Increased Aggregation Tendency of Alpha-Synuclein in a Fully Disordered Protein Complex

J Mol Biol. 2019 Jun 28;431(14):2581-2598. doi: 10.1016/j.jmb.2019.04.031. Epub 2019 Apr 26.


The recent discovery of biologically active fully disordered, so called random fuzzy protein-protein interactions leads to the question of how the high flexibility of these protein complexes correlates to aggregation and pathologic misfolding. We identify the structural mechanism by which a random fuzzy protein complex composed of the intrinsically disordered proteins alpha-Synuclein and SERF1a is able to potentiate cytotoxic aggregation. A structural model derived from an integrated NMR/SAXS analysis of the reconstituted aSyn:SERF1a complex enabled us to observe the partial deprotection of one precise aSyn amyloid nucleation element in the fully unstructured ensemble. This minimal exposure was sufficient to increase the amyloidogenic tendency of SERF1a-bound aSyn. Our findings provide a structural explanation of the previously observed pro-amyloid activity of SERF1a. They further demonstrate that random fuzziness can trigger a structurally organized disease-associated reaction such as amyloid polymerization.

Keywords: Alpha synuclein; Amyloids; Fuzzy complexes; Intrinsically disordered proteins; MOAG-4/SERF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amyloid / chemistry*
  • Animals
  • Brain / cytology
  • Brain / metabolism*
  • Humans
  • Intrinsically Disordered Proteins / chemistry
  • Intrinsically Disordered Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Models, Molecular
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / metabolism*
  • Neuroblastoma / metabolism*
  • Neuroblastoma / pathology
  • Protein Binding
  • Protein Conformation
  • Protein Multimerization
  • Sequence Homology
  • alpha-Synuclein / chemistry*
  • alpha-Synuclein / metabolism*


  • Amyloid
  • Intrinsically Disordered Proteins
  • Nerve Tissue Proteins
  • SERF1A protein, human
  • alpha-Synuclein