Conformation for a beta-cyclodextrin monosubstituted with a cyclic dipeptide.
AUTOR(ES)
Di Blasio, B
RESUMO
The structural characterization of a beta-cyclodextrin monosubstituted with the peptide cyclo(L-His-L-Leu) is reported. This work provides an x-ray example of a covalently bound group that folds in such a way that the terminal apolar side chain is retained in the hydrophobic interior of the cone-shaped cyclodextrin cavity. 6-Deoxy-6-cyclo(L-histidyl-L-leucyl)-beta-cyclodextrin crystallizes in the space group P1 with cell dimensions a = 14.728(8) A, b = 15.084(7) A, c = 18.182(10) A, alpha = 94.36(6) degrees, beta = 95.81(5) degrees, gamma = 116.08(9) degrees; overall isotropic agreement R = 10.6% for 5703 observed reflections (Fo greater than 3 sigma). The molecular structure consists of two independent molecules with the formula C54H86N4O36.7.25H2O. Each molecule assumes a "sleeping swan"-like overall shape with the hydrophobic leucine side chain inserted inside the cavity of the macrocycle. The two independent units give rise to a head-to-tail dimer linked by hydrogen bonds occurring between primary and secondary hydroxyl groups of the two monomers. The packing of the dimers produces cavities containing water molecules. There are infinite hydrophilic channels running in the crystal, which is similar to what is found in the structures of cyclic peptides.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=49677Documentos Relacionados
- Chlorhexidine: beta-cyclodextrin inhibits yeast growth by extraction of ergosterol
- Sustained inhibition of intimal thickening. In vitro and in vivo effects of polymeric beta-cyclodextrin sulfate.
- Avaliação de formulações anestésicas de tetracaína em beta-ciclodextrina e hidroxipropil beta-ciclodextrina
- Effect of heptakis (2,6-O-dimethyl) beta-cyclodextrin on the production of pertussis toxin by Bordetella pertussis.
- Biotransformation of Benzaldehyde to L-Phenylacetylcarbinol (L-PAC) by Free Cells of Torulaspora delbrueckii in presence of Beta-Cyclodextrin