scholarly journals Nicotinamide-adenine dinucleotide-linked “malic” enzyme in flight muscle of the tse-tse fly (Glossina) and other insects

1976 ◽  
Vol 160 (2) ◽  
pp. 253-262 ◽  
Author(s):  
J B Hoek ◽  
D J Pearson ◽  
N K Olembo
Keyword(s):  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Flight Muscle ◽  
Intracellular Localization ◽  
Deae Cellulose ◽  
Partial Purification ◽  
Decarboxylase Activity ◽  
Matrix Space ◽  
Oxaloacetate Decarboxylase ◽  
Ph Optimum

1. A high activity of NAD-linked ‘malic’ enzyme was found in homogenates of flight muscle of different species of tse-tse fly (Glossina). The activity was the same as, or higher than, that of malate dehydrogenase and more than 20-fold that of NADP-linked ‘malic’ enzyme. A similar enzyme was found in the flight muscle of all other insects investigated, but at much lower activities. 2. ACa2+-stimulated oxaloacetate decarboxylase activity was present in all insect flight-muscle preparations investigated, in constant proportion to the NAD-linked ‘malic’ enzyme. 3. A partial purification of the NAD-linked ‘malic’ enzyme from Glossina was effected by DEAE-cellulose chromatography, which separated the enzyme from malate dehydrogenase and NADP-linked ‘malic’ enzyme, but not from oxaloacetate decarboxylase. 4. The intracellular localization of the NAD-linked ‘malic’ enzyme was predominantly mitochondrial; latency studies suggested a localization in the mitochondrial matrix space. 5. Studies on the partially purified enzyme demonstrated that it had a pH optimum between 7.6 and 7.9. It required Mg2+ or Mn2+ for activity; Ca2+ was not effective. The maximum rate was the same with either cation, but the concentration of Mn2+ required was 100 times less than that of Mg2+. Acitivity with NADP was only 1-3% of that with NAD, unless very high (greater than 10mM) concentrations of Mn2+ were present. 6. It is suggested that the NAD-linked ‘malic’ enzyme functions in the proline-oxidation pathway predominant in tse-tse fly flight muscle.

Guanosine 3’:5’-Cyclic Monophosphate -Dependent Particulate Protein Kinase Activity from Yeast (Saccharomyces cerevisiae)

1999 ◽  
Vol 54 (1-2) ◽  
pp. 84-93 ◽  
Author(s):  
Hans Eckstein ◽  
Birgit Flügge
Keyword(s):  
Protein Kinase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Temperature Tolerance ◽  
Maximum Activity ◽  
Partial Purification ◽  
Protein Kinase Activity ◽  
Ph Optimum ◽  
Yeast Saccharomyces Cerevisiae ◽  
High Concentrations

Continuing our studies on cGMP in growing yeast we detected a particulate cGMPdependent protein kinase (Pk-G), which was solubilized by detergents and NaCl. It achieves maximum activity at 25 °C and pH = 6.8, high concentrations of substrate proteins or cGMP produce saturation. Casein and histones are appropriate substrates, phosphatase-pretreated histone H-2a provokes outstandingly high activity. Pk-G differs from cAMP-dependent protein kinase (Pk-A) with respect to pH optimum, temperature tolerance above 50 °C, and stability. Partial purification is achieved by chromatography with DEAE-cellulose, Sepharose, and cGMP-substituted Sepharose. The latter step also markedly removes Pk-A. At least three proteins with Pk-G-activity and high cGMP-affinity are separated by polyacrylamide-gel-electrophoresis. Their apparent molecular masses, as deduced from comigrating marker proteins, differ considerably from those of other Pk-G’s, but also of Pk-A’s

scholarly journals Properties and regulation of leaf nicotinamide–adenine dinucleotide phosphate–malate dehydrogenase and ‘malic’ enzyme in plants with the C4-dicarboxylic acid pathway of photosynthesis

