An artificial beta-sheet that dimerizes through parallel beta-sheet interactions

J Am Chem Soc. 2007 Oct 31;129(43):13043-8. doi: 10.1021/ja073391r. Epub 2007 Oct 6.

Abstract

This Article introduces a simple chemical model of a beta-sheet (artificial beta-sheet) that dimerizes by parallel beta-sheet formation in chloroform solution. The artificial beta-sheet consists of two N-terminally linked peptide strands that are linked with succinic or fumaric acid and blocked along one edge with a hydrogen-bonding template composed of 5-aminoanisic acid hydrazide. The template is connected to one of the peptide strands by a turn unit composed of (S)-2-aminoadipic acid (Aaa). 1H NMR spectroscopic studies show that these artificial beta-sheets fold in CDCl3 solution to form well-defined beta-sheet structures that dimerize through parallel beta-sheet interactions. Most notably, all of these compounds show a rich network of NOEs associated with folding and dimerization. The compounds also exhibit chemical shifts and coupling constants consistent with the formation of folded dimeric beta-sheet structures. The aminoadipic acid unit shows patterns of NOEs and coupling constants consistent with a well-defined turn conformation. The present system represents a significant step toward modeling the type of parallel beta-sheet interactions that occur in protein aggregation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acids / chemistry
  • Cross-Linking Reagents / chemistry
  • Dimerization
  • Models, Molecular
  • Molecular Structure
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Structure, Secondary
  • Proteins / chemistry*
  • Protons
  • Succinic Acid / chemistry

Substances

  • Amino Acids
  • Cross-Linking Reagents
  • Proteins
  • Protons
  • Succinic Acid