NMR structure of human apolipoprotein C-II in the presence of sodium dodecyl sulfate

Biochemistry. 2001 May 8;40(18):5414-21. doi: 10.1021/bi002821m.

Abstract

The structure and protein-detergent interactions of apolipoprotein C-II (apoC-II) in the presence of SDS micelles have been investigated using circular dichroism and heteronuclear NMR techniques applied to (15)N-labeled protein. Micellar SDS, a commonly used mimetic of the lipoprotein surface, inhibits the aggregation of apoC-II and induces a stable structure containing approximately 60% alpha-helix as determined by circular dichroism. NMR reveals the first 12 residues of apoC-II to be structurally heterogeneous and largely disordered, with the rest of the protein forming a predominantly helical structure. Three regions of helical conformation, residues 16-36, 50-56, and 63-77, are well-defined by NMR-derived constraints, with the intervening regions showing more loosely defined helical conformation. The structure of apoC-II is compared to that determined for other apolipoproteins in a similar environment. Our results shed light on the lipid interactions of apoC-II and its mechanism of lipoprotein lipase activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Apolipoprotein C-II
  • Apolipoproteins C / chemistry*
  • Carrier Proteins / chemistry
  • Circular Dichroism
  • Computer Simulation
  • Crystallography, X-Ray
  • Humans
  • Micelles
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular / methods
  • Peptide Fragments / chemistry
  • Protein Folding
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Sodium Dodecyl Sulfate / chemistry*

Substances

  • Apolipoprotein C-II
  • Apolipoproteins C
  • Carrier Proteins
  • Micelles
  • Peptide Fragments
  • Sodium Dodecyl Sulfate

Associated data

  • PDB/1I5J