Structural differences between apoE3 and apoE4 may be useful in developing therapeutic agents for Alzheimer's disease

Proc Natl Acad Sci U S A. 2012 Jun 5;109(23):8913-8. doi: 10.1073/pnas.1207022109. Epub 2012 May 21.


Apolipoproteins E3 and E4, proteins with a molecular mass of 34.15 kDa, differ by a single amino acid change. ApoE4 contains an arginine residue at position 112, whereas apoE3 has a cysteine at this position. ApoE4 is the major risk factor for late-onset Alzheimer's disease, whereas apoE3, the common isoform, is neutral with respect to this disease. Here, using literature data from both hydrogen-deuterium exchange and site-directed mutations, we suggest structural differences between these two isoforms that are distant from the site of the arginine-to-cysteine change. These structural differences involve sequences from both the N- and C-terminal domains, sequentially far apart but structurally close. In addition, these regions are close to regions that bind lipid and to a region involved in association of apoE monomers to higher molecular weight forms. We discuss the possibility that these regions could be targeted preferentially to affect the function of apoE4 relative to apoE3.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Alzheimer Disease / drug therapy
  • Alzheimer Disease / genetics*
  • Alzheimer Disease / prevention & control
  • Apolipoprotein E3 / chemistry
  • Apolipoprotein E3 / genetics*
  • Apolipoprotein E4 / chemistry
  • Apolipoprotein E4 / genetics*
  • Deuterium Exchange Measurement
  • Drug Discovery
  • Humans
  • Models, Molecular*
  • Mutagenesis, Site-Directed
  • Protein Conformation*
  • Protein Isoforms / genetics


  • Apolipoprotein E3
  • Apolipoprotein E4
  • Protein Isoforms