Structure refinement of cyclosporin A in chloroform by using RDCs measured in a stretched PDMS-gel.
Chembiochem
; 6(9): 1672-8, 2005 Sep.
Article
em En
| MEDLINE
| ID: mdl-16138307
ABSTRACT
New developments concerning alignment media for apolar solvents like chloroform make it possible to measure anisotropic parameters such as residual dipolar couplings (RDCs) at relatively low concentrations and natural isotopic abundance. As RDCs provide structural restraints with respect to an external coordinate system, long-range structural arrangements of the time-averaged structure can be determined with high precision. The method is demonstrated on the well-studied cyclo-undecapeptide Cyclosporin A (CsA), for which crystal and conventionally derived NMR structures are available. Neither crystal nor NMR structure are consistent with heteronuclear D(CH) RDCs measured in a stretched poly(dimethylsiloxane) gel, and refinement by using the anisotropic parameter results in a highly defined structure with a slightly changed backbone conformation. The applied methods and interpretation of the structural model are discussed.
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Base de dados:
MEDLINE
Assunto principal:
Clorofórmio
/
Ciclosporina
/
Géis
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Alemanha