Effects of Ethylene, Carbon Dioxide, and Ethylene – Carbon Dioxide Mixtures on the Activities of "Membrane-Containing" and "Highly Purified" Preparations of Adenosine Triphosphatase from Pea-Cotyledon Mitochondria

1974 ◽  
Vol 52 (12) ◽  
pp. 1091-1096 ◽  
Author(s):  
S. S. Malhotra ◽  
Mary Spencer
Keyword(s):  
Carbon Dioxide ◽  
Adenosine Triphosphatase ◽  
Direct Action ◽  
Gas Mixture ◽  
Mitochondrial Atpase ◽  
Enzyme Preparations ◽  
Membrane Bound

From pea-cotyledon mitochondria two types of adenosine triphosphatase (ATP phosphohydrolase) were prepared, "membrane-bound" and "highly purified." Activities of both enzyme preparations were dependent on Mg2+ and were stimulated by Na+ and K+. Ethylene had no effect on the activity of either the "membrane-bound" or the "highly purified" enzyme. Ethylene – carbon dioxide – air mixtures stimulated the activity of the "membrane-bound" but not the "highly purified" ATPase, when Na+ and K+ were present. When these ions were absent, the gas mixture greatly increased the activities of both enzyme preparations. The work shows a direct action of ethylene on an enzyme (mitochondrial ATPase), its dependence on the presence of certain levels of CO2, and the augmentation of the ethylene–CO2 effects by the presence of phospholipids.

scholarly journals Characterization of cuckoo-pint (Arum maculatum) mitochondrial adenosine triphosphatases

1986 ◽  
Vol 233 (3) ◽  
pp. 839-844 ◽  
Author(s):  
P P J Dunn ◽  
A R Slabas ◽  
A L Moore
Keyword(s):  
Adenosine Triphosphatase ◽  
Kinetic Properties ◽  
Ph Profile ◽  
Enzyme Preparations ◽  
Adenosine Triphosphatases ◽  
Membrane Bound ◽  
Cold Stability ◽  
Arum Maculatum ◽  
Guanosine Triphosphatase ◽  
Soluble Enzymes

The catalytic properties of cuckoo-pint (Arum maculatum) mitochondrial adenosine triphosphatase have been analysed. The pH profile, effect of inhibitors, cold-stability and substrate specificity are characteristic of mitochondrial adenosine triphosphatases, although a high guanosine triphosphatase activity does appear to be restricted to plant mitochondrial adenosine triphosphatases. The kinetic properties of nucleoside 5′-triphosphate hydrolysis by membrane-bound and soluble enzymes have been studied by means of double-reciprocal plots. These plots were linear in the absence of an activating anion, which may indicate that the catalytic and/or regulatory mechanism of Arum maculatum adenosine triphosphatase is different from that of other enzyme preparations. It is suggested that the differences in subunit composition of plant and mammalian adenosine triphosphatases reported previously [Dunn, Slabas & Moore (1985) Biochem. J. 225, 821-824] are structurally, rather than functionally, significant.

scholarly journals Evidence that Taste Buds are not Present on the Human Adult Uvula

2002 ◽  
Vol 81 (7) ◽  
pp. 456-457 ◽  
Author(s):  
Bryan T. Ambro ◽  
Edmund A. Pribitkin ◽  
Linda Wysocki ◽  
Joseph G. Brand ◽  
William M. Keane
Keyword(s):  
Carbon Dioxide ◽  
Surgical Procedures ◽  
Carbon Dioxide Laser ◽  
Adenosine Triphosphatase ◽  
Taste Buds ◽  
Taste Perception ◽  
Taste Receptors ◽  
High Concentration ◽  
Human Adult ◽  
Membrane Bound

We conducted a study to investigate whether taste buds are present on the human adult uvula. Our impetus was to determine whether surgical procedures that involve removal of the uvula can affect taste perception. Five human uvulae were removed via a modified carbon dioxide laser-assisted uvulopalatoplasty in an outpatient office setting. The uvulae were serially sectioned and stained with a solution specific for membrane-bound calcium-modulated adenosine triphosphatase, a high concentration of which is found in taste receptors. Examination of the stained sections under light microscopy failed to show that any taste receptors were present in any of the uvulae. This finding suggests that the taste disturbances noted after surgical procedures involving removal of the uvula are not attributable to a loss of taste receptors.

