DEHYDROGENASES DURING POSTEMBRYONIG DEVELOPMENT OF TRIBOLIUM CONFUSUM DUVAL (COLEOPTERA): I. MALATE DEHYDROGENASE AND MALIC ENZYME IN THE PARTICULATE AND SOLUBLE FRACTIONS

1967 ◽  
Vol 45 (9) ◽  
pp. 1393-1400 ◽  
Author(s):  
Sital Moorjani ◽  
André Lemonde
Keyword(s):  
Dehydrogenase Activity ◽  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Anaerobic Metabolism ◽  
Soluble Fraction ◽  
Larval Period ◽  
Tribolium Confusum ◽  
Sudden Increase ◽  
Kinetic Behavior ◽  
Soluble Fractions

Malate dehydrogenase and malic enzyme activities in the particulate (mitochondria) and soluble fraction have been determined in relation to the larval–pupal transformation of Tribolium confusum. The malate dehydrogenase activity in the soluble fraction follows a more or less inverse trend as compared with that in the particulate fraction. The malate dehydrogenase activity in the particulate and soluble fractions of the larva is attributed to different enzymes based on their electrophoretic mobility. A sudden increase in the activity of malate dehydrogenase in the soluble fraction at the end of the larval period is attributed to release of the enzyme from mitochondria by lysis. A further comparison of the larval particulate and pupal soluble malate dehydrogenase is made on the basis of their kinetic behavior. Malic enzyme is NADP-linked, although activity was also noted with NAD. The significance of the high activity of malic enzyme and malate dehydrogenase during pupation is discussed in relation to anaerobic metabolism.

Glyconeogenic and glycogenic enzymes in chronically active and normal skeletal muscle

1991 ◽  
Vol 71 (1) ◽  
pp. 182-191 ◽  
Author(s):  
R. J. Talmadge ◽  
H. Silverman
Keyword(s):  
Dehydrogenase Activity ◽  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Glycogen Phosphorylase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Fructose 1,6 Bisphosphatase ◽  
Fast Twitch ◽  
Whole Muscle

The chronically active (pseudomyotonic) gastrocnemius muscle in the C57B16J dy2J/dy2J mouse contains both elevated lactate and glycogen as well as fibers that have high amounts of glycogen and enhanced glyconeogenic activity. In the present study we analyze the activities of some key glyconeogenic enzymes to assess the causes of elevated muscle glycogen and to determine the pathway for glycogen synthesis from lactate. Glycogen synthase, malate dehydrogenase, phosphoenolpyruvate carboxykinase, and malic enzyme were all elevated in homogenates of the chronically active muscle. Activities of glycogen phosphorylase and fructose 1,6-bisphosphatase were decreased in whole muscle homogenates. Histochemistry demonstrated that the high-glycogen fibers were typically fast-twitch glycolytic fibers that had high glycogen synthase, glycogen phosphorylase, and malic enzyme activities. Malate dehydrogenase activity followed succinate dehydrogenase activity and did not correlate to high-glycogen fibers. Thus the high-glycogen fibers have an elevated enzymatic capacity for glycogen synthesis from lactate, and the pathway may involve use of the pyruvate kinase bypass enzymes.

scholarly journals Regulation of malate dehydrogenase activity by glutamate, citrate, alpha-ketoglutarate, and multienzyme interaction.

1988 ◽  
Vol 263 (22) ◽  
pp. 10687-10697 ◽  
Author(s):  
L A Fahien ◽  
E H Kmiotek ◽  
M J MacDonald ◽  
B Fibich ◽  
M Mandic
Keyword(s):  
Dehydrogenase Activity ◽  
Malate Dehydrogenase

The Utilisation of metabolic Water in Insects

1944 ◽  
Vol 35 (2) ◽  
pp. 127-139 ◽  
Author(s):  
G. Fraenkel ◽  
M. Blewett
Keyword(s):  
Body Weight ◽  
Water Content ◽  
Larval Development ◽  
Dry Weight ◽  
Larval Period ◽  
Tribolium Confusum ◽  
Ephestia Kuehniella ◽  
Final Size ◽  
Metabolic Water ◽  
Food Consumed

