Solid state and solution conformation of [Ala7]-phalloidin: a synthetic phallotoxin analogue.
Chemistry
; 7(7): 1479-85, 2001 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-11330902
ABSTRACT
Phallotoxins are toxic compounds produced by poisonous mushroom Amanita phalloides and belong to the class of bicyclic peptides with a transannular thioether bridge. Their intoxication mechanism in the liver involves a specific binding of the toxins to F-actin that, consequently, prevents the depolymerization equilibrium with G-actin. Even though the conformational features of phallotoxins have been worked out in solution, the exact mechanism of interaction with F-actin is still unknown. In this study a toxic phalloidin synthetic derivative, bicyclo(Ala1-D-Thr2-Cys3-cis-4-hydroxy-Pro4-Ala5-2-mercapto-Trp6-Ala7)(S-3-->6) has been synthesized. A substitution at position 7. with an Ala residue replaces the 4,5-dihydroxy-Leu present in the natural phalloidin. This analogue has formed crystals suitable for X-ray analysis, and represents the first case for such a class of compounds. The solid-state structure as well as the solution conformation have been evaluated. NMR techniques have been used to extract interproton distances as restraints in subsequent molecular dynamics calculations. Finally, a direct comparison between structures in solution and in the solid state is presented.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Faloidina
/
Amanitinas
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Itália