Coformational energy calculations on the 1-aminocyclopentane-1-carboxylic acid monopeptide Ac-Acc5-NHMe indicate that this Cα,α-dialkylated, cyclic α-amino acid residue is conformationally restricted and that its minimum energy conformation falls in the α/310-helical region. The results of the theoretical analysis are in agreement with the crystal-state structural tendency of pBrBz(Acc5)4OtBu·2MeOH, pBrBz(Acc5)5OtBu·MeOH, and Z(Acc5)6OtBu, determined by X-ray diffraction and also described in this work (formation of 310-helices). The implications for the use of Acc5 residues in designing conformationally constrained analogues of bioactive peptides are briefly discussed. © 1988.
STRUCTURAL VERSATILITY OF PEPTIDES FROM C-ALPHA,ALPHA-DIALKYLATED GLYCINES - A CONFORMATIONAL ENERGY CALCULATION AND X-RAY-DIFFRACTION STUDY OF HOMOPEPTIDES FROM 1-AMINOCYCLOPENTANE-1-CARBOXYLIC ACID
BARONE, Vincenzo;
1988
Abstract
Coformational energy calculations on the 1-aminocyclopentane-1-carboxylic acid monopeptide Ac-Acc5-NHMe indicate that this Cα,α-dialkylated, cyclic α-amino acid residue is conformationally restricted and that its minimum energy conformation falls in the α/310-helical region. The results of the theoretical analysis are in agreement with the crystal-state structural tendency of pBrBz(Acc5)4OtBu·2MeOH, pBrBz(Acc5)5OtBu·MeOH, and Z(Acc5)6OtBu, determined by X-ray diffraction and also described in this work (formation of 310-helices). The implications for the use of Acc5 residues in designing conformationally constrained analogues of bioactive peptides are briefly discussed. © 1988.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
