Reconstitution of apo-porphobilinogen deaminase: structural changes induced by cofactor binding.
FEBS Lett
; 242(2): 319-24, 1989 Jan 02.
Article
em En
| MEDLINE
| ID: mdl-2644132
ABSTRACT
Expression of porphobilinogen deaminase in a hemB- strain of E. coli has permitted the isolation of the apoenzyme, i.e. deaminase lacking the porphobilinogen-derived dipyrromethane cofactor. Incubation of purified apoenzyme with porphobilinogen resulted in reconstitution of the covalently attached dipyrromethane cofactor, indicating no additional cofactors or enzymes are required for biosynthesis of holoenzyme. Electrophoretic and 13C-NMR spectroscopic analyses demonstrate that the apoenzyme exists in a conformationally unstable form which is converted to a highly stable tertiary structure on covalent attachment of the dipyrromethane cofactor.
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Base de dados:
MEDLINE
Assunto principal:
Porfobilinogênio
/
Hidroximetilbilano Sintase
/
Amônia-Liases
Idioma:
En
Ano de publicação:
1989
Tipo de documento:
Article