An artificial beta-sheet that dimerizes through parallel beta-sheet interactions.
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.
Levin
Sergiy
S
Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, USA.
Nowick
James S
JS
D000596:Amino Acids / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D019281:Dimerization; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D011522:Protons; D019802:Succinic Acid / Q000737:chemistry
D000596:Amino Acids; D003432:Cross-Linking Reagents; D011506:Proteins; D011522:Protons; D019802:Succinic Acid