| Retro-enantiomeric [gammaCONH]-achatin-I
(gamma-reach)
H-D-Asp-[gammaCONH]-D-Ala-L-Phe-Gly-OH 
Date: Oct.1999 |
 gamma-reach  achatin-I This structer was produced by RasMol, and stucked by GifBuilder 0.5 (Yves Piguet, 1997) |
ORTEP-III (Burnett, 1996)
drawing is left.We have tried the retro-enantiomeric (RE) modification to mimic the parent conformation by reversing sequence and using enantiomeric amino acids (Doi, M. et al., Life Sci., 56, 1557-1562, 1995) and it was applied for achatin-I (H-Gly-D-Phe-Ala-Asp-OH). Achatin-I was isolated from the ganglia of an African giant snail and is the first example of the endogenous neuropeptide having a D-amino acid (Kamatani, Y. et al., Biochem. Biophys. Res. Commun., 160, 1015-1020, 1989). A \b-turn conformation has been revealed for achatin-I (Kamatani et al., FEBS Lett., 276, 95-97, 1990).
In the chemical syntheses of the RE analogues of achatin-I, an additional trial was applied, where the linkage of a gamma-amide bond was made at the D-Asp^1^ residue. The RE-modified achatin-I (H-D-Asp-D-Ala-Phe-Gly-OH) and [gammaCONH]-RE-achatin-I (H-D-Asp-[gammaCONH]-D-Ala-Phe-Gly-OH; gamma-REACH) were subjected into crystallization, and crystals of the later peptide were obtained from a dimethylformamide-water solution.
Paper: beta-Turn structure of a retro-enantiomeric analogue of achatin-I, H-D-Asp-[gammaCONH]-D-Ala-L-Phe-Gly-OH
Mitsunobu Doi, Akiko Asano, Toshimasa Ishida, Hiroyuki Minakata & Kyosuke Nomoto
Acta Crystallogr., Sect.C, 55, 422-424 (1999)
X-Ray Data Summary
| formula | C18 H24 N4 O7 | ||
| weight | 408.41 | ||
| symmetry | orthorhombic | ||
| space group | P212121 | ||
| Cell | Crystal | ||
| a | 16.517(3) Ang. | description | needle |
| b | 23.533(5) Ang. | colour | Colorless |
| c | 5.1124(6) Ang. | size (mm) | 0.66x0.12x0.12 |
| alpha | 90.0 deg. | Dx (g/ml) | 1.365 |
| beta | 90.0 deg. | F(000) | 864 |
| gamma | 90.0 deg. | mu(CuKa) | 0.897 |
| volume | 1987.2(6) Ang^3 | ||
| Z | 4 | ||
| Diffrn measurement | Refinementspace | ||
| device type | Rigaku AFC5R/RU-200 | Flack | ? |
| decay | -1.2 % | parameters | 266 |
| index limit | 0-h-19, -27-k-27, 0-L-5 | restraints | 0 |
| theta (deg.) | 3.27-64.61 | R_factor_gt | 0.0450 |
| total reflections | 3910 include Friedel pairs | wR_factor_gt | 0.1046 |
| reflections(obs) | 3107 .gt. 2sigma(I) | dela rho_max | 0.299 e A^3 |
| Structure | delta rho_min | -0.298 e A^3 | |
| solution | SHELXL-97 | shift/su_max | lt. 0.001 |
| refinement | SHELXL-97 | Goodness of fit | 1.134 |
Get PDB coordinates of gamma-Reach
Get PDB coordinates of achatin-I
Back to the structure index
