Influence of exercise on the distribution of enzymes in trout white muscle and kinetic properties of AMP-deaminase from free and bound fractions

1994 ◽  
Vol 13 (5) ◽  
pp. 407-418 ◽  
Author(s):  
V. I. Lushchak ◽  
K. B. Storey
Keyword(s):  
White Muscle ◽  
Kinetic Properties ◽  
Amp Deaminase

scholarly journals Kinetic properties of AMP deaminase in acute experimental pancreatitis.

1994 ◽  
Vol 41 (2) ◽  
pp. 158-160
Author(s):  
E Kossowska ◽  
J Purzycka-Preis ◽  
M Woźniak ◽  
M Zydowo ◽  
Z Sledźiński
Keyword(s):  
Experimental Pancreatitis ◽  
Kinetic Properties ◽  
Amp Deaminase ◽  
Acute Experimental Pancreatitis

Control of energy metabolism in fish white muscle

1976 ◽  
Vol 230 (3) ◽  
pp. 579-582 ◽  
Author(s):  
WR Driedzic ◽  
PW Hochachka
Keyword(s):  
Energy Metabolism ◽  
Pyruvate Kinase ◽  
White Muscle ◽  
Maximal Activity ◽  
Glycolytic Flux ◽  
Amp Deaminase ◽  
Atp Levels ◽  
Adenylate Pool

Concentrations of key metabolites were determined in carp white muscle before exercise and after maximal activity. It was found that the concentration of ATP decreases by about 65%, ADP decreases slightly, and AMP remains unchanged. Consequently, the level of the free adenylate pool decreases. Simultaneously there is an increase in the concentration of IMP and NH4+. The increase in IMP level and the decrease in adenylate pool are essentially in 1:1 stoichiometry, a result showing that the adenylate pool is decreased by the reaction catalyzed by 5'-AMP deaminase (EC 3.5.4.6 .). During exercise there is an increase in levels of glucose-6-phosphate, fructose 6-phosphate, and fructose 1,6-diphosphate that, along with the decrease in ATP levels, can account for the increase in glycolytic flux by activation of phosphofructokinase and pyruvate kinase.

scholarly journals Inactivation of rat muscle 5′-adenylate aminohydrolase by tyrosine nitration with tetranitromethane

1981 ◽  
Vol 193 (3) ◽  
pp. 853-859
Author(s):  
M Ranieri-Raggi ◽  
C Bergamini ◽  
U Montali ◽  
A Raggi
Keyword(s):  
Enzyme Activity ◽  
Kinetic Properties ◽  
Tyrosine Nitration ◽  
Amp Deaminase ◽  
Thiol Groups ◽  
Rapid Loss ◽  
Binding Properties ◽  
Tyrosine Residues ◽  
Rat Muscle ◽  
Molar Excess

Reaction of rat muscle AMP deaminase with low molar excess of tetranitromethane results in a rapid loss of free thiol groups and a concomitant decrease in enzyme activity at high, but not at low, AMP concentration. This modification appears to be limited to the same non-essential thiol groups reactive towards specific reagents in non-denaturing conditions. On incubation with higher molar excess of tetranitromethane, a loss of enzyme activity is observed, which correlates with nitration of tyrosine residues. By amino acid analysis, approximately there tyrosine residues per subunit are estimated to be nitrated in the completely inactivated enzyme. The kinetic properties of the partially inactivated AMP deaminase reveal a negative co-operatively behaviour at approximately half saturation. This suggests that modification of tyrosine residues is also responsible for alteration of the binding properties of the hypothesized activating site of AMP deaminase.

scholarly journals Modulation of mammalian cardiac AMP deaminase by protein kinase C-mediated phosphorylation

1993 ◽  
Vol 291 (2) ◽  
pp. 523-527 ◽  
Author(s):  
J K Thakkar ◽  
D R Janero ◽  
C Yarwood ◽  
H M Sharif
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Rabbit Heart ◽  
Heart Tissue ◽  
Left Ventricular ◽  
Kinetic Properties ◽  
Amp Deaminase ◽  
Kinase C ◽  
Dependent Protein ◽  
Pkc Activation

Using AMP deaminase (AMP aminohydrolase; EC 3.5.4.6) purified from rabbit left-ventricular heart tissue, we report direct investigation of the potential for cardiac AMP deaminase activity to be regulated by kinase-mediated phosphorylation. Rabbit heart AMP deaminase served as a substrate for Ca2+/phospholipid-dependent protein kinase (protein kinase C; PKC) exclusively; no other mammalian protein kinase phosphorylated the enzyme. PKC-dependent AMP deaminase phosphorylation was rapid, linear with respect to time and the concentrations of PKC and AMP deaminase in the reaction, and inhibitable by staurosporine. Upon phosphorylation, the apparent Km of cardiac AMP deaminase decreased from 5.6 mM to 1.2 mM, without effect on the Vmax. Whether phosphorylated or not, rabbit heart AMP deaminase was inhibited by 1.0 mM GTP, which decreased the Vmax. by approximately 50% in each case. PKC-dependent phosphorylation of cardiac AMP deaminase did not alter the enzyme's allosterism toward millimolar ATP or ADP: both nucleotides at 1.0 mM concentration decreased the apparent Km to approximately 0.5 mM. Treatment of cardiac phospho-AMP deaminase with either the protein phosphatase calcineurin or alkaline phosphatase generated a dephosphorylated form which displayed molecular and kinetic properties identical with those of the originally isolated enzyme. These data raise the possibility that a phosphorylation-dephosphorylation mechanism may regulate flux through AMP deaminase in the heart under pathological conditions, such as myocardial ischaemia, characterized by PKC activation and adenylate depletion.

AMP-deaminase from goldfish white muscle: regulatory properties and redistribution under exposure to high environmental oxygen level

2008 ◽  
Vol 35 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Volodymyr I. Lushchak ◽  
Viktor V. Husak ◽  
Janet M. Storey ◽  
Kenneth B. Storey
Keyword(s):  
White Muscle ◽  
Oxygen Level ◽  
Amp Deaminase ◽  
Regulatory Properties
Sign in / Sign up

Export Citation Format

Share Document