Citation

Tsujita M, Ichikawa Y. Biochim. Biophys. Acta 1993; 1161(2-3): 124-130.

Copyright

(Copyright © 1993, Elsevier Publishing)

DOI

10.1016/0167-4838(93)90205-6

PMID

8431464

Abstract

Cytochrome P-450SCC (P-450 XIA1) from bovine adrenocortical mitochondria was investigated using a suicide substrate: [14C]methoxychlor. [14C]Methoxychlor irreversibly abolished the activity of the side-chain cleavage enzyme for cholesterol (P-450SCC) and the inactivation was prevented in the presence of cholesterol. The binding of [14C]methoxychlor and cytochrome P-450SCC occurred in a molar ratio of 1:1 and the cholesterol-induced difference spectrum of cytochrome P-450SCC was similar with the methoxychlor-induced difference spectrum. [14C]Methoxychlor-binding peptides were purified from tryptic-digested cytochrome P-450SCC modified with [14C]methoxychlor. Determination of the sequence of the amino-acid residues of a [14C]methoxychlor-binding peptide allowed identification of the peptide comprising the amino-terminal amino-acid residues 8 to 28.

Language: en

Keywords

Amino Acid Sequence; Animals; Binding Sites; Cattle; Cholesterol; Cholesterol Side-Chain Cleavage Enzyme; Chromatography, High Pressure Liquid; Kinetics; Methoxychlor; Molecular Sequence Data; Spectrum Analysis