1970 ◽  
Vol 119 (2) ◽  
pp. 273-280 ◽  
Author(s):  
Hilary S. Johnson ◽  
M. D. Hatch
Keyword(s):  
Dicarboxylic Acid ◽  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Maximum Velocity ◽  
Enzyme Reaction ◽  
Reverse Direction ◽  
Leaf Extracts ◽  
Ph Optimum ◽  
Acid Pathway

1. NADP–malate dehydrogenase and `malic' enzyme in maize leaf extracts were separated from NAD–malate dehydrogenase and their properties were examined. 2. The NADP–malate dehydrogenase was nicotinamide nucleotide-specific but otherwise catalysed a reaction comparable with that with the NAD-specific enzyme. By contrast with the latter enzyme, a thiol was absolutely essential for maintaining the activity of the NADP–malate dehydrogenase, and the initial velocity in the direction of malate formation, relative to the reverse direction, was faster. 3. For the `malic' enzyme reaction the Km for malate was dependent on pH and the pH optimum varied with the malate concentration. At their respective optimum concentrations the maximum velocity for this enzyme was higher with Mg2+ than with Mn2+. 4. The NADP–malate dehydrogenase in green leaves was rapidly inactivated in the dark and was reactivated when plants were illuminated. Reactivation of the enzyme extracted from darkened leaves was achieved simply by adding a thiol compound. 5. The activity of both enzymes was low in etiolated leaves of maize plants grown in the dark but increased 10–20-fold, together with chlorophyll, when leaves were illuminated. 6. The activity of these enzymes in different species with the C4-dicarboxylic acid pathway was compared and their possible role in photosynthesis was considered.

scholarly journals Partial purification and properties of nicotinamide adenine dinucleotide synthetase from human erythrocytes: evidence that enzyme activity is a sensitive indicator of lead exposure

Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1576-1582
Author(s):  
CR Zerez ◽  
MD Wong ◽  
KR Tanaka
Keyword(s):  
Lead Exposure ◽  
Nicotinamide Adenine Dinucleotide ◽  
Deae Cellulose ◽  
Human Erythrocytes ◽  
Sensitive Indicator ◽  
Nicotinamide Adenine ◽  
Partial Purification ◽  
Synthetase Activity ◽  
Ph Optimum ◽  
Nad Synthetase

We have examined properties of nicotinamide adenine dinucleotide (NAD) synthetase from human erythrocytes. The enzyme was found to be cold labile and extremely unstable in crude hemolysate, with complete loss of activity occurring after 24 hours at 4 degrees C. However, maintenance of crude hemolysate at 20 to 25 degrees C in the presence of EDTA and KCl increased NAD synthetase stability substantially (half- life = 10 days). Using these conditions, NAD synthetase was purified 3,100-fold with a 29% yield using DEAE-cellulose column chromatography, ammonium sulfate fractionation, and dialysis. The apparent Michaelis- Menten constants for nicotinic acid adenine dinucleotide (NAAD), adenosine triphosphate, Mg2+, glutamine, and K+ were 0.108, 0.154, 1.36, 2.17, and 8.32 mmol/L, respectively. The pH optimum ranged between 6.8 and 7.4, and the molecular weight was estimated to be 483 +/- 5 Kd. The enzyme was markedly inhibited by Pb2+ and Zn2+, with concentrations necessary for 50% inhibition of activity of 1.3 and 2.0 mumol/L, respectively. The incubation of intact red blood cells with lead followed by rigorous washing to remove lead abolished nearly all NAD synthetase activity. In contrast, glucose-6-phosphate dehydrogenase activity, which is not sensitive to lead, was unaffected, whereas pyrimidine 5′-nucleotidase activity, which is sensitive to lead, was decreased 30% to 50% under these conditions. More importantly, patients with lead overburden (34 to 72 micrograms Pb2+/dL blood) all had markedly decreased NAD synthetase activity. These data together with other results suggest that erythrocyte NAD synthetase activity is a sensitive indicator of lead exposure in humans.

