Effects of phenylalanine and alanine on the kinetics of bovine pyruvate kinase isoenzymes

Biochemistry ◽  
1975 ◽  
Vol 14 (18) ◽  
pp. 4041-4045 ◽  
Author(s):  
Janet M. Cardenas ◽  
J. Jeffrey Strandholm ◽  
Joan M. Miller
Keyword(s):  
Pyruvate Kinase ◽  
Pyruvate Kinase Isoenzymes ◽  
Kinetics Of

scholarly journals Characterization and Kinetics of Isoenzymes of Pyruvate Kinase from Developing Castor Bean Endosperm

1980 ◽  
Vol 65 (6) ◽  
pp. 1188-1193 ◽  
Author(s):  
Robert J. Ireland ◽  
Vincenzo De Luca ◽  
David T. Dennis
Keyword(s):  
Pyruvate Kinase ◽  
Castor Bean ◽  
Kinetics Of

scholarly journals Kinetics of a self-amplifying substrate cycle: ADP–ATP cycling assay

2000 ◽  
Vol 350 (1) ◽  
pp. 237-243 ◽  
Author(s):  
Edelmira VALERO ◽  
Ramón VARÓN ◽  
Francisco GARCÍA-CARMONA
Keyword(s):  
Lactate Dehydrogenase ◽  
Kinetic Study ◽  
Pyruvate Kinase ◽  
Adenylate Kinase ◽  
Reaction Medium ◽  
Spectrophotometric Assay ◽  
Background Signal ◽  
Cyclic System ◽  
Exponential Increase ◽  
Kinetics Of

A kinetic study of an ATP–ADP amplification cyclic system involving the enzymes adenylate kinase, pyruvate kinase and l-lactate dehydrogenase has been made. The stoichiometry of the cycle is 2:1, because two molecules of ADP are synthesized from one each of ATP and AMP, and one molecule of ADP is converted back into one of ATP at each turn of the cycle. This results in a continuous exponential increase in the concentrations of ATP and ADP in the reaction medium, according to the equations obtained. This is therefore a substrate cycle that amplifies itself, the cycling rate increasing continuously with time. The background signal of the reagent was reduced by using apyrase to degrade ATP and ADP in the reagent, permitting detection limits as low as 16pmol of ATP and/or ADP in a continuous spectrophotometric assay.

scholarly journals A kinetic study of rabbit muscle pyruvate kinase

1973 ◽  
Vol 131 (2) ◽  
pp. 223-236 ◽  
Author(s):  
S. Ainsworth ◽  
N. Macfarlane
Keyword(s):  
Reaction Mechanism ◽  
Kinetic Study ◽  
Pyruvate Kinase ◽  
Random Order ◽  
Experimental Results ◽  
Rabbit Muscle ◽  
Dead End ◽  
Inhibition Constants ◽  
Muscle Pyruvate Kinase ◽  
Kinetics Of

The paper reports a study of the kinetics of the reaction between phosphoenolpyruvate, ADP and Mg2+ catalysed by rabbit muscle pyruvate kinase. The experimental results indicate that the reaction mechanism is equilibrium random-order in type, that the substrates and products are phosphoenolpyruvate, ADP, Mg2+, pyruvate and MgATP, and that dead-end complexes, between pyruvate, ADP and Mg2+, form randomly and exist in equilibrium with themselves and other substrate complexes. Values were determined for the Michaelis, dissociation and inhibition constants of the reaction and are compared with values ascertained by previous workers.

Pyruvate kinase isoenzymes in human serum.

1984 ◽  
Vol 30 (1) ◽  
pp. 111-113
Author(s):  
J L Ngo ◽  
K N Garratt ◽  
P Eversole ◽  
R A Orlando ◽  
K H Ibsen
Keyword(s):  
Human Serum ◽  
Pyruvate Kinase ◽  
Electrophoretic Mobility ◽  
Kinase Activity ◽  
Published Data ◽  
Healthy Individuals ◽  
Progressive Decrease ◽  
Pyruvate Kinase Activity ◽  
Pyruvate Kinase Isoenzymes

Abstract Pyruvate kinase activity in serum from presumably healthy individuals is labile, but can be maintained for a week when samples are stored frozen. Contrary to published data our electrophoretic and isoelectrofocusing studies with fresh sera show the presence of both K and M isoenzymes; the latter predominates. In freezer-stored serum the putative M isoenzyme showed a progressive decrease in pl value as well as a decreased electrophoretic mobility.

Phosphorylation is switch of L-type pyruvate kinase allostery

2010 ◽  
Vol 5 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Ilona Faustova ◽  
Aleksei Kuznetsov ◽  
Erkki Juronen ◽  
Mart Loog ◽  
Jaak Järv
Keyword(s):  
Pyruvate Kinase ◽  
Hill Coefficient ◽  
Stoichiometric Ratio ◽  
Allosteric Enzyme ◽  
E Coli ◽  
Glycolysis Regulation ◽  
Regulatory Phosphorylation ◽  
Pyruvate Kinase Isoenzymes ◽  
Dependent Protein ◽  
The Hill

AbstractAmong four pyruvate kinase isoenzymes, M1, M2, R and L, only M1 is considered as a nonallosteric enzyme. However, here we show that the non-phosphorylated L-type pyruvate kinase (L-PK) is also a non-allosteric enzyme with respect to its substrate phosphoenolpyruvate (PEP). The allosteric catalytic properties of L-PK are switched on through phosphorylation by cAMP-dependent protein kinase. The non-phosphorylated enzyme was produced by expressing the rat L-PK in E. coli, as the bacterium does not have mammalian-type protein kinases. The resulting tetrameric protein was phosphorylated with a stoichiometric ratio of one mole of phosphate per one L-PK monomer. Activity of the phosphorylated enzyme was allosterically regulated by PEP with the Hill coefficient n=2.5. It was observed that allostery was engaged by phosphorylation of the first subunit in the tetrameric enzyme, while further phosphorylation only modulated this effect. The discovered switching between non-allosteric and allosteric forms of L-PK and the possibility of modulating the allostery by phosphorylation are important for understanding of the interrelationship between allostery and the regulatory phosphorylation in general, and may have implication for further analysis of glycolysis regulation in the liver.

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