ISSN:
0006-3525
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The conformational preferences of dehydroalanine (ΔAla) were examined through ab initio calculations. The geometries of the minimum energy conformations for N-formyldehydro alanilamide and N-acetyl-N′-methylamide of dehydroalanine were determined by gradient optimization at the HF/6-31G* level, and correlation corrections were examined with MP2 single-point energy calculations. Furthermore, HF/3-21G ab initio geometry optimizations were performed on nine conformations of the model tripeptide N-acetyl-N′-methylamide of didehydroalanine. The results indicate that the C5 is the lowest energy conformation at all levels of theory. However, the relative energy of the helix conformation decreases when the number of ΔAla residues in the peptide chain increases. On the other hand, significant variations of the geometry upon conformational change were observed for the three compounds investigated. These results permit to extract important conformationally dependent geometry trends. The results of this study were compared to x-ray diffraction data on single crystals of dehydroalanine-containing peptides. © 1995 John Wiley & Sons, Inc.
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/bip.360360107
