ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Rigid and flexible geometry calculations are described for N-acetylglycine-N′-methylamide, N-acetylalanine-N′-methylamide, and their retro-inverso analogs, bis(acetamido) methane, 1,1-bis(acetamido) ethane, N,N′-dimethylmalonamide, and N,N′-dimethyl-2-methyl-malonamide. The significance of relaxing all degrees of freedom, especially angular flexibility is demonstrated. The flexible geometry approach yields energy maps similar to those from rigid geometry, but the energy barriers between minima are substantially reduced, leading in general, to more probable transitions and a higher volume of accessible conformational space. Whereas the glycine and alanine derivatives exhibit their lowest energy minima in the Ceq7 region, the gem-diaminoalkyl and malonyl residues show their lowest minima in the “α-helical” regions. With respect to the effect of side chains (H versus CH3), the greatest conformational influence appears with the gem-diaminoalkyl residues. These results indicate significantly different conformational behavior of retro peptides and the implications of these pairwise incorporations of retro-inverso residues in peptide chains, are discussed.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360220806
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