Biomaterial Database

Pseudoenzymatic reduction of N-hydroxy-2-acetylaminofluorene to 2-acetylaminofluorene mediated by cytochrome P450. 1999

S Kitamura, and K Takekawa, and K Sugihara, and K Tatsumi, and S Ohta

Institute of Pharmaceutical Science, Hiroshima University School of Medicine, Japan. kitamura@pharm.hiroshima-u.ac.jp

N-hydroxy-2-acetylaminofluorene (N-OH-AAF) was reduced to 2-acetylaminofluorene by rat liver microsomes in the presence of both NAD(P)H and FAD under anaerobic conditions. The microsomal reduction proceeds as if it were an enzymatic reaction. However, when the microsomes were boiled, the activity was not abolished, but was enhanced. The activity was also observed with cytochrome P450 2B1 alone, without NADPH-cytochrome P450 reductase, in the presence of these cofactors. Hematin also exhibited a significant reducing activity in the presence of both a reduced pyridine nucleotide and FAD. The activities of microsomes, cytochrome P450 2B1 and hematin were also observed upon the addition of photochemically reduced FAD instead of both NAD(P)H and FAD. The microsomal reduction of N-OH-AAF appears to be a non-enzymatic reaction by the reduced flavin, catalyzed by the heme group of cytochrome P450.

UI	MeSH Term	Description	Entries
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D009243	NAD	A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)	Coenzyme I,DPN,Diphosphopyridine Nucleotide,Nadide,Nicotinamide-Adenine Dinucleotide,Dihydronicotinamide Adenine Dinucleotide,NADH,Adenine Dinucleotide, Dihydronicotinamide,Dinucleotide, Dihydronicotinamide Adenine,Dinucleotide, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide,Nucleotide, Diphosphopyridine
D009249	NADP	Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5'-phosphate (NMN) coupled by pyrophosphate linkage to the 5'-phosphate adenosine 2',5'-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed)	Coenzyme II,Nicotinamide-Adenine Dinucleotide Phosphate,Triphosphopyridine Nucleotide,NADPH,Dinucleotide Phosphate, Nicotinamide-Adenine,Nicotinamide Adenine Dinucleotide Phosphate,Nucleotide, Triphosphopyridine,Phosphate, Nicotinamide-Adenine Dinucleotide
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D002273	Carcinogens	Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.	Carcinogen,Oncogen,Oncogens,Tumor Initiator,Tumor Initiators,Tumor Promoter,Tumor Promoters,Initiator, Tumor,Initiators, Tumor,Promoter, Tumor,Promoters, Tumor
D006881	Hydroxyacetylaminofluorene	A N-hydroxylated derivative of 2-ACETYLAMINOFLUORENE that has demonstrated carcinogenic action.	Hydroxyfluorenylacetamide,N-Hydroxy-2-acetamidofluorene,N Hydroxy 2 acetamidofluorene
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015073	2-Acetylaminofluorene	A hepatic carcinogen whose mechanism of activation involves N-hydroxylation to the aryl hydroxamic acid followed by enzymatic sulfonation to sulfoxyfluorenylacetamide. It is used to study the carcinogenicity and mutagenicity of aromatic amines.	2-Acetamidofluorene,Fluoren-2-ylacetamide,2-AAF,2-Fluorenylacetamide,AAF, Aminofluorene,Acetylaminofluorene,N-2-Fluorenylacetamide,N-Acetyl-2-Aminofluorene,2 Acetamidofluorene,2 Acetylaminofluorene,2 Fluorenylacetamide,Aminofluorene AAF,Fluoren 2 ylacetamide,N 2 Fluorenylacetamide,N Acetyl 2 Aminofluorene
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus
D019362	Cytochrome P-450 CYP2B1	A major cytochrome P-450 enzyme which is inducible by PHENOBARBITAL in both the LIVER and SMALL INTESTINE. It is active in the metabolism of compounds like pentoxyresorufin, TESTOSTERONE, and ANDROSTENEDIONE. This enzyme, encoded by CYP2B1 gene, also mediates the activation of CYCLOPHOSPHAMIDE and IFOSFAMIDE to MUTAGENS.	BROD,Benzyloxyresorufin O-Dealkylase,CYP2B1,PROD,Pentoxyresorufin O-Dealkylase,7-Benzyloxyresorufin O-Dealkylase,7-Pentylresorufin O-Depentylase,CYP 2B1,Cytochrome P450 2B1,7 Benzyloxyresorufin O Dealkylase,7 Pentylresorufin O Depentylase,Benzyloxyresorufin O Dealkylase,Cytochrome P 450 CYP2B1,O-Dealkylase, Pentoxyresorufin,Pentoxyresorufin O Dealkylase