scholarly journals Evaluation of equilibrium constants for the interaction of lactate dehydrogenase isoenzymes with reduced nicotinamide-adenine dinucleotide by affinity chromatography

1975 ◽  
Vol 151 (3) ◽  
pp. 631-636 ◽  
Author(s):  
R I Brinkworth ◽  
C J Masters ◽  
D J Winzor
Keyword(s):  
Lactate Dehydrogenase ◽  
Affinity Chromatography ◽  
Equilibrium Constants ◽  
Mouse Tissue ◽  
Rabbit Muscle ◽  
Muscle Lactate ◽  
Sodium Phosphate Buffer ◽  
A Value ◽  
Series Of Experiments ◽  
Reduced Nicotinamide Adenine Dinucleotide

Rabbit muscle lactate dehydrogenase was subjected to frontal affinity chromatography on Sepharose-oxamate in the presence of various concentrations of NADH and sodium phosphate buffer (0.05 M, pH 6.8) containing 0.5 M-NaCl. Quantitative interpretation of the results yields an intrinsic association constant of 9.0 × 104M−1 for the interaction of enzyme with NADH at 5°C, a value that is confirmed by equilibrium-binding measurements. In a second series of experiments, zonal affinity chromatography of a mouse tissue extract under the same conditions was used to evaluate assoication constants of the order 2 × 105M−1, 3 × 105M−1, 4 × 105M−1, 7 × 105M−1 and 2 × 106M−1 for the interaction of NADH with the M4, M3H, M2H2, MH3 and H4 isoenzymes respectively of lactate dehydrogenase.

Flow kinetics of lactate dehydrogenase chemically attached to nylon tubing

1978 ◽  
Vol 56 (8) ◽  
pp. 774-779 ◽  
Author(s):  
N. J. Daka ◽  
K. J. Laidler
Keyword(s):  
Lactate Dehydrogenase ◽  
Flow Rate ◽  
Rabbit Muscle ◽  
Modified Technique ◽  
Muscle Lactate ◽  
Flow Rates ◽  
Diffusion Controlled ◽  
Michaelis Constants ◽  
Reduced Nicotinamide Adenine Dinucleotide ◽  
Nylon Tubing

Rabbit muscle lactate dehydrogenase (EC 1.1.1.27) was attached covalently to the inner surface of nylon tubing; a modified technique, involving benzidine and glutaraldehyde, was used, and the resulting immobilized enzyme showed no loss of activity over a period of several months. An experimental study was made of the flow kinetics for the reaction between pyruvate and reduced nicotinamide adenine dinucleotide in two limiting cases, one substrate in excess and the concentration of the other one varied. A range of flow rates and temperatures was covered. The results were analyzed in various ways on the basis of the Kobayashi–Laidler treatment of flow systems. It was concluded that the kinetics are largely diffusion-controlled, especially at the lower substrate concentrations and flow rates. The values of the apparent Michaelis constants vary with flow rate vf, being linear in vf−1/3, and the values extrapolated to infinite flow rate (vf−1/3 = 0) approach the values for the enzyme in free solution. Analysis of the rates led to activation energies for the diffusion of the two substrates.

scholarly journals Thermodynamic studies of the activation of rabbit muscle lactate dehydrogenase by phosphate

1983 ◽  
Vol 215 (3) ◽  
pp. 685-691 ◽  
Author(s):  
L D Ward ◽  
D J Winzor
Keyword(s):  
Lactate Dehydrogenase ◽  
Equilibrium Constant ◽  
Ternary Complex ◽  
Competitive Inhibition ◽  
Equilibrium Constants ◽  
Kinetic Studies ◽  
Phosphate Concentration ◽  
Rabbit Muscle ◽  
Muscle Lactate ◽  
Coenzyme Binding

In an attempt to trace the source of phosphate activation of the enzyme-catalysed pyruvate-lactate interconversion by rabbit muscle lactate dehydrogenase, equilibrium constants were measured to examine the effects of phosphate on interactions pertinent to the enzymic process. Frontal gel-chromatographic studies of the binding of NADH to the enzyme established that the intrinsic association constant is doubled in the presence of 50 mM-phosphate in the buffer (pH 7.4, I0.15). From kinetic studies of the competition between NAD+ and NADH for the coenzyme-binding sites of the enzyme it is concluded that the binding of oxidized nicotinamide nucleotide is also doubled in the presence of 50 mM-phosphate. Competitive-inhibition studies and fluorescence-quenching measurements indicated the lack of a phosphate effect on ternary-complex formation between enzyme-NADH complex and oxamate, a substrate analogue of pyruvate. The equilibrium constant for the interaction between enzyme-NAD+ complex and oxalate, an analogue of lactate, was also shown, by difference spectroscopy, to be insensitive to phosphate concentration. Provided that the effects observed with the substrate analogues mimic those operative in the kinetic situation, the equilibrium constant governing the isomerization of ternary complex is also independent of phosphate concentration. It is concluded that enhanced coenzyme binding is the source of phosphate activation of the rabbit muscle lactate dehydrogenase system.