scholarly journals Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum

2006 ◽  
Vol 18 (2) ◽  
pp. 291-298 ◽  
Author(s):  
D. R. Chhetri ◽  
A. K. Mukherjee ◽  
J. Adhikari
Keyword(s):  
De Novo ◽  
Deae Cellulose ◽  
Normal Growth ◽  
Apparent Molecular Weight ◽  
Life Forms ◽  
Partial Purification ◽  
Ph Optimum ◽  
Inositol 1 ◽  
Isolation And Characterization ◽  
Phosphate Synthase

Myo-inositol is involved in normal growth and development of all living organisms and L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) is responsible for its de novo synthesis. This enzyme has been reported for a number of life forms including plants, animals and bacteria. In the present study free myo-inositol has been detected in the common pteridophytes found in the Darjeeling Himalayas and the enzyme, L-myo-inositol-1-phosphate synthase has been partially purified from Diplopterygium glaucum (Thunb.) Nakai. A crude homogenate from the reproductive pinnules of D. glaucum was subjected to streptomycin sulphate precipitation and 0-70% ammonium sulphate fractionation followed by successive chromatography through DEAE-cellulose, Hexylagarose and BioGel A-0.5m columns. This resulted in a partial purification of the enzyme of about 81-fold with 13.5% recovery. The pteridophytic MIPS specifically utilized D-glucose-6-phosphte and NAD+ as its substrate and co-factor, respectively. It shows a pH optimum between 7.0 and 7.5 while the temperature maximum was 30 °C. The enzyme activity was stimulated by NH4+, slightly inhibited by Na+, Ba2+ and Cd2+, and strongly inhibited by Li+, Zn2+ and Hg2+. EDTA, pCMB and some substrate isomers like glucose-1-phosphate, fructose-6-phosphte and galactose-6-phosphate were inhibitory to the enzyme. The apparent molecular weight of the native D. glaucum MIPS was determined to be approximately 171 kDa.

scholarly journals The partial purification and characterization of cytosol alcohol dehydrogenase from Astasia

1974 ◽  
Vol 141 (2) ◽  
pp. 469-475 ◽  
Author(s):  
Rolf Morosoli ◽  
Nicole Bégin-Heick
Keyword(s):  
Molecular Weight ◽  
Alcohol Dehydrogenase ◽  
Polyacrylamide Gel Electrophoresis ◽  
Deae Cellulose ◽  
Total Activity ◽  
Growth Conditions ◽  
Partial Purification ◽  
Heat Inactivation ◽  
Kinetic Properties ◽  
Ph Optimum

1. The cytosol alcohol dehydrogenase (alcohol–NAD oxidoreductase, EC 1.1.1.1) of Astasia longa was partially purified and characterized from cells grown in the presence of air+CO2 (95:5) or of O2+CO2 (95:5). 2. Under both these growth conditions, the cells contained a fraction, ADHII, which was characterized by its electrophoretic properties, by a high degree of resistance to heat inactivation, by a sharp pH optimum at 8.2 and by its kinetic properties. The estimated molecular weight of this fraction was approx. 150000, which is similar to that of yeast alcohol dehydrogenase. 3. Cells grown in air+CO2 (95:5) contain another fraction, ADHI, which can be further separated into two subfractions by polyacrylamide-gel electrophoresis and by DEAE-cellulose chromatography. This was termed fraction ‘ADHI-air’. 4. In addition to fraction ADHII, cells grown in the presence of O2 have a twofold increase in fraction ADHI-air activity as well as two new fractions that could not be demonstrated in air-grown cells. These new fractions which we have called fraction ‘ADHI-O2’, account for about 10% of the total activity. 5. The ADHI fractions (air) and (O2) have similar broad pH–activity curves and similar kinetic properties, both having a lower Km for ethanol and NAD than fraction ADHII. However, they differ from each other with respect to their activity with various substrates. The estimated molecular weight of these two ADHI fractions and their chromatographic behaviour on hydroxyapatite and on DEAE-cellulose also distinguish them.

scholarly journals Partial purification and properties of nicotinamide adenine dinucleotide synthetase from human erythrocytes: evidence that enzyme activity is a sensitive indicator of lead exposure

Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1576-1582 ◽  
Author(s):  
CR Zerez ◽  
MD Wong ◽  
KR Tanaka
Keyword(s):  
Lead Exposure ◽  
Nicotinamide Adenine Dinucleotide ◽  
Deae Cellulose ◽  
Human Erythrocytes ◽  
Sensitive Indicator ◽  
Nicotinamide Adenine ◽  
Partial Purification ◽  
Synthetase Activity ◽  
Ph Optimum ◽  
Nad Synthetase

Abstract We have examined properties of nicotinamide adenine dinucleotide (NAD) synthetase from human erythrocytes. The enzyme was found to be cold labile and extremely unstable in crude hemolysate, with complete loss of activity occurring after 24 hours at 4 degrees C. However, maintenance of crude hemolysate at 20 to 25 degrees C in the presence of EDTA and KCl increased NAD synthetase stability substantially (half- life = 10 days). Using these conditions, NAD synthetase was purified 3,100-fold with a 29% yield using DEAE-cellulose column chromatography, ammonium sulfate fractionation, and dialysis. The apparent Michaelis- Menten constants for nicotinic acid adenine dinucleotide (NAAD), adenosine triphosphate, Mg2+, glutamine, and K+ were 0.108, 0.154, 1.36, 2.17, and 8.32 mmol/L, respectively. The pH optimum ranged between 6.8 and 7.4, and the molecular weight was estimated to be 483 +/- 5 Kd. The enzyme was markedly inhibited by Pb2+ and Zn2+, with concentrations necessary for 50% inhibition of activity of 1.3 and 2.0 mumol/L, respectively. The incubation of intact red blood cells with lead followed by rigorous washing to remove lead abolished nearly all NAD synthetase activity. In contrast, glucose-6-phosphate dehydrogenase activity, which is not sensitive to lead, was unaffected, whereas pyrimidine 5′-nucleotidase activity, which is sensitive to lead, was decreased 30% to 50% under these conditions. More importantly, patients with lead overburden (34 to 72 micrograms Pb2+/dL blood) all had markedly decreased NAD synthetase activity. These data together with other results suggest that erythrocyte NAD synthetase activity is a sensitive indicator of lead exposure in humans.

Identification, purification, and characterization of phosphotyrosine-specific protein phosphatases from cultured chicken embryo fibroblasts

1984 ◽  
Vol 4 (6) ◽  
pp. 1003-1012
Author(s):  
R L Nelson ◽  
P E Branton
Keyword(s):  
Chicken Embryo ◽  
Protein Phosphatases ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Soluble Form ◽  
Ph Optimum ◽  
Cell Extracts ◽  
Phosphoprotein Phosphatases ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Tyrosine phosphorylation catalyzed by a unique class of protein kinases is an important process in both normal cell proliferation and oncogenic transformation. In this study, phosphoprotein phosphatases specific for the dephosphorylation of phosphotyrosine residues were partially purified from secondary chicken embryo fibroblasts, using 32P-labeled immunoglobulin G phosphorylated by pp60src as substrate. Crude cell extracts contained ca. 70% of the activity in the soluble form and ca. 30% associated with a crude membrane fraction. The soluble activity was purified by using DEAE-cellulose and carboxymethyl cellulose column chromatography and gel filtration, and at least three enzyme species of apparent Mr 55,000 (pTPI), 50,000 (pTPII), and 95,000 (pTPIII)--comprising ca. 20, 45, and 35%, respectively, of the total activity--were resolved. All three enzymes possessed somewhat similar properties. They had a pH optimum of about 7.4, they were inhibited by Zn2+, vanadate, ATP, and ADP, and they were unaffected by divalent metal cations, EDTA, and F- under standard assay conditions employing a physiological ionic strength. These properties suggest that they represent a class of enzymes distinct from well-known phosphoseryl-phosphothreonyl-protein phosphatases and that dephosphorylation of phosphotyrosine-containing proteins may be carried out by a unique family of phosphoprotein phosphatases. Transformation by Rous sarcoma virus resulted in a small increase in phosphotyrosyl-protein phosphatase activity.

