovalent salt (NaCl, KCl), physiological conditions
- Stability: resists protease, denaturants, heat, extreme pH after assembly
- Peptide: 16 residues, (RADA)4 or (EAKA)4 motif
Links
- PubMed: https://pubmed.ncbi.nlm.nih.gov/7682699/
- PMC: https://pmc.ncbi.nlm.nih.gov/articles/PMC46294/
- DOI: https://doi.org/10.1073/pnas.90.8.3334
Connections
- STRC Horizontal Top Connector Hydrogel Hypothesis — foundational scaffold paper; fibril dimensions
- STRC Phase 4d F-actin Bundling Model — supports proteolytic stability claim but provides no rate data
[see-also]2005-yokoi-kinoshita-zhang-rada16-reassembly — fibril geometry AFM follow-up[see-also]Paravastu 2014 — RADA16 molecular structure (TODO paper note) — atomic structure NMR follow-up