ORGN 631 |
| The effect of neighboring aromatic (phenylalanine, tyrosine, tryptophan, histidine) and aliphatic (leucine, valine, proline) amino acids on α-proton chemical shifts is important to understand in order to accurately predict α-helix and β-sheet structure in peptides and proteins using the Chemical Shift Index Method. These effects have been studied in pentapetides of the general structure GXaaAYaaG. It has been found that one aromatic amino acid can shift the α-proton of alanine up to 0.15 ppm upfield, and two aromatic amino acids can shift the α-proton of alanine up to 0.19 ppm upfield. The magnitude of the shift depends on the nature and position (N-terminal or C-terminal) of the amino acid. Additional studies on the α-proton chemical shift of alanine in short peptides have also shown that the effect of pH and urea are other important factors to consider when using the Chemical Shift Index Method. |
|
Proteins, Peptides, Amino Acids, and Enzyme Inhibitors
8:00 AM-12:00 PM, Thursday, 30 March 2006 Georgia World Congress Center -- C301, Oral
Division of Organic Chemistry |