COALESCENCE AS A FACTOR IN SOLVENT STIMULATION OF PLASTID PHOSPHATIDASE C ACTIVITY

1957 ◽  
Vol 35 (2) ◽  
pp. 119-126 ◽  
Author(s):  
Morris Kates ◽  
Paul R. Gorham
Keyword(s):  
Enzymatic Activity ◽  
Petroleum Ether ◽  
Ethyl Ether ◽  
Enzymatic Reaction ◽  
Ethyl Butyrate ◽  
Insoluble Complex ◽  
Ether Extraction ◽  
Propyl Ketone ◽  
Stimulation Of

Solvents which stimulate plastid phosphatidase C activity (e.g., ethyl ether, propyl ketone, and ethyl butyrate) have been observed (microscopically) to produce coalescence of lecithin and chloroplast phases, while those which do not stimulate the reaction (e.g., chloroform and petroleum ether) do not produce coalescence. In the ethyl ether-stimulated reaction, all of the original enzymatic activity was associated with the coalesced material, and the lecithin apparently formed an ether-insoluble complex with the chloroplasts; no enzymatic activity appeared in either the aqueous or ether phases. Ether extraction of chloroplasts alone did not liberate the enzyme from the plastids, and the presence of this stimulating solvent was still necessary for reaction with the substrate to occur. It is concluded that stimulating solvents achieve their effect primarily by causing substrate and plastid phases to coalesce and that the enzymatic reaction actually proceeds in the coalesced phase.

COALESCENCE AS A FACTOR IN SOLVENT STIMULATION OF PLASTID PHOSPHATIDASE C ACTIVITY

1957 ◽  
Vol 35 (1) ◽  
pp. 119-126 ◽  
Author(s):  
Morris Kates ◽  
Paul R. Gorham
Keyword(s):  
Enzymatic Activity ◽  
Petroleum Ether ◽  
Ethyl Ether ◽  
Enzymatic Reaction ◽  
Ethyl Butyrate ◽  
Insoluble Complex ◽  
Ether Extraction ◽  
Propyl Ketone ◽  
Stimulation Of

Solvents which stimulate plastid phosphatidase C activity (e.g., ethyl ether, propyl ketone, and ethyl butyrate) have been observed (microscopically) to produce coalescence of lecithin and chloroplast phases, while those which do not stimulate the reaction (e.g., chloroform and petroleum ether) do not produce coalescence. In the ethyl ether-stimulated reaction, all of the original enzymatic activity was associated with the coalesced material, and the lecithin apparently formed an ether-insoluble complex with the chloroplasts; no enzymatic activity appeared in either the aqueous or ether phases. Ether extraction of chloroplasts alone did not liberate the enzyme from the plastids, and the presence of this stimulating solvent was still necessary for reaction with the substrate to occur. It is concluded that stimulating solvents achieve their effect primarily by causing substrate and plastid phases to coalesce and that the enzymatic reaction actually proceeds in the coalesced phase.

Determination of serum aminotransferases: activation by pyridoxal-5'-phosphate in relation to substrate concentration.

1979 ◽  
Vol 25 (1) ◽  
pp. 55-59 ◽  
Author(s):  
J C Hafkenscheid ◽  
C C Dijt
Keyword(s):  
Enzymatic Activity ◽  
Serum Sample ◽  
Aspartate Aminotransferase ◽  
Substrate Concentration ◽  
Enzymatic Reaction ◽  
Reaction Medium ◽  
Aminotransferase Activity ◽  
Serum Aminotransferases ◽  
Stimulation Of

Abstract To investigate the activation of aspartate- and alanine aminotransferases by pyridoxal-5'-phosphate, we determined the enzymatic activity in serum in two different ways: (a) Preincubation of the serum alone or the serum with pyridoxal-5'-phosphate and starting the reaction by the addition of the serum sample or the serum sample + coenzyme, respectively. (b) Preincubation of the serum or the serum with pyridoxal-5'-phosphate in the reaction medium and starting the reaction by adding 2-oxoglutarate. There are only small differences in activities of both aminotransferases determined according to these two different methods. The stimulation by pyridoxal-5'-phosphate is also of the same order, when both methods are compared. Further, these enzymatic activities were measured with use of various concentrations of substrates. From our experiments we conclude that the degree of stimulation of the apoenzyme of the two enzymes is independent of which way the enzymatic reaction is carried out or the substrate concentration, except that aspartate aminotransferase activity is more stimulated by the coenzyme at higher 2-oxoglutarate concentrations.

