Crystal structure of neocarzinostatin, an antitumor protein-chromophore complex.
Science
; 262(5136): 1042-6, 1993 Nov 12.
Article
en En
| MEDLINE
| ID: mdl-8235619
ABSTRACT
Structures of the protein-chromophore complex and the apoprotein form of neocarzinostatin were determined at 1.8 angstrom resolution. Neocarzinostatin is composed of a labile chromophore with DNA-cleaving activity and a stabilizing protein. The chromophore displays marked nonlinearity of the triple bonds and is bound noncovalently in a pocket formed by the two protein domains. The chromophore pi-face interacts with the phenyl ring edges of Phe52 and Phe78. The amino sugar and carbonate groups of the chromophore are solvent exposed, whereas the epoxide, acetylene groups, and carbon C-12, the site of nucleophilic thiol addition during chromophore activation, are unexposed. The position of the amino group of the chromophore carbohydrate relative to C-12 supports the idea that the amino group plays a role in thiol activation.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Cinostatina
Idioma:
En
Revista:
Science
Año:
1993
Tipo del documento:
Article