Monoclinic polymorph of Boc‐Trp‐Ile‐Ala‐Aib‐Ile‐Val‐Aib‐Leu‐Aib‐Pro‐OMe(anhydrous)
- 1 June 1988
- journal article
- research article
- Published by Wiley in International Journal of Peptide and Protein Research
- Vol. 31 (6) , 567-576
- https://doi.org/10.1111/j.1399-3011.1988.tb00915.x
Abstract
The structures of two crystal forms of Boc-Trp-Ile-Ala-Aib-Ile-Val-Aib-Leu-Aib-Pro-OMe have been determined. The triclinic form (P1, Z = 1) from DMSO/H2O crystallizes as a dihydrate (Karle, Sukumar and Balaram (1986) Proc. Natl. Acad. Sci. USA 83, 9284-9288). The monoclinic form (P21, Z = 2) crystallized from dioxane is anhydrous. The conformation of the peptide is essentially the same in both crystal systems, but small changes in conformational angles are associated with a shift of the helix from a predominantly .alpha.-type to a predominantly 310-type. The r.m.s. deviation of 33 atoms in the backbone and C.beta. positions of residues 2-8 is only 0.29 .ANG. between molecules in the two polymorphs. In both space groups, the helical molecules pack in a parallel fashion, rather than antiparallel. The only intermolecular hydrogen bonding is head-to-tail between helices. There are no lateral hydrogen bonds. In the P21 cell, a = 9.422(2).ANG., b = 36.392(11).ANG., c = 10.548(2).ANG., .beta. = 111.31(2).degree. and V = 3369.3.ANG.3 for 2 molecules of C60H97N11O13 per cell.Keywords
This publication has 14 references indexed in Scilit:
- Conformation of a 16-residue zervamicin IIA analog peptide containing three different structural features: 3(10)-helix, alpha-helix, and beta-bend ribbon.Proceedings of the National Academy of Sciences, 1987
- Parallel packing of alpha-helices in crystals of the zervamicin IIA analog Boc-Trp-Ile-Ala-Aib-Ile-Val-Aib-Leu-Aib-Pro-OMe.2H2O.Proceedings of the National Academy of Sciences, 1986
- Crystal structure of the α‐helical undecapeptide Boc‐L‐Ala‐Aib‐Ala‐Aib‐Ala‐Glu(OBzl)‐Ala‐Aib‐Ala‐Aib‐Ala‐OMeBiopolymers, 1985
- Crystal structure of Boc‐Leu‐Aib‐Pro‐Val‐Aib‐Aib‐Glu(OBzl)‐Gln‐Phl × H2O, the C‐terminal nonapeptide of the voltage‐dependent ionophore alamethicinBiopolymers, 1985
- Search for a fragment of known geometry by integrated Patterson and direct methodsActa Crystallographica Section A Foundations of Crystallography, 1985
- Alamethicin and related membrane channel forming polypeptidesMolecular and Cellular Biochemistry, 1983
- The Anatomy and Taxonomy of Protein StructurePublished by Elsevier ,1981
- IUPAC-IUB Commission on Biochemical Nomenclature. Abbreviations and symbols for the description of the conformation of polypeptide chains. Tentative rules (1969)Biochemistry, 1970
- Partial structural information combined with the tangent formula for noncentrosymmetric crystalsActa Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1968
- Phase determination for colemanite, CaBO3O4(OH)3.H2OActa Crystallographica, 1958