Purification and characterization of NADP-linked isocitrate dehydrogenase from the copper-tolerant wood-rotting basidiomycete Fomitopsis palustris.
Biosci Biotechnol Biochem
; 67(1): 114-20, 2003 Jan.
Article
em En
| MEDLINE
| ID: mdl-12619682
ABSTRACT
NADP-linked isocitrate dehydrogenase (EC 1.1.1.42), a key enzyme of the tricarboxylic acid cycle, was purified 672-fold as a nearly homogeneous protein from the copper-tolerant wood-rotting basidiomycete Fomitopsis palustris. The purified enzyme, with a molecular mass of 115 kDa, consisted of two 55-kDa subunits, and had the Km of 12.7, 2.9, and 23.9 microM for isocitrate, NADP, and Mg2+, respectively, at the optimal pH of 9.0. The enzyme had maximum activity in the presence of Mg2+, which also helped to prevent enzyme inactivation during the purification procedures and storage. The enzyme activity was competitively inhibited by 2-oxoglutarate (K(i), 127.0 microM). Although adenine nucleotides and other compounds, including some of the metabolic intermediates of glyoxylate and tricarboxylic acid cycles, had no or only slight inhibition, a mixture of oxaloacetate and glyoxylate potently inhibited the enzyme activity and the inhibition pattern was a mixed type.
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Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Basidiomycota
/
Cobre
/
Isocitrato Desidrogenase
Idioma:
En
Revista:
Biosci Biotechnol Biochem
Assunto da revista:
BIOQUIMICA
/
BIOTECNOLOGIA
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Japão