Isolation of Antithrombin III from Normal and α1-Antitrypsin-Deficient Human Plasma

1977 ◽  
Vol 38 (02) ◽  
pp. 0475-0485 ◽  
Author(s):  
Anna D. Borsodi ◽  
Ralph A. Bradshaw
Keyword(s):  
Enzymatic Activity ◽  
Isoelectric Focusing ◽  
Antithrombin Iii ◽  
Factor Xa ◽  
Antithrombin Activity ◽  
Bovine Trypsin ◽  
Normal Plasma ◽  
Antitrypsin Deficiency ◽  
Simplified Procedure ◽  
Stimulation Of

SummaryThe plasma of individuals, hetero- or homozygous for α1-antitrypsin deficiency, contains greatly decreased amounts of antithrombin activity as assayed against factor Xa. However, heparin stimulation of the residual antithrombin activity is observed, which is comparable to that of normal plasma. Antithrombins isolated from both normal and α1-antitrypsin deficient plasma by a simplified procedure are indistinguishable in both properties and yields. The microheterogeneity observed on isoelectric focusing of both preparations can be eliminated by treatment with neuraminidase. Neither purified human antithrombin nor α1-antitrypsin, when assayed against bovine trypsin, is stimulated by heparin. These results clearly establish the unique natures of antithrombin and α1-antitrypsin and show that about 75% of the antithrombin activity measured in normal plasma is due to α1-antitrypsin. Estimates of anti thrombin III activity in normal plasma by assays dependent on enzymatic activity can probably be obtained only in the presence of heparin.

scholarly journals The petroleum ether extraction of Brassica Rapa L. induces apoptosis of Lung adenocarcinoma cells via mitochondria-dependent pathway

2021 ◽  
Author(s):  
Xierenguli Halike ◽  
Jin-Yu Li ◽  
Pengfei Yuan ◽  
Kaimeiliya Yasheng ◽  
Min Chen ◽  
...  
Keyword(s):  
Petroleum Ether ◽  
Brassica Rapa ◽  
Biological Activities ◽  
Petroleum Ether Extract ◽  
Traditional Food ◽  
Ether Extract ◽  
Ether Extraction ◽  
Adenocarcinoma Cells ◽  
Lung Adenocarcinoma Cells ◽  
Dependent Pathway

Brassica rapa L. is one of the most popular traditional food with a variety of biological activities. In this study, the petroleum ether extract of B. rapa was separated by...

scholarly journals Effect of aluminium oxide nanoparticles on the enzymatic activity on microorganisms of activated sludge

2018 ◽  
Vol 44 ◽  
pp. 00033 ◽  
Author(s):  
Nina Doskocz ◽  
Katarzyna Affek ◽  
Monika Załęska-Radziwiłł
Keyword(s):  
Enzymatic Activity ◽  
Activated Sludge ◽  
Hydrolytic Enzymes ◽  
Aluminium Oxide ◽  
Cellular Respiration ◽  
Oxide Nanoparticles ◽  
Oxide Compound ◽  
Commercial Use ◽  
Aluminium Oxide Nanoparticles ◽  
Stimulation Of

The increased production and commercial use of nanoparticles (NPs), combined with a lack of regulation regarding their disposal, may result in the unwanted introduction of NPs to wastewater. Wastewater nutrient removal depends on the metabolisms of activated sludge bacteria and their related key enzymes. Therefore, the aim of this work was to determine the effect of aluminium oxide nanoparticles concentrations on the activated sludge enzymatic activity of microorganisms. Tested nanoparticles inhibition cellular respiration in TTC method in the four highest tested concentrations. Moreover, in most samples observed increase dehydrogenase activity. In this study, nano-Al2O3 also caused a clear stimulation of the activity of hydrolytic enzymes microorganisms of activate sludge. Effects of aluminum oxide (compound in bulk forms) on enzymatic activity were different than in the case of the nano from of Al2O3.

scholarly journals Termite-Repellent Activity and Chemical Composition of West Indian Mahogany Wood, (Swietenia Mahagoni Jacq.) with Special Reference to the P2 Fraction

1969 ◽  
Vol 42 (3) ◽  
pp. 185-195
Author(s):  
Conrado F. Asenjo ◽  
Luis Amorós Marín ◽  
Wanda Torres ◽  
Alice Del Campillo
Keyword(s):  
Petroleum Ether ◽  
Petroleum Ether Extract ◽  
West Indian ◽  
Repellent Activity ◽  
Structural Level ◽  
Ether Extract ◽  
Selective Solvents ◽  
Ether Extraction ◽  
Termite Attack ◽  
Waxy Substance

1. Serial extraction of West Indian mahogany wood with selective solvents was performed. 2. The petroleum ether extract was the only fraction to exhibit promising termite-repellent activity. 3. Mahogany blocks subjected to petroleum ether extraction became susceptible to termite attack. 4. A waxy substance (P2 fraction) separated from the petroleum ether extract at times showed high termite-repellent activity. The termite-repellent principle in the P2 fraction seems to be a labile one, as the termite-repellent activity varied greatly from batch to batch. 5. The P2 fraction is a mixture of two major components and of at least a third minor one. As far as we have been able to determine this mixture, at the elemental level, contains carbon, hydrogen, and oxygen only, while esters have been the only compounds definitely characterized at the structural level.

Increased Site-Specific Phosphorylation of Tyrosine Hydroxylase Accompanies Stimulation of Enzymatic Activity Induced by Cessation of Dopamine Neuronal Activity

1999 ◽  
Vol 55 (2) ◽  
pp. 202-209 ◽  
Author(s):  
Jow Y. Lew ◽  
Antonio Garcia-Espana ◽  
Kwan Y. Lee ◽  
Kenneth D. Carr ◽  
Menek Goldstein ◽  
...  
Keyword(s):  
Tyrosine Hydroxylase ◽  
Enzymatic Activity ◽  
Neuronal Activity ◽  
Site Specific ◽  
Stimulation Of
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