Open AccessConformational investigation of alpha,beta-dehydropeptides. XIII. Conformational properties of N-acetyl-alpha,beta-dehydrovaline N',N'-dimethylamide.
Author(s) -
Dawid Siodłak,
Barbara Rzeszotarska,
Małgorzata A. Broda,
Anna E. Kozioł,
Edyta Kołodziejczyk
Publication year - 2004
Publication title -
acta biochimica polonica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.452
H-Index - 78
eISSN - 1734-154X
pISSN - 0001-527X
DOI - 10.18388/abp.2004_3606
Subject(s) - beta (programming language) , chemistry , amide , crystallography , stereochemistry , ab initio , molecule , alpha (finance) , residue (chemistry) , crystal structure , mathematics , construct validity , organic chemistry , computer science , programming language , statistics , biochemistry , psychometrics
The crystal structure of Ac-DeltaVal-NMe(2) (DeltaVal = alpha,beta-dehydrovaline) was determined by X-ray crystallography. The found angles phi = -60 degrees and psi = 125 degrees correspond exactly to the respective values of the (i + 1)th residue in idealised beta-turn II/VIa. Ab initio/DFT studies revealed that the molecule adopts the angle psi restricted only to about |130 degrees | and very readily attains the angle phi = about -50 degrees. This is in line with its solid-state conformation. Taken together, these data suggest that the DeltaVal residue combined with a C-terminal tertiary amide is a good candidate at the (i + 1)th position in a type II/VIa beta-turn.