Enzymatic sulfation of steroids. V. Partial purification and some properties of sulfotransferase III, the major glucocorticoid sulfotransferase of liver cytosols from male rats

1978 ◽  
Vol 56 (11) ◽  
pp. 1028-1035 ◽  
Author(s):  
Sanford S. Singer ◽  
James Gebhart ◽  
Edward Hess
Keyword(s):  
Molecular Weight ◽  
Sulfhydryl Groups ◽  
Male Rats ◽  
Partial Purification ◽  
Ph Optimum ◽  
Fold Enrichment ◽  
Competitive Inhibitors ◽  
Sequential Mechanism ◽  
Inhibition Studies ◽  
Estradiol 17Β

This manuscript describes purification of sulfotransferase III (STIII), the major hepatic glucocorticoid sulfotransferase of male rats, 77.8 ± 16 fold from cytosol. This represents a probable 250–345 fold enrichment, compared with homogenates. Purified STIII has a molecular weight of 61 500 ± 2500 from Sephadex G-100 chromatography. It is markedly activated by 5 mM divalent Ba, Ca, Co, Cr, Mg, Mn, and Ni salts; inhibited strongly by 5 mM divalent Zn and Cd; and unaffected by 8 mM ADP, ATP, and AMP. Comparison of the ability of purified STIII to sulfate equimolar Cortisol, estradiol-17β, testosterone, and dehydroepiandrosterone suggests that the enzyme may sulfate glucocorticoids preferentially. However, its Cortisol sulfotransferase activity is inhibited by a variety of steroids. Of these, dehydroepiandrosterone, dexamethasone, and progesterone were tested extensively. They were found to be competitive inhibitors. STIII has a sharp pH optimum at pH 6.0 ± 0.1. However, it is routinely assayed at pH 6.8, as explained in the text. It exhibits a sequential mechanism and Km values of 6.82 ± 1.2 and 6.28 ± 0.64 μM for Cortisol and 3′-phosphoadenosine-5′-phosphosulfate, respectively. It also possesses essential sulfhydryl groups, as shown by p-hydroxymercuribenzoate inhibition studies.

scholarly journals UDP-glucose:solasodine glucosyltransferase from eggplant (Solanum melongena L.) leaves: partial purification and characterization.

1997 ◽  
Vol 44 (1) ◽  
pp. 43-53 ◽  
Author(s):  
C Paczkowski ◽  
M Kalinowska ◽  
Z A Wojciechowski
Keyword(s):  
Molecular Mass ◽  
Solanum Melongena ◽  
Divalent Metal ◽  
Partial Purification ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Ph Optimum ◽  
Cytosol Fraction ◽  
Ammonium Sulphate Precipitation ◽  
Unripe Fruits

Uridine 5'-diphosphoglucose-dependent glucosyltransferase which catalyzes the glycosylation of solasodine i.e. UDP-glucose:solasodine glucosyltransferase, is present in leaves, roots, unripe fruits and unripe seeds of eggplant (Solanum melongena L.). The glucosylation product is chromatographically identical with authentic solasodine 3 beta-D-monoglucoside, a putative intermediate in the biosynthesis of solasodine-based glycoalkaloids characteristic of the eggplant. The enzyme was purified about 50-fold from crude cytosol fraction of eggplant leaves by ammonium sulphate precipitation and column chromatography on Q-Sepharose and Sephadex G-100. The native enzyme has a molecular mass of approx. 55 kDa and pH optimum of 8.5. Divalent metal ions are not required for its activity but the presence of free-SH groups is essential. Besides solasodine (Km = 0.04 microM), the enzyme effectively glucosylates tomatidine, another steroidal alkaloid of the spirosolane type, but it is virtually inactive towards the solanidane-type steroidal alkaloids such as solanidine or demissidine. The enzyme is specific for UDP-glucose (Km = 2.1 microM) since unlabelled ADP-, GDP-, CDP- or TDP-glucose could not effectively compete with UDP-[14C]glucose used as the sugar donor for solasodine glucosylation. Moreover, no synthesis of labelled solasodine galactoside was observed when UDP-[14C]glucose was replaced with UDP-[14C]galactose.

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