Partial characterization of a soluble ATPase from pea cotyledon mitochondria

1977 ◽  
Vol 55 (8) ◽  
pp. 812-818 ◽  
Author(s):  
Charles Grubmeyer ◽  
Ian Duncan ◽  
Mary Spencer
Keyword(s):  
Partial Characterization ◽  
Mitochondrial Enzyme ◽  
Mammalian Mitochondria ◽  
High Concentrations

A partially purified soluble ATPase (ATP phosphohydrolase, EC 3.6.1.3) from pea cotyledon mitochondria was characterized. Inhibition patterns with azide, NaF, and cold, and a stimulation by 2,4-dinitrophenol were typical of F1-ATPases from mammalian mitochondria. The enzyme hydrolysed GTP, ITP, and ATP, but not CTP, UTP, ADP, or IDP. ATPase and ITPase activities were strongly inhibited by ADP and to a lesser extent by IDP. Distinctive properties of the pea mitochondrial enzyme were activation by high concentrations of CaCl2 and stimulation by NaCl.

The assay and partial characterization of 3β-hydroxysteroid sulfotransferase of the hamster epididymis

1985 ◽  
Vol 63 (1) ◽  
pp. 71-76 ◽  
Author(s):  
M. Bouthillier ◽  
G. Bleau ◽  
A. Chapdelaine ◽  
K. D. Roberts
Keyword(s):  
Organic Phase ◽  
Enzyme Preparation ◽  
Enzymatic Reaction ◽  
Partial Characterization ◽  
Optimal Conditions ◽  
Steroid Nucleus ◽  
Optimum Ph ◽  
High Concentrations

Using a partially purified enzyme preparation obtained from hamster epididymis, a simple assay has been developed to measure the sulfurylation of dehydroisoandrosterone (DHA) and desmosterol in the presence of 3′-phosphoadenosine 5′-phospho[35S]sulfate ([35S]PAPS). After stopping the enzymatic reaction with methanol and KCl, the 35S-labelled steroid sulfates are readily extracted into an organic phase. Optimal conditions for the sulfurylation of the two steroids were compared; optimum pH is 8.7 for DHA and 9.8 for desmosterol. Sulfoconjugation of desmosterol increases with magnesium concentrations up to 6 mM, while 40 mM concentrations of the divalent ion are required for the optimal sulfurylation of DHA. Maximum sulfurylation of these steroids requires the presence of 15 mM cysteine. Michaelis–Menten kinetics are observed with DHA which has an apparent Km of 32 μM, while desmosterol inhibits sulfotransferase activity at high concentrations. Saturation of the enzyme with PAPS results in an allosteric behaviour. Only the 3β-hydroxyl function of the steroid nucleus appears to be an appropriate sulfate acceptor for the epididymal hydroxysteroid sulfotransferase.

Partial characterization of the N-linked oligosaccharides occurring on rat hepatocyte glycoproteins

2010 ◽  
Vol 108 (10) ◽  
pp. 323-329 ◽  
Author(s):  
Marti F. A. Bierhuizen ◽  
Moniek de Wit ◽  
Carin A. R. L. Govers ◽  
Willem van Dijk
Keyword(s):  
Partial Characterization ◽  
Rat Hepatocyte

scholarly journals Localization and Partial Characterization of an Aldehydic Component in Tropocollagen

1966 ◽  
Vol 241 (7) ◽  
pp. 1530-1536
Author(s):  
Marcos Rojkind ◽  
Olga O. Blumenfeld ◽  
Paul M. Gallop
Keyword(s):  
Partial Characterization

scholarly journals Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1757
Author(s):  
Yesica Vicente-Martínez ◽  
Manuel Caravaca ◽  
Antonio Soto-Meca ◽  
Miguel Ángel Martín-Pereira ◽  
María del Carmen García-Onsurbe
Keyword(s):  
Magnetic Nanoparticles ◽  
Nitrate Content ◽  
Adsorption Efficiency ◽  
Experimental Conditions ◽  
Dependent Behavior ◽  
Before And After ◽  
Naoh Solution ◽  
High Concentrations ◽  
Interference Studies

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

scholarly journals Detection and partial characterization of a protein in mouse fibroblasts that binds and inhibits trypsin.

1980 ◽  
Vol 255 (11) ◽  
pp. 5468-5474 ◽  
Author(s):  
R.J. Kirschner ◽  
C.S. Federiuk ◽  
J.P. Ford ◽  
J.A. Shafer
Keyword(s):  
Partial Characterization ◽  
Mouse Fibroblasts
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