Time-resolved extrinsic fluorescence of aromatic-L-amino-acid decarboxylase.
Biochim Biophys Acta
; 996(3): 195-8, 1989 Jul 06.
Article
em En
| MEDLINE
| ID: mdl-2752045
ABSTRACT
The coenzyme-linked fluorescence of aromatic-L-amino-acid decarboxylase decays non-exponentially. The decay of both native and NaBH4 reduced samples can only be fitted by two exponentials each roughly accounting for about half of the total fluorescence. Denaturation of the reduced protein with 8 M urea makes the fluorescence decay mono-exponential, like that observed for the reference compound pyridoxamine-5-phosphate. An extra pyridoxyl moiety can be bound to the enzyme after incubation with excess pyridoxal phosphate and reduction with NaBH4. This sample is almost twice as fluorescent and shows also two lifetimes. After denaturation only one fluorescence lifetime is observed. The presence of two non-equivalent pyridoxal sites in the native enzyme can be postulated. The heterogeneous decay behaviour of the pyridoxyl moiety in the enzyme together with the variability of lifetime shown, makes this fluorophore an even more interesting fluorescent probe for proteins.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Descarboxilases de Aminoácido-L-Aromático
/
Fosfato de Piridoxal
Limite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
Itália