Mar 22, 1983

A cytochrome b5 electron transport chain in Tetrahymena

Biochimica Et Biophysica Acta
A P KoudelkaK A Ferguson


Tetrahymena microsomes contain cytochrome b5 and an NADH-dependent cytochrome b5 reductase, but these proteins are present at only one-tenth the levels observed in rat liver microsomes. We show that both proteins can be partially purified by techniques developed for the rat liver proteins. We can show that cyanide inhibits the rate of exhaustion of NADH, and therefore reoxidation of cytochrome b5 by microsomes, and that stearoyl CoA enhances the rate of reoxidation of the cytochrome. Also, we find that a fragment of rat liver NADH-cytochrome b5 reductase can restore NADH-dependent cytochrome b5 reduction to Tetrahymena microsomes which have been treated with N-ethylmaleimide to eliminate endogenous reductase activity. These results indicate that there is considerable resemblance between the rat and Tetrahymena systems, and that desaturation of stearoyl and oleoyl groups may occur in Tetrahymena via pathways similar to those known in liver.

Mentioned in this Paper

Biochemical Pathway
Microsomes, Liver
Cytochrome b Group

About this Paper

Trending Feeds


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.

Bone Marrow Neoplasms

Bone Marrow Neoplasms are cancers that occur in the bone marrow. Discover the latest research on Bone Marrow Neoplasms here.

IGA Glomerulonephritis

IgA glomerulonephritis is a chronic form of glomerulonephritis characterized by deposits of predominantly Iimmunoglobin A in the mesangial area. Discover the latest research on IgA glomerulonephritis here.

Cryogenic Electron Microscopy

Cryogenic electron microscopy (Cryo-EM) allows the determination of biological macromolecules and their assemblies at a near-atomic resolution. Here is the latest research.

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.

LRRK2 & Immunity During Infection

Mutations in the LRRK2 gene are a risk-factor for developing Parkinson’s disease. However, LRRK2 has been shown to function as a central regulator of vesicular trafficking, infection, immunity, and inflammation. Here is the latest research on the role of this kinase on immunity during infection.

Antiphospholipid Syndrome

Antiphospholipid syndrome or antiphospholipid antibody syndrome (APS or APLS), is an autoimmune, hypercoagulable state caused by the presence of antibodies directed against phospholipids.

Meningococcal Myelitis

Meningococcal myelitis is characterized by inflammation and myelin damage to the meninges and spinal cord. Discover the latest research on meningococcal myelitis here.

Alzheimer's Disease: MS4A

Variants within membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease by recent genome-wide association studies. Here is the latest research.