scholarly journals Preparation and general properties of a soluble adenosine triphosphatase from mitochondria

1967 ◽  
Vol 105 (1) ◽  
pp. 279-288 ◽  
Author(s):  
M J Selwyn
Keyword(s):  
Adenosine Triphosphatase ◽  
Metal Cations ◽  
Coupling Factor ◽  
Heart Mitochondria ◽  
Aqueous Extracts ◽  
Bivalent Metal ◽  
Adenosine Triphosphatase Activity ◽  
General Properties ◽  
Kinetics Of

1. The purification of an adenosine triphosphatase present in aqueous extracts of acetone-dried ox-heart mitochondria is described. 2. No evidence was found for the presence of more than one protein having adenosine-triphosphatase activity in these extracts. 3. The enzyme is less stable at 0° than at 25° but is stabilized by glycerol. 4. The activity is dependent on the presence of Mg2+ or certain other bivalent metal cations. 5. The adenosine-triphosphatase activity of the Mg2+-activated enzyme is enhanced by 2,4-dinitrophenol. 6. The kinetics of Mg2+ activation indicate that the ATP–Mg2+ complex is the important substrate: free ATP and Mg2+ are inhibitory. 7. This preparation of mitochondrial adenosine triphosphatase has many properties in common with the adenosine triphosphatase coupling factor from mitochondria (Racker, 1961).

scholarly journals Involvement of the endogenous inhibitor protein in the MgATP-induced inhibition of soluble mitochondrial adenosine triphosphatase activity

1981 ◽  
Vol 200 (3) ◽  
pp. 655-661 ◽  
Author(s):  
P N Lowe ◽  
R B Beechey
Keyword(s):  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Heart Mitochondria ◽  
Inhibitor Protein ◽  
Endogenous Inhibitor ◽  
Adenosine Triphosphatase Activity

Chloroform-released ATPase from ox heart mitochondria contains significant amounts of inhibitor protein. There is a correlation between processes that affect the interactions between the inhibitor protein and the ATPase molecule and the ability of MgATP to induce an inhibition of ATPase activity. Evidence is presented suggesting that the endogenous inhibitor protein is involved in the process of MgATP-induced inhibition of soluble ATPase activity.

scholarly journals Chemical modification of a cerebral sodium-plus-potassium ion-stimulated adenosine triphosphatase preparation

1970 ◽  
Vol 119 (3) ◽  
pp. 377-385 ◽  
Author(s):  
I. Pull
Keyword(s):  
High Speed ◽  
Adenosine Triphosphatase ◽  
Total Phospholipid ◽  
Amino Groups ◽  
Amide Bonds ◽  
Adenosine Triphosphatase Activity ◽  
Acid Reaction ◽  
Acid Anhydrides ◽  
Kinetics Of ◽  
Hydrolysis Of

1. A particulate Na++K+-stimulated adenosine triphosphatase preparation obtained by treatment of bovine cerebral microsomes with a sodium iodide reagent has been further treated with acid anhydrides likely to convert amino groups into acidic derivatives. 2. The extent of acylation of amino groups was determined by reaction of the remaining amino groups with 2,4,6-trinitrobenzenesulphonic acid. The unmodified preparation contains about 1.2 μequiv. of amino groups/mg of protein of which only about 0.5 μequiv. are accounted for by protein amino groups. Kinetics of the trinitrobenzenesulphonic acid reaction with the unmodified preparation are complex and are altered by ATP or ouabain. 3. The compounds examined cause loss of Na++K+-stimulated adenosine triphosphatase activity when relatively few amino groups are modified but ATP was found to afford partial protection against inactivation by methylmaleic anhydride. Na++K+-stimulated adenosine triphosphatase activity is partly restored to the dimethylmaleylated preparation by hydrolysis of the dimethylmaleyl–amide bonds but not if more than about 20% of the amino groups have been acylated. 4. Supernatants obtained by high-speed centrifugation of the dimethylmaleylated preparation contained up to 45% of the total protein with less than 10% of the total phospholipid. Methylmaleyl and benzenetricarboxylyl derivatives of the enzyme preparation behaved similarly but tetrafluorosuccinylated material was almost entirely deposited by centrifugation.

scholarly journals Inhibition of adenosine triphosphatase activity of chloroplast coupling factor (CF1 ) by troponin component, TN-I

FEBS Letters ◽  
1975 ◽  
Vol 56 (2) ◽  
pp. 248-251 ◽  
Author(s):  
Shojiro Yamazaki ◽  
Haruhiko Takisawa ◽  
Yutaka Tamaura ◽  
Shigehisa Hirose ◽  
Yuji Inada
Keyword(s):  
Adenosine Triphosphatase ◽  
Coupling Factor ◽  
Adenosine Triphosphatase Activity ◽  
Chloroplast Coupling Factor ◽  
Chloroplast Coupling Factor Cf1
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