Factors affecting conformations of cyclic polypeptides in the crystalline state
β Scribed by Isabella L. Karle
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 512 KB
- Volume
- 14
- Category
- Article
- ISSN
- 0020-7608
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π SIMILAR VOLUMES
## Abstract Summary: The vast majority of headβtoβtail stereoregular crystallizable polymers with an isotactic structure generally assume a helical symmetry in the crystalline state, compatible with the regular repetition along the chain axis of isomorphous isoclined units. There are at least two c
## Abstract The postulate of geometric equivalence of the monomeric units of a tactic chain with regard to an axis (I) and the postulate that the conformation is such that the internal energy of the chain, considered as not subjected to external forces, is the lowest (II), can be applied to the pre
In marked contrast to the most favourable folded conformation, predicted from ab initio quantum mechanical calculations, the crystal structure analysis of the model system incorporating -CONH-CH2-CH2-CONH-moiety, revealed the existence of an all-ant~" conformation, characterized by the backbone tors
The conformational preferences of 12 molecular substructures in the crystalline state have been determined and compared with those predicted for relevant model compounds by ab initio molecular orbital calculations. Least-squares regression shows that there is a statistically significant correlation