ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The synthesis of a series of protected tetrapeptides of the general formula Cbz-Gly-X2-Y3-Gly-OR (R = stearyl or methyl, X and/or Y = proline) is described. Detailed CD studies have been performed to evaluate the contribution of proline-containing β-turns to the CD spectra of proteins. The CD spectra of all the models are dominated by the chiral contribution of the proline residue. In polar, proton-donating solvents, a poly-proline II-like spectrum was observed in almost all cases. The tetrapeptide model Cbz-Gly-Gly-Pro-Gly-OStearyl, in acetonitrile shows a type C spectrum that has not been previously reported for linear peptides. The ir and nmr data on this model support the assumption of that of a type III β-turn, exhibiting a type C spectrum, participate in the conformational equilibrium. The most interesting finding of the CD studies is the observation of a type D spectrum (according to the classification of Woody [Woody, R. W. (1974) in Peptides, Polypeptides and Proteins, Blout, E. R. Bovey, F. A. Lotan, N. & Goodman, M. (Eds.), Wiley, New York]) for models Cbz-Gly-Pro-Asp(OBut)-Gly-OStearyl and Cbz-Gly-Pro-Ser(OBut)-Gly-OStearyl in cyclohexane. The results of the CD measurements ae discussed in correlation with ir and nmr data and with recent literature.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360240117
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