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Crystallographic structure of a multiple β‐turn containing, glycine‐rich heptapeptide: A synthetic precursor of the lipopeptaibol antibiotic Trichodecenin I
Author(s) -
Monaco Vania,
Formaggio Fernando,
Crisma Marco,
Toniolo Claudio,
Shui Xiuqi,
Eggleston Drake S.
Publication year - 1996
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/(sici)1097-0282(199607)39:1<31::aid-bip4>3.0.co;2-w
Subject(s) - chemistry , monoclinic crystal system , stereochemistry , crystal structure , crystallography , residue (chemistry) , molecule , sequence (biology) , conformational isomerism , peptide , nuclear magnetic resonance spectroscopy , organic chemistry , biochemistry
In continuation of our studies on the structure and function of peptaibol antibiotics, the conformational properties of a sequence analogous to that of Trichodecenin I (Z‐Gly‐Gly‐ D ‐Leu‐Aib‐Gly‐ D ‐Ile‐ D ‐Leu‐OMe, where Z = benzyloxycarbonyl, Aib = α‐aminoisobutyric acid, and OMe = methyl ester) have been investigated crystallographically. This sequence is the mirror image of the naturally occurring molecule and also of the C‐terminal heptapeptide of the related lipo‐peptaibol Trichogin A IV (where, however, the Leu‐OMe residue has replaced the original Leuol residue). The molecule crystallized in the monoclinic system, space group P2 1 , Z = 4, and cell parameters a = 11.610(5), b = 33.342(8), c = 11.735(4) Å, β = 110.42(1)*, V = 4257(3) Å 3 . The crystallographic refinement converges at residual values of R = 0.047 and wR 2 = 0.134 on F 2 . In the 1–5 segment the molecular conformation is virtually identical to that one reported from solution nmr studies of a similarly protected sequence [Biopolymers (1995), Vol. 35, pp. 21–29)] and is characterized by β‐turns of type I at Gly1‐Gly2, II′ at Leu3‐Aib4, and I at Aib4‐Gly5. In the crystal structure, a β‐sheet‐like arrangement is seen at the C‐terminus. © 1996 John Wiley & Sons, Inc.