Amino acid sequence of COOH-terminal 20K Da fragment from pig liver microsomal NADPH-cytochrome P-450 reductase.
Biochem Biophys Res Commun
; 127(1): 94-8, 1985 Feb 28.
Article
em En
| MEDLINE
| ID: mdl-3919729
We have determined the complete amino acid sequence of a 20K Da COOH-terminal fragment of porcine NADPH-cytochrome P-450 reductase. The 20K Da fragment is probably produced by a proteolytic cleavage of the intact protein in porcine liver microsomes, and since the cleavage does not affect enzymatic activity, the fragment has been studied as a distinct domain. The sequence comprises 175 amino acids including three cysteine residues, one of which has been previously identified as protected by NADPH from S-carboxymethylation. The NADPH-protected cysteine lies in a stretch of 12 residues with partial homology to glutathione reductase, and is adjacent to a hydrophobic region containing a glycine-rich stretch homologous to other FAD-containing proteins. The predicted secondary structure over this entire region is beta-sheet/beta-turn/beta-sheet/alpha-helix/beta-sheet/beta-turn/alpha-h elix corresponding to hydrophobic residues 21-28/glycine-rich residues 29-33/residues 34-38/residues 39-54/residues 56-61/NADPH-protected cysteine residues 62-78/residues 71-82. It is possible that the 20K Da domain provided a significant portion of the sequence responsible for binding FAD and NADPH in the intact enzyme. This data provides a basis for further active site studies.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Microssomos Hepáticos
/
NADPH-Ferri-Hemoproteína Redutase
Limite:
Animals
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
1985
Tipo de documento:
Article