scholarly journals A method for determining the adenosine triphosphatase content of energy-transducing membranes. reaction of 4-chloro-7-nitrobenzofurazan with the adenosine triphosphatase of bovine heart submitochondrial particles

1976 ◽  
Vol 159 (2) ◽  
pp. 347-353 ◽  
Author(s):  
S J Ferguson ◽  
W J Lloyd ◽  
G K Radda
Keyword(s):  
Mitochondrial Membrane ◽  
Adenosine Triphosphatase ◽  
Plasma Membranes ◽  
Single Amino Acid ◽  
Mitochondrial Atpase ◽  
Inner Mitochondrial Membrane ◽  
Submitochondrial Particles ◽  
Bovine Heart ◽  
Single Amino Acid Residue ◽  
Membrane Bound

1. Modification of a single amino acid residue by introduction of the nitrobenzofurazan group inactivates mitochondrial ATPase (adenosine triphosphatase) when membrane-bound in submitochondrial particles. The similarity between the reactions of both membrane-bound and isolated ATPase with 4-chloro-7-nitrobenzofurazan indicates that the single essential tryosine residue identified in the isolated enzyme [Ferguson, Loyd, Lyons & Radda (1975) Eur. J. Biochem. 54, 117-126] Is also a feature of the membrane-bound ATPase. 2. A procedure is presented for estimating the ATPase content of the inner mitochondrial membrane. It is based on the specificity of the incorporation of the nitrobenzofurazan group, and the ready removal of this group by compounds that contain a thiol group. This method indicates that 8.5% of the membrane protein is ATPase. The procedure should be applicable to the titration of the energy-transducing ATPases of bacterial plasma membranes and of the thylakoid membranes of chloroplasts. 3. Combination of the data obtained on the ATPase content of the bovine heart inner mitochondrial membrane with a titration of the cytochrome bc1 complex with antimycin indicates that these two components of the membrane are present in approximately equal amounts.

scholarly journals PROBLEMS ASSOCIATED WITH THE DEMONSTRATION BY LEAD METHODS OF ADENOSINE TRIPHOSPHATASE ACTIVITY IN RESIDENT PERITONEAL MACROPHAGES AND EXUDATE MONOCYTES OF THE GUINEA PIG

1973 ◽  
Vol 21 (5) ◽  
pp. 488-498 ◽  
Author(s):  
R. E. POELMANN ◽  
W. T. DAEMS ◽  
E. J. VAN LOHUIZEN
Keyword(s):  
Plasma Membrane ◽  
Guinea Pig ◽  
Microscopic Study ◽  
Heterogeneous Nucleation ◽  
Adenosine Triphosphatase ◽  
Peritoneal Macrophages ◽  
Electron Microscopic ◽  
Adenosine Triphosphatase Activity ◽  
Eosinophilic Granulocytes ◽  
Membrane Bound

This cytochemical and electron microscopic study on peritoneal macrophages of the guinea pig has raised doubts concerning the validity of lead methods for the demonstration of plasma membrane-bound adenosine triphosphatase activity. The problems encountered are inherent in the use of lead ions as a capture reagent. The nonenzymatically formed precipitates reflect sites of heterogeneous nucleation specific for certain kinds of cells, e.g., resident peritoneal macrophages, eosinophilic granulocytes and, to a lesser degree, exudate monocytes. This type of precipitation is also catalyzed on the surface of nonbiologic matrices such as latex particles. Enzymatic processes may well occur, but they cannot be distinguished from nonenzymatic processes.

