Studies on Liver Alcohol Dehydrogenase. III. The Influence of pH and Some Anions on the Reaction Velocity Constants.

Theorell, Hugo; Nygaard, Agnar P.; Bonnichsen, Roger; Virtanen, Artturi I.

doi:10.3891/acta.chem.scand.09-1148

Cited by 167 publications

(30 citation statements)

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“…In 1955, Theorell and coworkers (12) first reported that LADH contained 2 gram atoms of zinc per mole, a value later confirmed in our laboratory (13) and consistent with the demonstration of two active sites on the basis of coenzyme binding (14,15). However, during the past 15 years, methods for purification of the enzyme and estimation of its specific activity and molecular weight have been revised repeatedly, re sulting in uncertainties concerning the molar stoichiometry of protein and metal.…”

Section: Alcohol Dehydrogenase From Equine Liversupporting

confidence: 66%

Structure and Function of Metalloenzymes

Ulmer

Vallée

1971

Advances in Chemistry

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In metalloenzymes, metals which affect function directly by participation in catalysis appear to have ligand sites which differ markedly from those of metals which influence function indirectly through modulation of protein structure. Thus, in both E. coli alkaline phosphatase and equine liver alcohol dehydrogenase, metals positioned at the active site interact selectively with chelating agents, undergo isotope exchange, and display distinctive physical chemical characteristics. Such active site metals may have an irregular geometry which facilitates their catalytic role. In contrast, nonactive site metals exhibit physical properties more like those of simple, bidentate model complexes; they frequently appear to stabilize structure or influence subunit interactions as shown by their effects on sedimentation or hydrogen exchange rates of proteins. Such "structural" metals may function importantly in control mechanisms for biochemical reactions.Touring the past two decades, considerable progress in understanding **** the role of metals in biological processes has resulted from the discovery and purification of a large number of metalloproteins and from efforts to ascertain their function-e.g., in catalysis, electron transport, or gas exchange (I). Studies of the physical chemical properties of this group of proteins have been of particular interest because of the presence of the inorganic moiety. In principle, metals should be excellent labels of the protein sites to which they bind owing to the distinctive physical properties of metal complexes with common ligands-e.g., color, in the case of copper, cobalt, or iron salts. Hence, one might have hoped that the basic characteristics of the metal, known from studies of inorganic complexes, would be preserved in biological systems and aid identification of the ligand groups and their properties at protein loci of special

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Section: Alcohol Dehydrogenase From Equine Liversupporting

confidence: 66%

Structure and Function of Metalloenzymes

Ulmer

Vallée

1971

Advances in Chemistry

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“…Although the Km value of ADH for glyceraldehyde (33) is much greater than for acetaldehyde (38), the concentration of the latter substance is probably extremely low (39). The concentrations of the aldehydes in the liver cells during these conditions are, however, not known.…”

Section: Resultsmentioning

confidence: 92%

The Mechanism of the Fructose Effect on the Ethanol Metabolism of the Human Liver*

Tygstrup¹,

Winkler²,

Lundquist³

1965

J. Clin. Invest.

141

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Ethanol is normally metabolized at a constant rate by the liver of man and animals. Attempts to change this rate have included treatment with metabolically active substances such as glucose, pyruvate, amino acids, dinitrophenol, insulin, and thyroid hormone. In some cases an increase has been observed, but usually only a very small one. The only exception so far discovered is the effect of fructose, first demonstrated by Stuhlfauth and Neumaier (1). This was confirmed by Pletscher, Bernstein, and Staub (2), who found an average increase in the elimination rate of ethanol of 80% in dogs receiving 1 to 2 g of fructose per kg per hour, and about 70% in human subjects who had fructose infused intravenously in comparable quantities (3). Oral ingestion of fructose in man gave the same result (4). Smaller or no effects have also been reported (5, 6), but in these cases the amount of fructose given was probably -insufficient.Several explanations of the phenomenon (which we shall refer to as the "fructose effect") have been offered, but since none of them were supported by direct experimental evidence, a detailed, quantitative investigation of the problem appeared desirable. Furthermore, it was of interest to study the circulatory and metabolic reactions of the liver during accelerated ethanol metabolism, as previous studies have shown that under normal con-

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“…Also. it is reporte(l that anions influence the association an-I (lissociation velocity constants of DPN and DPNH with alcohol dehydlrogenase (23). The influelnce of salts on the activity of malic dehydrogenase night be explained (20) of the influence of salts on the activity of glucose-6-phosphate dehydrogenase.…”

Section: Discussionmentioning

confidence: 99%

“…Other compounds such as KCI, NaCl, K.S04, or Na.,HAsO4 replaced phosphate in systems buffered with Tris. Theorell et al (23) reported that chloride, bromide, sulfate, nitrate, formate, and acetate markedly reduced the activity of the alcohol dehydrogenase system. Walaas and Walaas (27) found that certain anions inhibited the activity of D-amino acid oxidase from pig kidney.…”

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confidence: 99%

Influence of Salts on Activity of Malic Dehydrogenase from Spinach Leaves

Hiatt

Evans

1960

Plant Physiol.

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It is well established (10,18,19) that the respiratory rates of plant tissues containing low concentrations of salts are markedly stimulated by adding to the bathing medium any one of a variety of salts. In view of this fact and of the limited information available on the biochemical role of certain essential mineral ions in metabolism it seems that any detailed information concerning the influence of the ionic environnient onl the activities of important respiratory or other plant enzymes may be of considerable physiological interest.There is considerable information in the literature indicating effects of the ionic environment on the activity of both particulate and soluble enzyme preparations. It has been reported (13) that inorganic salts of both univalent and divalent cations markedly stimulatedl the activity of particulate cytochrome oxidase. Honda et al (6) have shown that the rate of oxidation of reduced diphosphopyridine nucleotide (DPNH) catalyzed by Nwashed mitochondria from beet root (Beta vulgaris L.) was increased by adding certain salts to the assay medium. The activity of glucose-6-phosphate dehydrogenase was reported to be increased as nmuch as six-fold by low concentrations of certain anions (20). The ionic environment markedly affected the Michaelis constant (K,,) of this enzynie with respect to both glucose-6-phosphate and TPN. Massey (12) reported that sulfate, selenate, arsenite, citrate, borate, phosphate, and arsenate, in increasing order of effectiveness, activated salt-free fumarase and altered the pH of optimal activity while chloridle, bromide, thiocyanate, and iodide in increasing or(ler of effectiveness, inhibited the activity of this enzyme. The extent of inhibition was markedlly dependent on pH. Zelitch (29) has reported that the rate of reduction of hydroxypyruvate as catalyzed by crystalline glyoxylic acid reductase was markedly increased by various anions and that the magnitude of activation was not the same at different pH levels. Eichel (5) reported that DPNH oxidase activity of cell-free homogenates of Tetrahvmnena pvriform,wis was increased two-to three-fold when phosphate was used with tris(hydroxymethyl)aminomethane (Tris) buffer. Other compounds such as KCI, NaCl, K.S04, or Na.,HAsO4 replaced phosphate in systems buffered with Tris.

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Studies on Liver Alcohol Dehydrogenase. III. The Influence of pH and Some Anions on the Reaction Velocity Constants.

Cited by 167 publications

References 0 publications

Structure and Function of Metalloenzymes

Structure and Function of Metalloenzymes

The Mechanism of the Fructose Effect on the Ethanol Metabolism of the Human Liver*

Influence of Salts on Activity of Malic Dehydrogenase from Spinach Leaves

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