Crystal structures of a nonapeptide helix containing α, α‐di‐n‐butylglycine (Dbg), Boc‐G1y‐Dbg‐Ala‐Val‐Ala‐Leu‐Aib‐Val‐Leu‐OMe
- 1 May 1996
- journal article
- Published by Wiley in International Journal of Peptide and Protein Research
- Vol. 47 (5), 376-382
- https://doi.org/10.1111/j.1399-3011.1996.tb01087.x
Abstract
Two crystal structures of a nonapeptide (anhydrous and hydrated) containing the amino acid residue alpha, alpha-di-n-butylglycyl, reveal a mixed 3(10)-/alpha-helical conformation. Residues 1-7 adopt phi, psi values in the helical region, with Val(8) being appreciably distorted. The Dbg residue has phi, psi values of -40, -37 degrees and -46, -40 degrees in the two crystals with the two butyl side chains mostly extended in each. Peptide molecules in the crystals pack into helical columns. The crystal parameters are: C50H91N9O12, space group P2(1), with a = 9.789(1) A, b = 20.240(2) A, c = 15.998(3) A, beta = 103.27(1); Z = 2, R = 10.3% for 1945 data observed > 3 sigma (F) and C50H91N9O12.3H2O, space group P2(1), with a = 9.747(3) A, b = 21.002(8) A, c = 15.885(6) A, beta = 102.22(3) degrees, Z = 2, R = 13.6% for 2535 data observed > 3 sigma (F). The observation of a helical conformation at Dbg suggests that the higher homologs in the alpha, alpha-dialkylated glycine series also have a tendency to stabilize peptide helices.Keywords
This publication has 27 references indexed in Scilit:
- Peptide design. Structural evaluation of potential nonhelical segments attached to helical modules.Journal of the American Chemical Society, 1995
- Contrasting solution conformations of peptides containing α,α‐dialkylated residues with linear and cyclic side chainsPeptide Science, 1995
- β‐Turn conformations in crystal structures of model peptides containing α,α‐Di‐n‐propylglycine and α,α‐Di‐n‐butylglycinePeptide Science, 1995
- Nonstandard Amino Acids in Conformational Design of Peptides. Helical Structures in Crystals of 5-10 Residue Peptides Containing Dipropylglycine and DibutylglycineJournal of the American Chemical Society, 1994
- Facile transition between 310‐ and α‐helix: Structures of 8‐, 9‐, and 10‐residue peptides containing the ‐(Leu‐Aib‐Ala)2‐Phe‐Aib‐fragmentProtein Science, 1994
- Coexistence of Folded and Extended Conformations of a Tripeptide Containing α,α-Di-n-propylglycine in CrystalsBiochemical and Biophysical Research Communications, 1994
- Stereochemistry of peptides containing 1‐aminocycloheptane‐1‐carboxylic acid (Ac7c)International Journal of Peptide and Protein Research, 1991
- Structural versatility of peptides from C?,?-dialkylated glycines. II. An IR absorption and1H-nmr study of homo-oligopeptides from C?,?-diethylglycinePeptide Science, 1988
- Structural versatility of peptides from Cα,α‐dialkylated glycines. I. A conformational energy computation and x‐ray diffraction study of homo‐peptides from Cα,α‐diethylglycinePeptide Science, 1988
- Stereochemically constrained peptides. Theoretical and experimental studies on the conformations of peptides containing 1-aminocyclohexanecarboxylic acidJournal of the American Chemical Society, 1986