Adenosine phosphokinase

Mg Polynucleotide phosphoryla.ee. ATPase. choline acylase, deoxyribonuclease, acetate kinase, adenosine phosphokinase, tructokinase. glyceric kinase, hexokinase Chlorophyll... 

The terminal phosphate of ATP can be transferred to adenosine by adenosine phosphokinase purified from yeast (103-106). 

In the preceding sections the conversion of purines and purine nucleosides to purine nucleoside monophosphates has been discussed. The monophosphates of adenosine and guanosine must be converted to their di- and triphosphates for polymerization to RNA, for reduction to 2 -deoxyribonucleoside diphosphates, and for the many other reactions in which they take part. Adenosine triphosphate is produced by oxidative phosphorylation and by transfer of phosphate from 1,3-diphosphoglycerate and phosphopyruvate to adenosine diphosphate. A series of transphosphorylations distributes phosphate from adenosine triphosphate to all of the other nucleotides. Two classes of enzymes, termed nucleoside mono-phosphokinases and nucleoside diphosphokinases, catalyse the formation of the nucleoside di- and triphosphates by the transfer of the terminal phosphoryl group from adenosine triphosphate. Muscle adenylate kinase (myokinase)... 

Creatine phosphokinase activity has been reported to be minimally inhibited by hemolysis. Hemoglobin concentrations of 1.25 g/100 ml inhibit 5% and 2.5 g/100 ml, 12% (N5). However, in methods utilizing adenosine diphosphate in the reaction mixture, hemolysates containing 100 mg of hemoglobin per 100 ml may have apparent activities of 5-100 units/liter. The activity is presumably related to adenylate kinase in the erythrocyte (S33). In methods utilizing adenosine diphosphate in a coupled enzyme reaction with hexokinase and glucose-6-phosphatase, the inhibitory effect can be eliminated by adding sufficient adenosine mono-... 

Adenosine triphosphate creatine A-phosphotransferase (EC 2.7.3.2), also creatine phosphokinase. Creatine kinase is found in muscle and is responsible for the formation of creatine phosphate from creatine and adenosine triphosphate creatine phosphate is a higher energy source for muscle contraction. Creatine kinase is elevated in all forms of muscular dystrophy. Creatine kinase is dimer and is present as isozymes (CK-1, BB CK-2, MB CK-3, MM) and Ck-mt (mitochondrial). Creatine kinase is also used to measure cardiac muscle damage in myocardial infarction. See Bais, R. and Edwards, J.B., Creatine kinase, CRC Crit. Rev. Clin. Lab. ScL 16, 291-355, 1982 McLeish, M.J. and Kenyon, G.L., Relating structure to mechanism in creatine kinase, Crit. Rev. Biochem. Mol. Biol 40, 1-20, 2005. 

The three tissue enzymes known to participate in formation of the phosphate esters are (1) thiaminokinase (a pyro-phosphokinase), which catalyzes formation of TPP and adenosine monophosphate (AMP) from thiamine and adenosine triphosphate (ATP) (2) TPP-ATP phosphoryl-transferase (cytosoHc 5"-adenylic kinase)which forms the triphosphate and adenosine diphosphate from TPP and ATP and (3) thiamine triphosphatase, which hydrolyzes TPP to the monophosphate. Although thiaminokinase is widespread, the phosphoryl transferase and membrane-associated triphosphatase are mainly in nervous tissue. 

Adenosine triphosphate, ATP, phosphorylates glncose as it enters the living cell according to reaction (11.36), which can alternatively be written as (11.37). In this non-reversible reaction in which ATP acts as the phosphorylating agent, the enzyme is given a special name hexokinase (Fignre 11.14). Enzymes which catalyse transfers specifically to and from ATP (or other nucleotides) are sometimes called phosphokinases. 

These important enzymes are numerous and universally present in the biosphere. The Lohmann enzyme oi creatine-phosphokinase has been known for a long time. It catalyses the transfer of a phosphoric add residue from adenosine triphosphate to creatine (Lohmann reaction). 

Adenosine-5 -ph osphosulfate (APS) the precursor of PAPS has been synthesized by Baddiley et al. (49). Besides phosphokinase which catalyzes... 

The formation of the active CO2 (COg-biotin-protein) requires Mg", while the enzymic transfer of COi to an acceptor proceeds without this ion. The adenosine diphosphate (ADP) transfer from ATP to the biotin-protein is a novel reaction, in contrast to the better known phosphokinase type of PO4" transfers. Biotin itself can act as a COg-binding agent in the presence of the carboxyUme smd ATP, to yield a COg-biotin compound which is easOy decomposed by H. Tlie structure of the biotin-COg compound is compatible with an all( hanic acid type of molecule. 

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