Preservation of freshness of yellowtail fillet packaged using carbon dioxide-nitrogen gas mixture

1989 ◽  
Vol 2 (3) ◽  
pp. 135-139 ◽  
Author(s):  
Matsui Yasuda ◽  
Hajime Nishino ◽  
Tokiko Chiba ◽  
Hisako Nakano ◽  
Michio Yokoyama
Keyword(s):  
Carbon Dioxide ◽  
Gas Mixture ◽  
Nitrogen Gas

Characterization of the Metamitron Deaminating Enzyme Activity from Sugar Beet ( Beta vulgaris L.) Leaves

1979 ◽  
Vol 34 (11) ◽  
pp. 948-950 ◽  
Author(s):  
Carl Fedtke ◽  
Robert R. Schmidt
Keyword(s):  
Cytochrome C ◽  
Sugar Beet ◽  
Electron Donor ◽  
Nitrogen Atmosphere ◽  
Enzyme Preparations ◽  
Reducing Conditions ◽  
Trade Name ◽  
Membrane Bound

Abstract The enzymatic activity from sugar beet leaves which is responsible for the detoxification of the herbicide metamitron (4-amino-4,5-dihydro-3-methyl-6-phenyl-1, 2, 4-triazin-5-one, trade name Goltix®) has been characterized in vitro. The detoxification occurs by rapid deamination in vivo as well as in vitro. However, the deamination in vitro is only maximal under reducing conditions, i. e. with an electron donor and in a nitrogen atmosphere. The electron donor may be cystein, glutathione, dithionite or ascorbate. The enzymatic deamination further requires the addition of cytochrome c and a “supernatant factor”, which may be replaced by FMN, FAD or DCPIP. However, in the presence of FMN or DCPIP cytochrome c is not essential but only stimulatory. The partic­ulate as well as the soluble metamitron deaminating enzyme preparations obtained take up oxygen when supplied with cysteine and FMN. The particulate enzyme appears in the peroxysome-fraction. It is therefore suggested, that the enzymatic deamination of metamitron in sugar beet leaves is mediated by a proxisomal membrane bound electron transport system which alternatively may reduce oxygen or metamitron (deaminating).

scholarly journals Membrane isolation on polylysine-coated beads. Plasma membrane from HeLa cells.

1977 ◽  
Vol 75 (1) ◽  
pp. 119-134 ◽  
Author(s):  
C M Cohen ◽  
D I Kalish ◽  
B S Jacobson ◽  
D Branton
Keyword(s):  
Adenosine Triphosphatase ◽  
Wheat Germ ◽  
Plasma Membranes ◽  
Cell Attachment ◽  
Isolation Procedure ◽  
Chemical Analyses ◽  
Isolation Techniques ◽  
Cell Plasma ◽  
Membrane Bound ◽  
Membrane Isolation

HeLa cell plasma membranes have been purified after binding cells to polylysine-coated polyacrylamide beads. Cell attachment to beads and membrane recovery were maximal in a sucrose-acetate buffer, pH 5.0, at 25 degrees C. Measurements of ouabain-sensitive NaK-adenosine triphosphatase, membrane-bound 125I-wheat germ agglutinin, and chemical analyses showed that membranes on beads were of comparable or greater purity than membranes isolated by conventional methods. Because the isolation procedure is rapid (approximately 2.5 h), and produces membranes whose protoplasmic surfaces are fully exposed, it should be a useful supplement to standard isolation techniques.

scholarly journals Molecular Simulations of CO2/CH4, CO2/N2 and N2/CH4 Binary Mixed Hydrates

2021 ◽  
Vol 83 (3) ◽  
pp. 372-378
Author(s):  
A. A. Sizova ◽  
S. A. Grintsevich ◽  
M. A. Kochurin ◽  
V. V. Sizov ◽  
E. N. Brodskaya
Keyword(s):  
Carbon Dioxide ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Gas Hydrates ◽  
Molecular Simulations ◽  
Gas Mixtures ◽  
Gas Mixture ◽  
Grand Canonical Monte Carlo ◽  
Multicomponent Gas ◽  
Grand Canonical

Abstract Grand canonical Monte Carlo simulations were performed to study the occupancy of structure I multicomponent gas hydrates by CO2/CH4, CO2/N2, and N2/CH4 binary gas mixtures with various compositions at a temperature of 270 K and pressures up to 70 atm. The presence of nitrogen in the gas mixture allows for an increase of both the hydrate framework selectivity to CO2 and the amount of carbon dioxide encapsulated in hydrate cages, as compared to the CO2/CH4 hydrate. Despite the selectivity to CH4 molecules demonstrated by N2/CH4 hydrate, nitrogen can compete with methane if the gas mixture contains at least 70% of N2.

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