PMID: 141Nov 1, 1975

Characterization studies on the membrane-bound adenosine triphosphatase (ATPase) of Azotobacter vinelandii

Canadian Journal of Microbiology
P Jurtshuk, J E McEntire


The adenosinetriphosphatase (ATPase) (EC activity in Azotobacter vinelandii concentrates in the membranous R3 fraction that is directly associated with Azotobacter electron transport function. Sonically disrupted Azotobacter cells were examined for distribution of ATPase activity and the highest specific activity (and activity units) was consistently found in the particulate R3 membranous fraction which sediments on ultracentrifugation at 144 000 X g for 2 h. When the sonication time interval was increased, the membrane-bound ATPase activity could neither be solubilized nor released into the supernatant fraction. Optimal ATPase activty occurred at pH 8.0; Mg2+ ion when added to the assay was stimulatory. Maximal activity always occurred when the Mg2+:ATP stoichiometry was 1:1 on a molar ratio at the 5 mM concentration level. Sodium and potassium ions had no stimulatory effect. The reaction kinetics were linear for the time intervals studied (0-60 min). The membrane-bound ATPase in the R3 fraction was stimulated 12-fold by treatment wiTH TRypsin, and fractionation studies showed that trypsin treatment did not solubilize ATPase activity off the membranous R3 electron transport fraction. The ATPase was not cold labile and...Continue Reading


Feb 15, 1984·Archives of Biochemistry and Biophysics·G Dreyfus, M Satre

Related Concepts

DNA-dependent ATPase
Cell-Free System
Drug Stability
Respiratory Chain
Enzyme Activation
Hydrogen-Ion Concentration

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.

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.

Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis is a rare rheumatic disease that affects children. Symptoms include joint pain, but also fevers and skin rashes. Here is the latest on this disease.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Central Pontine Myelinolysis

Central Pontine Myelinolysis is a neurologic disorder caused most frequently by rapid correction of hyponatremia and is characterized by demyelination that affects the central portion of the base of the pons. Here is the latest research on this disease.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Pontocerebellar Hypoplasia

Pontocerebellar hypoplasias are a group of neurodegenerative autosomal recessive disorders with prenatal onset, atrophy or hypoplasia of the cerebellum, hypoplasia of the ventral pons, microcephaly, variable neocortical atrophy and severe mental and motor impairments. Here is the latest research on pontocerebellar hypoplasia.

Cell Atlas Along the Gut-Brain Axis

Profiling cells along the gut-brain axis at the single cell level will provide unique information for each cell type, a three-dimensional map of how cell types work together to form tissues, and insights into how changes in the map underlie health and disease of the GI system and its crosstalk with the brain. Disocver the latest research on single cell analysis of the gut-brain axis here.

Chronic Traumatic Encephalopathy

Chronic Traumatic Encephalopathy (CTE) is a progressive degenerative disease that occurs in individuals that suffer repetitive brain trauma. Discover the latest research on traumatic encephalopathy here.