(1) Three insects,Tribolium confusum, Ephestia kuehniellaandDermestes vulpinus, have been grown at several humidities and the following factors have been determined: length of larval period; water content of food and of the freshly formed pupae; wet and dry weight of pupae and wet and dry weight of food consumed during larval development. The “net utilisation” of the food has been calculated as the ratio of dry weight of food eaten per larva to dry weight of pupa.(2) At lower humidities more food is eaten to produce a given unit of body weight. The length of the larval period increases and the weight of the pupae decreases.(3) More food is eaten at low humidities, because part of the food is utilised as water. As a consequence of this, the larva grows more slowly and its final size is smaller. It is shown forDermestesat 30 per cent. andEphestiaat 1 per cent. R.H. that less than 32·9 and 7·6 per cent. of the water in the pupae can be derived from water ingested with the food.

Analysis of isozymes related to energy metabolism of adult Tegillarca granosa

2007 ◽  
Vol 4 (2) ◽  
pp. 163-166
Author(s):  
Su Xiu-Rong ◽  
Lv Zhen-Ming ◽  
Li Tai-Wu ◽  
Liu Zhi-Ming ◽  
Paul K. Chien
Keyword(s):  
Energy Metabolism ◽  
Malic Enzyme ◽  
Energy Supply ◽  
Anaerobic Metabolism ◽  
Polyacrylamide Gel Electrophoresis ◽  
Pentose Phosphate ◽  
Considerable Proportion ◽  
Tegillarca Granosa ◽  
Phosphogluconate Dehydrogenase ◽  
Auxiliary Role

AbstractThe isozymes of 10 enzymes connected with energy metabolism in Tegillarca granosa were analysed by vertical polyacrylamide gel electrophoresis. Esterase and α-amylase are enzymes related to energy intake, their activities were high in the digestive gland. Malate dehydrogenase, malic enzyme, isocitrate dehydrogenase, succinate dehydrogenase, alcohol dehydrogenase, lactate dehydrogenase, 6-phosphogluconate dehydrogenase (G-6-PDH) and adenosine triphosphatase (ATPase) are enzymes related to energy metabolism. The main energy supply of T. granosa comes from aerobic respiration; anaerobic metabolism and the pentose phosphate pathway take an auxiliary role in energy metabolism. The high activity of G-6-PDH in T. granosa might mean a considerable proportion of carbohydrates metabolized through this pathway. This reaction could provide abundant NADP for metabolism in T. granosa. Compared with other shellfish, T. granosa had lower activity of ATPase, which might have some relationship with the amnicolous life and low motility of this animal.

IN VIVO SYNTHESIS AND BREAKDOWN OF DEOXYRIBONUCLEIC ACID IN TRIBOLIUM CONFUSUM DUVAL

1966 ◽  
Vol 44 (12) ◽  
pp. 1571-1575 ◽  
Author(s):  
K. D. Chaudhary ◽  
A. Lemonde
Keyword(s):  
Dna Synthesis ◽  
Growth Phase ◽  
Deoxyribonucleic Acid ◽  
Total Concentration ◽  
Larval Growth ◽  
Pupal Stage ◽  
Larval Period ◽  
Tribolium Confusum ◽  
In Vivo Synthesis

The in vivo synthesis of deoxyribonucleic acid (DNA), as shown by the rate of incorporation of14C-thymidine, has been investigated at different stages in the life cycle of Tribolium confusum. During the larval period, a close similarity is observed between the rate of DNA synthesis and the pattern of growth. The pupal stage, which is a non-growth phase, is characterized by a cessation of DNA synthesis. During the larval growth phase, although the 3-day-old larvae have the lowest and the 13-day-old have the highest rate of DNA synthesis, the rate of DNA degradation in the older larvae is almost twice as great as that of the younger larvae. These findings are consistent with the observed total concentration of DNA of the insect at these stages.

