Structure and dynamics of micelle-bound human alpha-synuclein

J Biol Chem. 2005 Mar 11;280(10):9595-603. doi: 10.1074/jbc.M411805200. Epub 2004 Dec 22.

Abstract

Misfolding of the protein alpha-synuclein (aS), which associates with presynaptic vesicles, has been implicated in the molecular chain of events leading to Parkinson's disease. Here, the structure and dynamics of micelle-bound aS are reported. Val3-Val37 and Lys45-Thr92 form curved alpha-helices, connected by a well ordered, extended linker in an unexpected anti-parallel arrangement, followed by another short extended region (Gly93-Lys97), overlapping the recently identified chaperone-mediated autophagy recognition motif and a highly mobile tail (Asp98-Ala140). Helix curvature is significantly less than predicted based on the native micelle shape, indicating a deformation of the micelle by aS. Structural and dynamic parameters show a reduced helical content for Ala30-Val37. A dynamic variation in interhelical distance on the microsecond timescale is complemented by enhanced sub-nanosecond timescale dynamics, particularly in the remarkably glycine-rich segments of the helices. These unusually rich dynamics may serve to mitigate the effect of aS binding on membrane fluidity. The well ordered conformation of the helix-helix connector indicates a defined interaction with lipidic surfaces, suggesting that, when bound to larger diameter synaptic vesicles, it can act as a switch between this structure and a previously proposed uninterrupted helix.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Detergents
  • Humans
  • Magnetic Resonance Spectroscopy
  • Micelles*
  • Models, Molecular
  • Molecular Sequence Data
  • Nerve Tissue Proteins / chemistry*
  • Phosphoproteins / chemistry
  • Protein Structure, Secondary
  • Sodium Dodecyl Sulfate
  • Synucleins
  • alpha-Synuclein

Substances

  • Detergents
  • Micelles
  • Nerve Tissue Proteins
  • Phosphoproteins
  • SNCA protein, human
  • Synucleins
  • alpha-Synuclein
  • Sodium Dodecyl Sulfate

Associated data

  • PDB/1XQ8