scholarly journals Comparison of purified bovine heart and rat liver 6-phosphofructo-2-kinase. Evidence for distinct isoenzymes

1985 ◽  
Vol 231 (1) ◽  
pp. 193-196 ◽  
Author(s):  
M H Rider ◽  
D Foret ◽  
L Hue
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Liver Enzyme ◽  
Rat Liver ◽  
Rat Heart ◽  
Kinetic Properties ◽  
Dependent Protein Kinase ◽  
Bovine Heart ◽  
Dependent Protein

Rat liver and bovine heart 6-phosphofructo-2-kinase were purified by the same procedure. Compared with the liver enzyme, the heart enzyme had a smaller apparent Mr, different kinetic properties, was not inactivated by cyclic AMP-dependent protein kinase, and contained less fructose-2,6-bisphosphatase activity. These differences suggest that heart and liver 6-phosphofructo-2-kinase are distinct isoenzymes. Likewise, 6-phosphofructo-2-kinase from rat heart and skeletal muscle was not inactivated on treatment with cyclic AMP-dependent protein kinase.

scholarly journals Antiserum against the catalytic subunit of adenosine 3′:5′-cyclic monophosphate-dependent protein kinase. Reactivity towards various protein kinases

1980 ◽  
Vol 192 (1) ◽  
pp. 223-230 ◽  
Author(s):  
G Schwoch ◽  
A Hamann ◽  
H Hilz
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Kinases ◽  
Rat Liver ◽  
Catalytic Subunit ◽  
Type Ii ◽  
Dependent Protein Kinase ◽  
Subunit C ◽  
Bovine Heart ◽  
Dependent Protein

An antiserum against the catalytic subunit C of cyclic AMP-dependent protein kinase, isolated from bovine heart type II protein kinase, was produced in rabbits. Reaction of the catalytic subunit with antiserum and separation of the immunoglobulin G fraction by Protein A-Sepharose quantitatively removed the enzyme from solutions. Comparative immunotitration of protein kinases showed that the amount of antiserum required to eliminate 50% of the enzymic activity was identical for pure catalytic subunit, and for holoenzymes type I and type II. The reactivity of the holoenzymes with the antiserum was identical in the absence or the presence of dissociating concentrations of cyclic AMP. Most of the holoenzyme (type II) remains intact when bound to the antibodies as shown by quantification of the regulatory subunit in the supernatant of the immunoprecipitate. Titration with the antibodies also revealed the presence of a cyclic AMP-independent histone kinase in bovine heart protein kinase I preparations obtained by DEAE-cellulose chromatography. Cyclic AMP-dependent protein kinase purified from the particulate fraction of bovine heart reacted with the antiserum to the same degree as the soluble enzyme, whereas two cyclic AMP-independent kinases separated from the particle fraction neither reacted with the antiserum nor influenced the reaction of the antibodies with the cyclic AMP-dependent protein kinase. Immunotitration of the protein kinase catalytic subunit C from rat liver revealed that the antibodies had rather similar reactivities towards the rat liver and the bovine heart enzyme. This points to a relatively high degree of homology of the catalytic subunit in mammalian tissues and species. Broad applicability of the antiserum to problems related to cyclic AMP-dependent protein kinases is thus indicated.

scholarly journals Effects of phosphorylation on the kinetic properties of rat liver fructose-1,6-bisphosphatase

1984 ◽  
Vol 222 (1) ◽  
pp. 125-130 ◽  
Author(s):  
D W Meek ◽  
H G Nimmo
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Rat Liver ◽  
Kinetic Properties ◽  
Purification Procedure ◽  
Dependent Protein Kinase ◽  
Fructose 1,6 Bisphosphatase ◽  
Dependent Protein ◽  
A Subunit ◽  
Fructose 1,6 Bisphosphate

A new purification procedure for rat liver fructose-1,6-bisphosphatase that involves use of Procion Red-Sepharose is described. The purified enzyme was homogeneous, had a subunit Mr of 40 000-41 000 and seemed to be undegraded. The enzyme could be phosphorylated by cyclic AMP-dependent protein kinase with a stoicheiometry of one per subunit. Phosphorylation caused a 2-fold decrease in the Km of the enzyme for fructose 1,6-bisphosphate, but did not affect its allosteric responses to AMP, Mg2+ and fructose 2,6-bisphosphate.

scholarly journals The phosphorylation of troponin I from cardiac muscle

1975 ◽  
Vol 149 (3) ◽  
pp. 525-533 ◽  
Author(s):  
H A Cole ◽  
S V Perry
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Cardiac Muscle ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Cardiac Troponin I ◽  
Phosphorylase Kinase ◽  
Dependent Protein Kinase ◽  
Dependent Protein