GLUCOSE AND RIBOSE OXIDATION BY PSEUDOMONAS FRAGI

1963 ◽  
Vol 41 (4) ◽  
pp. 1023-1034
Author(s):  
M. Leroux ◽  
H. L. A. Tarr
Keyword(s):  
Dehydrogenase Activity ◽  
Gluconic Acid ◽  
Soluble Fraction ◽  
Particulate Fraction ◽  
Pseudomonas Fragi ◽  
Dehydrogenase Enzyme ◽  
Specific Activities

The action of soluble and particulate fractions of sonically disrupted cells of Pseudomonas fragi on glucose and ribose was investigated. It was shown that ribose is oxidized by the particulate fraction to ribono-γ-lactone, but not further, thus verifying previous work. Evidence is presented in support of the fact that oxidation of both glucose and ribose is carried out by a single dehydrogenase enzyme, and that this enzyme is largely present in the particulate fraction. The soluble fraction possessed a lactonase enzyme which was purified slightly. This enzyme hydrolyzed glucono-δ-lactone but not glucono-γ-lactone. The washed particulate possessed no such lactonase activity. The soluble fraction possessed only about 4% of the dehydrogenase activity of the particulate fraction. Both the dehydrogenase and lactonase specific activities were similar when the organism was cultured in glucose or ribose-containing medium. Attempts to show that glucose was degraded by a phosphorolytic mechanism or that gluconic acid was degraded further failed. These findings are consistent with the fact that P. fragi oxidizes glucose to glucono-δ-lactone, and that this lactone is hydrolyzed to gluconic acid by a lactonase enzyme. No serious attempt was made to study the specificity of these enzymes, but it was observed that crude unwashed particulate fractions oxidized both galactose and mannose.

Fractionation of Rubber

1941 ◽  
Vol 14 (1) ◽  
pp. 1-14 ◽  
Author(s):  
George F. Bloomfield ◽  
Ernest Harold Farmer
Keyword(s):  
Molecular Weight ◽  
Soluble Fraction ◽  
Insoluble Fraction ◽  
The Other ◽  
Major Fraction ◽  
Low Concentrations ◽  
Fractional Dissolution ◽  
Judicious Choice ◽  
Hydrocarbon Molecules ◽  
Soluble Fractions

Abstract Latex rubber which has been purified to the point at which it contains an insignificant amount of nitrogen can be separated by fractional dissolution in a mixture of petroleum and acetone into a series of hydrocarbon fractions of decreasing solubility and increasing molecular magnitude. All these fractions except the highest are soluble in petroleum and in benzene. Crepe rubber, on the other hand, appears invariably to contain a small, most-soluble fraction of oxygenated rubber, and a small similar quite insoluble fraction of material of high molecular weight. Between these extremes the rubber can be divided into fractions of increasing molecular weight, although, up to the present, about 70 per cent of the total rubber has appeared in a single fraction. It may be possible later, by judicious choice of another pair of solvents, to resolve this major fraction into a series of subfractions. Kemp and Peters refer to the effect of polar nonsolvents in reducing the viscosity of rubber solutions and also in assisting to bring gel rubber into solution, phenomena to which the polar molecules conceivably contribute by countering the forces of association between the rubber molecules. The present series of fractionations was conducted throughout in the presence of a polar nonsolvent (acetone), and hence may be considered to approach towards a separation of true rubber molecules as distinct from molecular aggregates. It is found, however, that, whereas the more soluble fractions of acetone-extracted crepe rubber contain small proportions of nitrogen, the least soluble fractions contain substantial proportions. Any effect which the nitrogenous material may have in assisting to link together hydrocarbon molecules to which it is attached, i. e., in contributing to the high-molecular condition of a portion of natural rubber, remains at present uncertain in character. The fractions of rubber, and especially the higher ones, show a strong tendency to become insoluble when they have once been freed from the last traces of solvent. It seems doubtful whether the decreased solubility is due to oxygen as it would require to be effective at exceedingly low concentrations.

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