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Title: Partial purification of benzene hydroxylase activity from rat liver mitoplasts

Benzene is a hemopoietic toxin and a carcinogen which causes aplastic anemia and leukemia in humans and leukemia and certain solid tumors in rodents. Bioactivation of benzene is required for toxicity and, presumably, carcinogenicity. The authors have demonstrated that rat liver mitochondria, stripped of outer membrane to avoid microsomal contamination (mitoplasts), metabolize benzene in an NADPH-dependent reaction to compounds capable of covalently binding to mitochondrial DNA. They report here on the partial purification of a benzene hydroxylase activity from rat liver mitoplasts which converts benzene to phenol and which appears to be a cytochrome P-450. The activity is solubilized with 0.4% sodium cholate and further purified by a 5-15% polyethylene glycol (PEG) fractionation. The production of (/sup 3/H)phenol from (/sup 3/H)benzene by the 5-15% PEG fraction requires an NADPH-generating system and is completely dependent on the addition of exogenous bovine adrenodoxin. Although benzene hydroxylase activity has been demonstrated in rat liver microsomes, adrenodoxin has no effect on the activity of microsomal cytochromes P-450, providing evidence that our activity is indeed of mitochondrial origin.
Authors:
; ;
Publication Date:
OSTI Identifier:
7246665
Report Number(s):
CONF-8606151-
Journal ID: CODEN: FEPRA; TRN: 86-039061
Resource Type:
Conference
Resource Relation:
Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States); Journal Volume: 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
Research Org:
Thomas Jefferson Univ., Philadelphia, PA
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; BENZENE; METABOLISM; HYDROXYLASES; ENZYME ACTIVITY; PURIFICATION; CARCINOGENESIS; CELL MEMBRANES; COVALENCE; DNA; LIVER; MITOCHONDRIA; NADP; PHENOL; PROTEINS; RATS; TRITIUM COMPOUNDS; ANIMALS; AROMATICS; BODY; CELL CONSTITUENTS; COENZYMES; DIGESTIVE SYSTEM; ENZYMES; GLANDS; HYDROCARBONS; HYDROXY COMPOUNDS; LABELLED COMPOUNDS; MAMMALS; MEMBRANES; NUCLEIC ACIDS; NUCLEOTIDES; ORGANIC COMPOUNDS; ORGANOIDS; ORGANS; OXIDOREDUCTASES; PATHOGENESIS; PHENOLS; RODENTS; VERTEBRATES 550201* -- Biochemistry-- Tracer Techniques