FACTORS INFLUENCING THE INHIBITORY EFFECT OF CARBON MONOXIDE ON CYTOCHROME P-450-CATALYZED MIXED FUNCTION OXIDATION REACTIONS

The effect of CO on N-, 3-, 5- and 7-hydroxylation of 2-acetamidofluorene by liver microsomal fractions from control and 3-methylcholanthrene-pretreated hamsters was studied. All hydroxylations were inhibited by CO, but the degree of inhibition was different for each hydroxylation. The ratios of CO to O2 needed for 50% inhibition of the N-, 3-, 5- and 7-hydroxylations by control preparations were 8.0:1, 8.2:1, 4.2:1 and 7.1:1 respectively and by preparations from treated animals were 4.2:1, 8.9:1, 2.3:1 and 3.2:1 respectively. These results are discussed in terms of the possible presence of more than one type of cytochrome P-450 involved in hydroxylations of 2-acetamidofluorene by liver microsomal fractions from both control and pretreated hamsters.

Download Full-text

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

Acta Endocrinologica ◽

10.1530/acta.0.1070395 ◽

1984 ◽

Vol 107 (3) ◽

pp. 395-400 ◽

Cited By ~ 9

Author(s):

Itaru Kojima ◽

Etsuro Ogata ◽

Hiroshi Inano ◽

Bun-ichi Tamaoki

Keyword(s):

Carbon Monoxide ◽

Hydroxysteroid Dehydrogenase ◽

Dependent Manner ◽

In Vitro Production ◽

Mitochondrial Preparation ◽

Final Reaction ◽

Vitro Production ◽

Dose Dependent ◽

Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

Download Full-text

Production of Carbon Monoxide by Sonication of Medium Containing Glycerol. Effect on Cytochrome P-450 Reconstituted Systems

Biological Reactive Intermediates—II - Advances in Experimental Medicine and Biology ◽

10.1007/978-1-4757-0674-1_25 ◽

1982 ◽

pp. 377-380

Author(s):

V. Luu-The ◽

Ch. Vandresse ◽

J. Cumps ◽

P. Dumont

Keyword(s):

Carbon Monoxide ◽

Cytochrome P 450

Download Full-text

Kinetic Isotope Effects in Cytochrome P-450-Catalyzed Oxidation Reactions. II. Interactions of Cytochrome P-450 with Substrates and Nadph-Cytochrome % MathType!MTEF!2!1!+-% feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabm4yayaaDa% aaaa!3700! $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{c} $$ Reductase

Alcohol and Aldehyde Metabolizing Systems-IV ◽

10.1007/978-1-4757-1419-7_11 ◽

1980 ◽

pp. 95-108 ◽

Cited By ~ 1

Author(s):

Anthony Y. H. Lu ◽

Gerald T. Miwa ◽

Susan B. West ◽

Barbara J. Hodshon ◽

William A. Garland

Keyword(s):

Isotope Effects ◽

Kinetic Isotope Effects ◽

Oxidation Reactions ◽

Nadph Cytochrome ◽

Kinetic Isotope ◽

Cytochrome P 450 ◽

Catalyzed Oxidation

Download Full-text

Deposition of gold nanoparticles on organo-kaolinite — Application in electrocatalysis for carbon monoxide oxidation

Canadian Journal of Chemistry ◽

10.1139/v11-028 ◽

2011 ◽

Vol 89 (7) ◽

pp. 845-853 ◽

Cited By ~ 9

Author(s):

Sadok Letaief ◽

Wendy Pell ◽

Christian Detellier

Keyword(s):

Carbon Monoxide ◽

Gold Nanoparticles ◽

Photoelectron Spectroscopy ◽

Fine Particles ◽

Raw Materials ◽

Carbon Monoxide Oxidation ◽

Functional Materials ◽

Metallic State ◽

Oxidation Reactions ◽

X Ray

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.

Download Full-text