Prostaglandin-H synthase mediated formation of DNA adducts from the food mutagen 2-amino-3-methyl-imidazo[4,5-f]quinoline

1995 ◽  
Vol 121 (S1) ◽  
pp. A25-A25 ◽  
Author(s):  
E. Wolz ◽  
D. Wild ◽  
G. H. Degen
Keyword(s):  
Dna Adducts ◽  
Prostaglandin H Synthase ◽  
Prostaglandin H ◽  
Food Mutagen

DNA adducts formed by ring-oxidation of the carcinogen 2-naphthylamine with prostaglandin H synthase in vitro and in the dog urothelium in vivo

1985 ◽  
Vol 6 (9) ◽  
pp. 1379-1387 ◽  
Author(s):  
Y. Yamazoe ◽  
D.W. Miller ◽  
C.C. Weis ◽  
K.L. Dooley ◽  
T.V. Zenser ◽  
...  
Keyword(s):  
Dna Adducts ◽  
Prostaglandin H Synthase ◽  
Ring Oxidation ◽  
Prostaglandin H

To the Mechanism of 2-Nitroanisole Carcinogenicity: in vitro Metabolism of 2-Nitroanisole Mediated by Peroxidasesand Xanthine Oxidase

1998 ◽  
Vol 63 (6) ◽  
pp. 857-869 ◽  
Author(s):  
Marie Stiborová ◽  
Heinz H. Schmeiser ◽  
Eva Frei
Keyword(s):  
Horseradish Peroxidase ◽  
Xanthine Oxidase ◽  
Dna Adducts ◽  
Active Oxygen Species ◽  
Radical Mechanism ◽  
Maximal Velocity ◽  
Prostaglandin H Synthase ◽  
Nuclease P1 ◽  
Prostaglandin H

The in vitro enzymatic metabolism of carcinogenic 2-nitroanisole was investigated using peroxidases (horseradish peroxidase and prostaglandin H synthase) and xanthine oxidase catalyzing oxidative and reductive reactions, respectively. The oxidation of 2-nitroanisole catalyzed by horseradish peroxidase exhibits the Michaelis-Menten kinetics. The Michaelis constant (Km) and the maximal velocity (Vmax) values for this substrate were determined at pH 5.0, 7.0, 7.6 and 8.0. At optimal pH (7.6), the Km and Vmax values are 0.219 μmol/l and 34.45 pmol/min per nmol peroxidase, respectively. The oxidation of 2-nitroanisole is inhibited by radical trapping agents (NADH, ascorbate, glutathione and nitrosobenzene). This indicates that the peroxidase-mediated oxidation of 2-nitroanisole proceeds via a radical mechanism. Active oxygen species are formed during the horseradish peroxidase-catalyzed reactions in the presence of NADH, hydrogen peroxide and 2-nitroanisole. 2-Nitroanisole is also oxidized by mammalian prostaglandin H synthase. Using the nuclease P1-enhanced variation of the 32P-postlabelling assay, the formation of DNA adducts was detected in DNA treated with 2-nitroanisole and xanthine oxidase. No DNA binding was detected after oxidation of 2-nitroanisole with horseradish peroxidase and prostaglandin H synthase. The results presented (the formation of DNA adducts after 2-nitroanisole activation by xanthine oxidase and that of radicals and/or superoxide radicals during the reactions with peroxidases) strongly suggest the participation of 2-nitroanisole both in the initiation and in the promotion phases of carcinogenesis.

scholarly journals Heme coordination of prostaglandin H synthase.

1993 ◽  
Vol 268 (12) ◽  
pp. 8554-8563
Author(s):  
A.L. Tsai ◽  
R.J. Kulmacz ◽  
J.S. Wang ◽  
Y. Wang ◽  
H.E. Van Wart ◽  
...  
Keyword(s):  
Prostaglandin H Synthase ◽  
Prostaglandin H

scholarly journals Spectral analysis of the protein-derived tyrosyl radicals from prostaglandin H synthase.

1992 ◽  
Vol 267 (33) ◽  
pp. 23583-23588 ◽  
Author(s):  
J.A. DeGray ◽  
G Lassmann ◽  
J.F. Curtis ◽  
T.A. Kennedy ◽  
L.J. Marnett ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Prostaglandin H Synthase ◽  
Tyrosyl Radicals ◽  
Prostaglandin H

In vitro inhibition of prostaglandin H synthase by compounds from the exocrine secretions of lace bugs

1989 ◽  
Vol 93 (2) ◽  
pp. 253-255 ◽  
Author(s):  
Russell A. Jurenka ◽  
John W. Neal ◽  
Ralph W. Howard ◽  
James E. Oliver ◽  
Gary J. Blomquist
Keyword(s):  
Prostaglandin H Synthase ◽  
Exocrine Secretions ◽  
Lace Bugs ◽  
In Vitro Inhibition ◽  
Prostaglandin H
Sign in / Sign up

Export Citation Format

Share Document