ADENOSINE TRIPHOSPHATE-ADENOSINE MONOPHOSPHATE TRANSPHOSPHORYLASE (MYOKINASE)

Adenosine Triphosphate : Guanosine Monophosphate Phosphotransferase

Several laboratories have reported studies on individual enzymes that belong to the general class of adenosine triphosphate : nucleoside monophosphate phosphotransferases (EC 2.7.4.4), commonly termed nucleoside monophosphate kinases (l-7). Studies with partially purified enzyme preparations have indicated that a variety of nucleoside monophosphates can serve as alternative substrates for nucle...

Studies on adenosine triphosphate transphosphorylases. II. Amino acid composition of adenosine triphosphate-creatine transphosphorylase.

Some of the physical and chemical properties of crystalline adenosine triphosphate-creatine transphosphorylase from rabbit muscle (1) have been previously described (2). In 1956, Friedberg reported on the amino acid composition of this enzyme (3). His data, however, were derived from analyses of only two samples hydrolyzed for the same time interval. Preliminary amino acid analyses from this la...

Activation of skeletal muscle phosphorylase kinase by adenosine triphosphate and adenosine 3',5'-monophosphate.

Rabbit skeletal muscle phosphorylase kinase has been obtained as a nearly homogeneous protein showing a single peak on electrophoresis and in the ultracentrifuge. Incubation of the purified kinase with T~~P-ATP in the presence of Mg++ ions activates the enzyme; this process is accompanied by phosphorylation of the protein. Activation and phosphorylation of phosphorylase kinase occur more rapidl...

Adenosine triphosphate: adenosine monophosphate phosphotransferase isozymes in rat liver and hepatomas.

Rat liver adenosine triphosphate: adenosine monophosphate phosphotransferase activity. II. Subcellular localization of adenylate kinase isozymes.

Adenylate kinase activity (ATP:AMP-phosphotransferase, EC 2.7.4.3) was studied in subcellular extracts of rat liver tissue. Essentially all of the activity, over 150 units per g of tissue, wet weight (1.7 units per mg of protein), was released into the cytosol when the tissue was homogenized in 0.025 M sucrose. Isotonic (0.25 M sucrose) homogenization and separation of subcellular fractions by ...