The roles of cytochrome b5 in reconstituted monooxygenase systems containing various forms of hepatic microsomal cytochrome P-450

Journal of Biochemistry
Y Imai

Abstract

The roles of cytochrome b5 in NADPH-dependent monooxygenase reactions catalyzed by reconstituted systems containing four forms of hepatic microsomal cytochrome P-450, i.e. P-450(1), P-450(2), P-448(1), and P-448(2), were examined. Various substrates were metabolized actively in the absence of cytochrome b5 by the system containing P-450(1), but the monooxygenase reactions were accompanied by oxidation of NADPH uncoupled to the product formation. When cytochrome b5 was included in the system, the product formation increased to various extents, depending on the substrates used, while NADPH oxidation changed much less, resulting in an improvement of the coupling efficiency. The increase was large when a substrate metabolized at a low velocity was employed. Evidence is presented that the second of two electrons required for the monooxygenase reactions could be introduced into P-450(1) via cytochrome b5. On the other hand, the rate of P-450(1) reduction was not affected by the addition of cytochrome b5 to the system and that of cytochrome b5 reduction by NADPH-cytochrome P-450 reductase was sufficient to support electron flow to cytochrome P-450 via cytochrome b5 as the second electron. The stimulatory effect of cytochrome b5 on the...Continue Reading

Citations

Jan 1, 1991·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·J BlanckK Ruckpaul
Nov 1, 1996·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·H YamazakiT Shimada
Aug 26, 2004·Antimicrobial Agents and Chemotherapy·K M RogersM Bard
Nov 1, 1982·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·F P GuengerichL S Kaminsky
Jun 13, 1994·FEBS Letters·Y OmataF K Friedman
Jan 1, 1994·Archives of Insect Biochemistry and Physiology·M Zhang, J G Scott
Mar 11, 2000·Drug Metabolism Reviews·R Kato, Y Yamazoe
Jul 14, 1998·Antimicrobial Agents and Chemotherapy·K VenkateswarluS L Kelly
May 28, 1992·Biochemical Pharmacology·S S ParkH V Gelboin
Feb 1, 2003·Pharmacology & Therapeutics·John B Schenkman, Ingela Jansson
Jan 1, 1991·The International Journal of Biochemistry·T Güray, E Arinç
Aug 31, 1981·Biochemical and Biophysical Research Communications·J CapdevilaR W Estabrook
Oct 1, 1990·Archives of Biochemistry and Biophysics·R P GuptaM B Abou-Donia
Dec 1, 1982·Food and Chemical Toxicology : an International Journal Published for the British Industrial Biological Research Association·M H Siess, M F Vernevaut

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.