THE SUBCELLULAR DISTRIBUTION AND NUCLEOTIDE SPECIFICITIES OF Na+, K+-STIMULATED ADENOSINE TRIPHOSPHATASE AND [14C]ADENOSINE DIPHOSPHATE-ADENOSINE TRIPHOSPHATE EXCHANGE REACTIONS IN RAT BRAIN

1968 ◽  
Vol 15 (6) ◽  
pp. 499-509 ◽  
Author(s):  
W. L. Stahl
Keyword(s):  
Rat Brain ◽  
Adenosine Triphosphate ◽  
Subcellular Distribution ◽  
Adenosine Triphosphatase ◽  
Adenosine Diphosphate ◽  
Exchange Reactions

Effects of near-infra-red laser irradiation on adenosine triphosphate and adenosine diphosphate contents of rat brain tissue

2002 ◽  
Vol 323 (3) ◽  
pp. 207-210 ◽  
Author(s):  
Noriko Mochizuki-Oda ◽  
Yosky Kataoka ◽  
Yilong Cui ◽  
Hisao Yamada ◽  
Manabu Heya ◽  
...  
Keyword(s):  
Rat Brain ◽  
Laser Irradiation ◽  
Brain Tissue ◽  
Adenosine Triphosphate ◽  
Adenosine Diphosphate ◽  
Infra Red ◽  
Rat Brain Tissue

scholarly journals Flexibility of an Active Center in Sodium-Plus-Potassium Adenosine Triphosphatase

1969 ◽  
Vol 54 (1) ◽  
pp. 306-326 ◽  
Author(s):  
R. L. Post ◽  
S. Kume ◽  
T. Tobin ◽  
B. Orcutt ◽  
A. K. Sen
Keyword(s):  
Active Center ◽  
Adenosine Triphosphate ◽  
Adenosine Triphosphatase ◽  
Plasma Membranes ◽  
Adenosine Diphosphate ◽  
Ion Concentration ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Intact Cells ◽  
Electrophoretic Patterns

In plasma membranes of intact cells an enzymatic pump actively transports sodium ions inward and potassium ions outward. In preparations of broken membranes it appears as an adenosine triphosphatase dependent on magnesium, sodium, and potassium ions together. In this adenosine triphosphatase a phosphorylated intermediate is formed from adenosine triphosphate in the presence of sodium ions and is hydrolyzed with the addition of potassium ions. The normal intermediate was not split by adenosine diphosphate. However, selective poisoning by N-ethylmaleimide or partial inhibition by a low magnesium ion concentration yielded an intermediate split by adenosine diphosphate and insensitive to potassium ions. Pulse experiments on the native enzyme supported further a hypothesis of a sequence of phosphorylated forms, the first being made reversibly from adenosine triphosphate in the presence of sodium ion and the second being made irreversiblyfrom the first and hydrolyzed in the presence of potassium ion. The cardioactive steriod inhibitor, ouabain, appeared to combine preferentially with the second form. Phosphorylation was at the same active site according to electrophoretic patterns of proteolytic phosphorylated fragments of both reactive forms. It is concluded that there is a conformational change in the active center for phosphorylation during the normal reaction sequence. This change may be linked to one required theoretically for active translocation of ions across the cell membrane.

scholarly journals Altered chemomechanical coupling causes impaired motility of the kinesin-4 motors KIF27 and KIF7

2018 ◽  
Vol 217 (4) ◽  
pp. 1319-1334 ◽  
Author(s):  
Yang Yue ◽  
T. Lynne Blasius ◽  
Stephanie Zhang ◽  
Shashank Jariwala ◽  
Benjamin Walker ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Division ◽  
Adenosine Triphosphate ◽  
Adenosine Triphosphatase ◽  
Adenosine Diphosphate ◽  
Microtubule Dynamics ◽  
Microtubule Organization ◽  
High Affinity ◽  
Chemomechanical Coupling ◽  
Mechanistic Basis

Kinesin-4 motors play important roles in cell division, microtubule organization, and signaling. Understanding how motors perform their functions requires an understanding of their mechanochemical and motility properties. We demonstrate that KIF27 can influence microtubule dynamics, suggesting a conserved function in microtubule organization across the kinesin-4 family. However, kinesin-4 motors display dramatically different motility characteristics: KIF4 and KIF21 motors are fast and processive, KIF7 and its Drosophila melanogaster homologue Costal2 (Cos2) are immotile, and KIF27 is slow and processive. Neither KIF7 nor KIF27 can cooperate for fast processive transport when working in teams. The mechanistic basis of immotile KIF7 behavior arises from an inability to release adenosine diphosphate in response to microtubule binding, whereas slow processive KIF27 behavior arises from a slow adenosine triphosphatase rate and a high affinity for both adenosine triphosphate and microtubules. We suggest that evolutionarily selected sequence differences enable immotile KIF7 and Cos2 motors to function not as transporters but as microtubule-based tethers of signaling complexes.

UNCOUPLING OF OXIDATIVE PHOSPHORYLATION BY VANADATE

1966 ◽  
Vol 44 (7) ◽  
pp. 983-988 ◽  
Author(s):  
John N. Hathcock ◽  
C. H. Hill ◽  
S. B. Tove
Keyword(s):  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Adenosine Triphosphate ◽  
Adenosine Diphosphate ◽  
Liver Mitochondria ◽  
In Vitro Studies ◽  
Exchange Reactions ◽  
Uncoupling Of Oxidative Phosphorylation

The addition of ammonium metavanadate to the diet of chicks at a level to supply 25 parts per million vanadium uncoupled oxidative phosphorylation in mitochondria isolated from the livers. In vitro studies revealed that 1 mM vanadate uncoupled oxidative phosphorylation in liver mitochondria. This uncoupling was manifest whether succinate or β-hydroxybutyrate was used as the substrate, suggesting that all three phosphorylating sites associated with electron transport were uncoupled.At a concentration of 0.1 mM, vanadate increased the destruction of adenosine triphosphate by mitochondria. As the concentration of vanadate was increased the destruction of adenosine triphosphate became progressively less. The exchange reactions of adenosine triphosphate with orthophosphate and with adenosine diphosphate, catalyzed by liver mitochondria, were inhibited by 0.1 mM vanadate. These results suggest the possibility that the known toxic effects of vanadium in vivo are related to the uncoupling of oxidative phosphorylation.

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