scholarly journals Kinetic Studies of Rabbit Muscle Lactate Dehydrogenase

1962 ◽  
Vol 237 (5) ◽  
pp. 1668-1675
Author(s):  
Virginia Zewe ◽  
Herbert J. Fromm
Keyword(s):  
Lactate Dehydrogenase ◽  
Kinetic Studies ◽  
Rabbit Muscle ◽  
Muscle Lactate

Interactions of Kepone with rabbit muscle lactate dehydrogenase

1978 ◽  
Vol 26 (1) ◽  
pp. 130-133 ◽  
Author(s):  
Bruce M. Anderson ◽  
Susan T. Kohler ◽  
Roderick W. Young
Keyword(s):  
Lactate Dehydrogenase ◽  
Rabbit Muscle ◽  
Muscle Lactate

scholarly journals Affinity chromatography of lactate dehydrogenase on immobilized nucleotides

1973 ◽  
Vol 133 (3) ◽  
pp. 515-520 ◽  
Author(s):  
C. R. Lowe ◽  
P. D. G. Dean
Keyword(s):  
Skeletal Muscle ◽  
Lactate Dehydrogenase ◽  
Affinity Chromatography ◽  
Heart Muscle ◽  
Adenine Nucleotides ◽  
Free Solution ◽  
Muscle Lactate ◽  
Effects Of Ph ◽  
Influence Of Substrate ◽  
Lactate Dehydrogenase Isoenzymes

The interaction of two isoenzymes of lactate dehydrogenase from pig heart muscle (H4) and rabbit skeletal muscle (M4), with immobilized nucleotides was examined: the effects of pH and temperature on the binding of lactate dehydrogenase were studied with immobilized NAD+ matrices. The influence of substrate, product and sulphite on the binding of heart muscle lactate dehydrogenase to immobilized NAD+ was investigated. The interaction of both lactate dehydrogenase isoenzymes with immobilized pyridine and adenine nucleotides and their derivatives were measured. The effects of these parameters on the interaction of lactate dehydrogenase with immobilized nucleotides were correlated with the known kinetic and molecular properties of the enzymes in free solution.

Inactivation in Vitro of Lactate Dehydrogenase-5 in Blood

1977 ◽  
Vol 14 (1-6) ◽  
pp. 48-52 ◽  
Author(s):  
A. R. Qureshi ◽  
J. H. Wilkinson
Keyword(s):  
Enzyme Activity ◽  
Lactate Dehydrogenase ◽  
Whole Blood ◽  
Rabbit Muscle ◽  
Muscle Lactate ◽  
Rabbit Blood

During incubation with rabbit blood in vitro rabbit-muscle lactate dehydrogenase-5 was inactivated at a rate similar to that observed in vivo. By contrast plasma and plasma containing erythrocytes had no effect on the enzyme activity, but plasma containing leucocytes inactivated the enzyme at the same rate as whole blood. The results obtained support the concept that intravascular inactivation accounts for the disappearance of enzymes from the circulation.

scholarly journals The mechanism of adduct formation between NAD+ and pyruvate bound to pig heart lactate dehydrogenase

1979 ◽  
Vol 177 (3) ◽  
pp. 951-957 ◽  
Author(s):  
D C Wilton
Keyword(s):  
Lactate Dehydrogenase ◽  
Dissociation Constant ◽  
Active Site ◽  
Adduct Formation ◽  
Rabbit Muscle ◽  
Muscle Lactate

1. The rate of adduct formation between NAD+ and enol-pyruvate at the active site of lactate dehydrogenase is determined by the rate of enolization of pyruvate in solution. 2. The proportion of enol-pyruvate solutions is less than 0.01%. 3. The overall dissociation constant of adduct formation is less than 5 × 10(-8) M for pig heart lactate dehydrogenase at pH 7.0. 4. The unusual kinetics for adduct formation previously observed in the case of rabbit muscle lactate dehydrogenase [Griffin & Criddle (1970) Biochemistry 9, 1195–1205] may be attributed to the concentration of enol-pyruvate in solution being considerably less than the concentration of enzyme.

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