1. Troponin I isolated from fresh cardiac muscle by affinity chromatography contains about 1.9 mol of covalently bound phosphate/mol. Similar preparations of white-skeletal-muscle troponin I contain about 0.5 mol of phosphate/mol. 2. A 3':5'-cyclic AMP-dependent protein kinase and a protein phosphatase are associated with troponin isolated from cardiac muscle. 3. Bovine cardiac 3':5'-cyclic AMP-dependent protein kinase catalyses the phosphorylation of cardiac troponin I 30 times faster than white-skeletal-muscle troponin I. 4. Troponin I is the only component of cardiac troponin phosphorylated at a significant rate by the endogenous or a bovine cardiac 3':5'-cyclic AMP-dependent protein kinase. 5. Phosphorylase kinase catalyses the phosphorylation of cardiac troponin I at similar or slightly faster rates than white-skeletal-muscle troponin I. 6. Troponin C inhibits the phosphorylation of cardiac and skeletal troponin I catalysed by phosphorylase kinase and the phosphorylation of white skeletal troponin I catalysed by 3':5'-cyclic AMP-dependent protein kinase; the phosphorylation of cardiac troponin I catalysed by the latter enzyme is not inhibited.

scholarly journals The inhibitor protein of the cyclic AMP-dependent protein kinase-catalytic subunit interaction. Composition of multiple complexes

1988 ◽  
Vol 256 (3) ◽  
pp. 785-789 ◽  
Author(s):  
S M Van Patten ◽  
A Hotz ◽  
V Kinzel ◽  
D A Walsh
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Catalytic Subunit ◽  
Inhibitor Protein ◽  
Multiple Forms ◽  
Subunit Interaction ◽  
Dependent Protein Kinase ◽  
Bovine Heart ◽  
Dependent Protein ◽  
Multiple Species

It has been previously demonstrated that the combination of pure preparations of the inhibitor protein of the cyclic AMP-dependent protein kinase and the catalytic subunit of this enzyme resulted in the formation of multiple complexes [Van Patten, Fletcher & Walsh (1986) J. Biol. Chem. 261, 5514-5523]. In the present study it is demonstrated that these multiple species occur because the bovine heart protein kinase preparation contains multiple forms of catalytic subunit [Kinzel, Hotz, König, Gagelmann, Pyerin, Reed, Köbler, Hofmann, Obst, Gensheimer, Goldblatt & Shaltiel (1987) Arch. Biochem. Biophys. 253, 341-349].

scholarly journals Glucose-stimulated protein phosphorylation in the pancreatic islet

1984 ◽  
Vol 220 (2) ◽  
pp. 529-537 ◽  
Author(s):  
J R Colca ◽  
N Kotagal ◽  
P E Lacy ◽  
C L Brooks ◽  
L Norling ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Islet Cell ◽  
Cell Protein ◽  
Dependent Protein Kinase ◽  
Cell Homogenate ◽  
Dependent Protein ◽  
Cell Cytosol ◽  
Hexose Phosphates

A glucose-dependent phosphorylation of a 68kDa islet-cell protein was observed in islet-cell homogenates. In the presence of [gamma-32P]ATP the protein was phosphorylated only in the presence of alpha-D-glucose; other sugars were ineffective. Activation of the phosphorylation was half-maximal at 0.34 mM-glucose, 7 microM-ATP and 0.3 mM-Mg2+. Although the addition of glucose 6-phosphate in this design did not stimulate phosphorylation of the islet-cell protein, addition of glucose 6-phosphate to the radioactively labelled 68kDa protein rapidly removed (chased) the 32P label. The addition of presynthesized glucose 6-[32P]phosphate phosphorylated the 68kDa band in the islet-cell homogenate and also phosphorylated purified skeletal-muscle phosphoglucomutase. Phosphoglucomutase labelled thus by 32P was indistinguishable from the islet-cell phosphoprotein on electrophoretic gels. The 32P incorporated into both the islet-cell protein and the purified skeletal-muscle phosphoglucomutase was chased similarly by hexose phosphates. The purified phosphoglucomutase could also be phosphorylated by cyclic AMP-dependent protein kinase or by a mannoheptulose-insensitive process by the islet-cell cytosol. The phosphoenzyme formed thus was also dephosphorylated by D-glucose 6-phosphate and alpha-D-glucose 1-phosphate, suggesting that this may be a mechanism for generation of glucose 1,6-bisphosphate.

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