The plasma membrane (Mg2+)-dependent adenosine triphosphatase from the human erythrocyte is not an ion pump

1984 ◽  
Vol 80 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Michael Forgac ◽  
Lewis Cantley
Keyword(s):  
Plasma Membrane ◽  
Human Erythrocyte ◽  
Adenosine Triphosphatase ◽  
Ion Pump

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

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.

scholarly journals ULTRASTRUCTURAL LOCALIZATION OF Mg++-DEPENDENT DINITROPHENOL-STIMULATED ADENOSINE TRIPHOSPHATASE IN HUMAN BLOOD PLATELETS

1967 ◽  
Vol 15 (5) ◽  
pp. 267-272 ◽  
Author(s):  
VICTOR G. VETHAMANY ◽  
SYDNEY S. LAZARUS
Keyword(s):  
Enzyme Activity ◽  
Plasma Membrane ◽  
Human Blood ◽  
Adenosine Triphosphatase ◽  
Blood Platelets ◽  
Ultrastructural Localization ◽  
Human Platelets ◽  
Structural Localization ◽  
Adenosine Triphosphatase Activity ◽  
Human Blood Platelets

Fine structural localization of adenosine triphosphatase activity was studied in human platelets briefly fixed in cold formol calcium and then incubated in lead medium with added dinitrophenol. Under these conditions, the Mg++-dependent dinitrophenol-stimulated adenosine triphosphatase of platelet mitochondria was demonstrated, but neither granules nor plasma membrane showed enzyme activity.

Fine-Structural Localization of Adenosine Triphosphatase in the Rectum of Calliphora

1968 ◽  
Vol 3 (1) ◽  
pp. 17-32
Author(s):  
M. J. BERRIDGE ◽  
B. L. GUPTA
Keyword(s):  
Plasma Membrane ◽  
Adenosine Triphosphatase ◽  
Plasma Membranes ◽  
Fluid Transport ◽  
Microsomal Fraction ◽  
Adenosine Diphosphate ◽  
Structural Basis ◽  
Osmotic Gradient ◽  
Ph Optimum ◽  
Structural Localization

Adenosine triphosphatase (ATPase) activity in the rectal papillae of Calliphora has been studied by biochemical and histochemical techniques. The microsomal fraction contained a Mg2+-activated ATPase with a pH optimum of 8.0. The enzyme was not stimulated by the addition of Na+ plus K+ and was insensitive to ouabain. Histochemical studies using modifications of the Wachstein-Meisel method showed that at pH 7.2 this Mg2+-activated ATPase was specifically localized on the intracellular surface of the lateral plasma membranes. A similar though less intense reaction was obtained with adenosine diphosphate and inosine triphosphate, but not with guanosine triphosphate, uridine triphosphate or β-glycerophosphate as substrates. At an acid pH (6.6-6.8), very little reaction occurred on the lateral plasma membrane but some reaction product was present in mitochondria and nuclei. Very little enzyme activity was found in the flattened rectal epithelium. These results are discussed in relation to the available data on transport ATPases and on the structural basis of fluid transport by rectal papillae. It is proposed that the ATPase localized on the stacks of lateral plasma membrane may be involved with ion secretion into the intercellular spaces to create the osmotic gradient necessary to extract water from the lumen.

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