The kinetic mechanism of cyclic adenosine 3 feet, 5 feet monophosphate dependent protein kinase from bovine skeletal muscle will be determined in two parts: the order of addition of substrates and release of products and the location of slow steps along the reaction pathway. Techniques are available to obtain this information which include initial rate studies in the presence and absence of products and dead-end inhibitors, isotope exchange at equilibrium and isotope trapping. Advances in steady state kinetic theory have shown that the chemical catalytic mechanism can also be obtained using a determination of the pH variation of kinetic parameters (for example Vmax, V/K, and Ki for a substrate, inhibitor or activator), and chemical modification using specific functional reagents. It is the goal of this project to determine the mechanism of action of the protein kinase catalytic subunit. Since this enzyme is intimately involved in cellular regulation, a detailed study of its mechanism is particularly appropriate. This kind of approach has been used with success for several enzymes including hexokinase, fructokinase, creatine kinase, and aspartic aminotransferase, but only a very small number of enzymes have mechanisms which are known with any degree of certainty.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM037057-02S1
Application #
3291990
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1985-12-01
Project End
1988-09-29
Budget Start
1985-12-01
Budget End
1988-09-29
Support Year
2
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of North Texas
Department
Type
Schools of Arts and Sciences
DUNS #
City
Denton
State
TX
Country
United States
Zip Code
76203
Qamar, R; Cook, P F (1993) pH dependence of the kinetic mechanism of the adenosine 3',5'-monophosphate dependent protein kinase catalytic subunit in the direction of magnesium adenosine 5'-diphosphate phosphorylation. Biochemistry 32:6802-6
McClure Jr, G D; Qamar, R; Cook, P F (1993) A method for counting active sites of cyclic AMP-dependent protein kinase. J Enzyme Inhib 7:151-7
Qamar, R; Yoon, M Y; Cook, P F (1992) Kinetic mechanism of the adenosine 3',5'-monophosphate dependent protein kinase catalytic subunit in the direction of magnesium adenosine 5'-diphosphate phosphorylation. Biochemistry 31:9986-92
Payne, M A; Cook, P F (1991) Derivation of the rate equation for competitive double activation by effectors. J Biol Chem 266:8897-8
Payne, M A; Rao, G S; Harris, B G et al. (1991) Fructose 2,6-bisphosphate and AMP increase the affinity of the Ascaris suum phosphofructokinase for fructose 6-phosphate in a process separate from the relief of ATP inhibition. J Biol Chem 266:8891-6
Rao, G S; Cook, P F; Harris, B G (1991) Effector-induced conformational transitions in Ascaris suum phosphofructokinase. A fluorescence and circular dichroism study. J Biol Chem 266:8884-90
Rao, G S; Cook, P F; Harris, B G (1991) Modification of the ATP inhibitory site of the Ascaris suum phosphofructokinase results in the stabilization of an inactive T state. Biochemistry 30:9998-10004
Kong, C T; Cook, P F (1988) Isotope partitioning in the adenosine 3',5'-monophosphate dependent protein kinase reaction indicates a steady-state random kinetic mechanism. Biochemistry 27:4795-9
Rao, G S; Wariso, B A; Cook, P F et al. (1987) Reaction of Ascaris suum phosphofructokinase with diethylpyrocarbonate. Inactivation and desensitization to allosteric modulation. J Biol Chem 262:14068-73
Yoon, M Y; Cook, P F (1987) Chemical mechanism of the adenosine cyclic 3',5'-monophosphate dependent protein kinase from pH studies. Biochemistry 26:4118-25

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