The decapeptide pBrBz-(Aib)10-OtBu, synthesized by the 5 (4H)-oxazolone method, crystallizes in the monoclinic space group C2/c with a = 43.901(2), b = 9.289(2), and c = 34.746(3) Å; beta = 114.69(3)-degrees; and Z = 8. The crystals contain one molecule of water associated with each peptide. The structure has been solved by the Patterson method and refined to an R value of 0.073 for 6819 observed reflections. The peptide adopts a regular 3(10)-helical structure stabilized by eight N-H...O = C intramolecular 1 <-- 4 [or C(10)] H-bonds. This study has allowed us to characterize this important peptide secondary structure in great detail. The crystal-state conformation agrees well with proposals made on the basis of an ir absorption and 1H-nmr study in solution.
Preferred conformation of the terminally blocked (Aib)10 homo-oligopeptide: a long, regular 3(10)-helix
M Crisma;
1991
Abstract
The decapeptide pBrBz-(Aib)10-OtBu, synthesized by the 5 (4H)-oxazolone method, crystallizes in the monoclinic space group C2/c with a = 43.901(2), b = 9.289(2), and c = 34.746(3) Å; beta = 114.69(3)-degrees; and Z = 8. The crystals contain one molecule of water associated with each peptide. The structure has been solved by the Patterson method and refined to an R value of 0.073 for 6819 observed reflections. The peptide adopts a regular 3(10)-helical structure stabilized by eight N-H...O = C intramolecular 1 <-- 4 [or C(10)] H-bonds. This study has allowed us to characterize this important peptide secondary structure in great detail. The crystal-state conformation agrees well with proposals made on the basis of an ir absorption and 1H-nmr study in solution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
