Coenzyme dissociation, a possible determinant of short half-life of inducible enzymes in mammalian liver

Litwack, Gerald; Rosenfield, Sheila

doi:10.1016/0006-291x(73)90971-6

Cited by 77 publications

(9 citation statements)

References 27 publications

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“…An explanation for the differences between the in vitro ADH activities of late eggs from regular food and ethanol containing food found in this study may be that in the latter case an enzyme-substrate complex can be formed. It is well documented that such a complex is generally more stable than the free enzyme (Katunuma et a!., 1971a, b;Litwack and Rosenfield, 1973). If such a phenomenon occurs here this may explain the constancy of ADH activity on ethanol food and the decrease in activity on regular food.…”

Section: Ethanol Concentrat!on(% V/v)mentioning

confidence: 85%

Development of tolerance to ethanol in relation to the alcohol dehydrogenase locus in Drosophila melanogaster 1. Adult and egg-to-adult survival in relation to ADH activity

Kerver

Delden

1985

Heredity

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Strains of Drosophila melanogaster homozygous either for the AdhF or the Adhs allele, were kept on food supplemented with ethanol. After 90 generations these strains (FFE and SSE) were tested for tolerance to ethanol and compared with control strains (FFN and SSN) from regular food. The E strains showed increased tolerance to ethanol, both in the adult and in the juvenile life stages. In the adults the increase in tolerance was not accompanied by an increase in ADH activity. In the juvenile life stages there were significant differences in ADH activity between the E and N strains, both on regular food and on food containing ethanol. However, ADH activity was not the only factor involved in the increased tolerance to ethanol.The Adh genotype of the mother was of paramount importance to egg-to-adult survival because of a maternal effect on ethanol tolerance in the eggs and first instar larvae. Furthermore developmental times of the E strains were longer than those of the corresponding N strains. It is concluded that the adaptation to ethanol-containing food was not realised in the same way in the FFE and SSE strains.

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Section: Ethanol Concentrat!on(% V/v)mentioning

confidence: 85%

Development of tolerance to ethanol in relation to the alcohol dehydrogenase locus in Drosophila melanogaster 1. Adult and egg-to-adult survival in relation to ADH activity

Kerver

Delden

1985

Heredity

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“…A second possible explanation is that the 2-propanol induced isozyme con version has increased the vivo stability of the alcohol dehydrogenase present in the treated flies. This would be consistent with a number of reports that suggest the presence of substrate and/or coenzyme increases the stability of that enzyme (Katunuma et al, 1971a,b;Litwack and Rosenfield, 1973;Goldberg and Dice, 1974),…”

Section: Time (Hrs)supporting

confidence: 92%

“…The amino acid substitution is found in the NAD binding domain of the protein sug gesting it may have an effect on the association of the ADH-UF protein with its cofactor. The results presented in section C2 as well as the results of other authors (i.e., Litwack and Rosenfield, 1973) show that the association of an enzyme with its cofactor may drastically affect the enzyme's stability. Therefore, the nature of this association for the ADH-UF protein may account for its in vivo stability.…”

Section: Discussionsupporting

confidence: 65%

“…After exposure to 2-propanol, there is a dramatic increase in the ADH-1 form of the enzyme, which is known to be associated with two molecules of an NADcarbonyl complex (Schwartz et al, 1979). It is well-documented that an enzyme-substrate or enzyme-coenzyme complex is generally more stable than its apo-enzyme (Katunuma et al, 1971a,b;Litwack and Rosenfield, 1973) and it is believed that just such a phenomenon may be occurring here.…”

Section: Discussionmentioning

confidence: 84%

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Molecular basis of alcohol adaptation in Drosophilia melanogaster

Anderson

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“…This does not exclude the possibility that inactivation may involve the scission of a large peptide residue which is precipitable with trichloroacetic acid, or of a small non-precipitable peptide not containing the radioactive label. It is also possible that some change in the spatial configuration of the active site may occur owing to interactions with a variety of ligands, including membrane proteins or lipids, cofactors, metabolic intermediates, and other proteins (Schimke, 1975;Litwack and Rosenfield, 1973). Enzymes capable of inactivating NAD + dependent enzymes have been reported in rat liver (Katunuma et al, 1971), and similar agents may occur in rabbit leucocytes.…”

mentioning

confidence: 99%

Inactivation in Vitro of Lactate Dehydrogenase-5 in Blood

Qureshi

Wilkinson

1977

Ann Clin Biochem

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During incubation with rabbit blood in vitro rabbit-muscle lactate dehydrogenase-S 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. MATERIALS AND METHODSPurified rabbit-muscle lactate dehydrogenase-5 (LD-5) was obtained from the Boehringer Corporation (London) Ltd., London.the results of experiments designed to test this hypothesis are described in this communication.Rabbit-muscle lactate dehydrogenase-5 (LD-5) was selected for study since its relatively short life in vivo suggests that in vitro experiments could be completed within 10-12 h. This short period would minimise complications due to possible contamination. Another advantage of choosing this isoenzyme is the presence of no more than traces in the erythrocytes, so that leakage from the red cells has little effect on the plasma LD-5 activity.Lactate dehydrogenase activity was determined by the reduction of pyruvate in the presence of NADH (Wroblewski and LaDue, 1955). The reaction was carried out at 25 ± 0.1 DC in the cuvette compartment of a Unicam SP 1800 recording spectrophotometer. The change in absorbance at 340 nrn was recorded over a period of 5 min.The activity of LD-5 in the presence of LD-I was determined by the incorporation of oxalate (0.2 rnmol/l) into the reaction mixture (Emerson et al., 1964). Oxalate non-competitively inhibits the reduction of pyruvate and also strongly inhibits the fast moving isoenzyrnes LD-I and LD-2 while it exerts little effect on the activity of LD-5.The diagnostic value of the elevation of plasma enzyme activities in acute diseases of the liver, heart, and other organs is well established, but little is known of the mechanism whereby enzyme activities return to normal during recovery. Many clinical (Clubb et al., 1965;Wilkinson, 1970; Sobel et al., J972) and experimental studies Wakim and Fleisher, 1963;Boyd, 1967) have demonstrated that the disappearance rates of circulating enzymes are relatively constant in a given species, but apart from excluding elimination in the urine or bile as a mechanism for the removal of enzymes from the plasma (Strandjord et al., 1959;Rosalki and Wilkinson, 1959) the results of earlier work have been inconclusive.Recently, however, we reported that after the intravenous injection of 125I-labelled lactate dehydrogenase-S (LD-5) in the rabbit a distributional phase, in which the plasma radioactivity and plasma Determination of enzyme activity catalytic activity disappeared exponentially at comparable fast rates, was followed by a phase during which the plasma catalytic activity disappeared at a significantly faster rate (Kd = 0.19 ± S.D.0.02 h-1) than the plasma radioactivity (K« = 0.057 ± S.D. 0.01 I h-1) (P < 0.001) . This finding was interpreted as indicati...

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Coenzyme dissociation, a possible determinant of short half-life of inducible enzymes in mammalian liver

Cited by 77 publications

References 27 publications

Development of tolerance to ethanol in relation to the alcohol dehydrogenase locus in Drosophila melanogaster 1. Adult and egg-to-adult survival in relation to ADH activity

Development of tolerance to ethanol in relation to the alcohol dehydrogenase locus in Drosophila melanogaster 1. Adult and egg-to-adult survival in relation to ADH activity

Molecular basis of alcohol adaptation in Drosophilia melanogaster

Inactivation in Vitro of Lactate Dehydrogenase-5 in Blood

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