ISSN:
1075-2617
Schlagwort(e):
X-ray crystal structure
;
gliodeliquescin
;
alamethicin
;
hypelcin
;
paracelsin
;
Ac, acetyl
;
pBrBz, para-bromobenzoyl
;
Me, methyl
;
Piv, pivaloyl
;
Z, benzyloxycarbonyl
;
tBu, tert butyl
;
TFA, trifluoroacetic acid
;
EDCI, N-ethyl-N′-(3-dimethyl-aminopropyl)-carbodiimide HOBt, 1-hydroxybenzotriazole
;
Chemistry
;
Biochemistry and Biotechnology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Ac-(Aib-Ala)3-OH (a protected segment of the peptaibols gliodeliquescin and paracelsin), Z-Leu-Aib-Val-Aib-Gly-OtBu (a segment of [Leu]7-gliodeliquescin), Z-Val-Aib-Aib-Gln-OtBu (a common segment of alamethicin, paracelsin, and hypelcin), and Ac-Aib-Pro-(Aib-Ala)2-OMe and Z-Aib-Pro-(Aib-Ala)2-OMe, which represent differently Nα-protected 1-6 segments of alamethicin and hypelcin, have been synthesized by solution methods. The crystal-state conformations of these five Aib-containing peptides have been determined by X-ray diffraction analysis. We have confirmed that the 310-helical structure is preferentially adopted by Aib-rich short peptides. An experimentally unambiguous proof for the 310→α-helix conversion has been provided by the two differently N-blocked -Aib-Pro-(Aib-Ala)2-OMe hexapeptides. The β-bend ribbon conformation, commonly observed in the (Aib-Pro)n sequential oligopeptides, is not found in the -Aib-Pro-Aib-Ala-Aib-Ala- sequence. As expected on the basis of the l-configuration of the Cα-monoalkylated residues, a right-handed helix screw sense was found in all peptides investigated. © 1998 European Peptide Society and John Wiley & Sons, Ltd.
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
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