Studies of Tetrakis(trifluoroacetate) Dirhodium. 2.†A Pi Complex of Hexamethylbenzene with Tetrakis(trifluoroacetate) Dirhodium(II,II)

1999 ◽  
Vol 18 (14) ◽  
pp. 2724-2726 ◽  
Author(s):  
F. Albert Cotton ◽  
Evgeny V. Dikarev ◽  
Salah-Eddine Stiriba
Keyword(s):  
Pi Complex

scholarly journals The role of ADP in the modulation of the calcium-efflux pathway in rat brain mitochondria

1985 ◽  
Vol 225 (1) ◽  
pp. 41-49 ◽  
Author(s):  
J Vitorica ◽  
J Satrústegui
Keyword(s):  
Rat Brain ◽  
Binding Sites ◽  
Tricarboxylic Acid Cycle ◽  
Brain Mitochondria ◽  
Ruthenium Red ◽  
Calcium Efflux ◽  
Rat Brain Mitochondria ◽  
Pi Complex ◽  
Efflux Pathway

The role of ADP in the regulation of Ca2+ efflux in rat brain mitochondria was investigated. ADP was shown to inhibit Ruthenium-Red-insensitive H+- and Na+-dependent Ca2+-efflux rates if Pi was present, but had no effect in the absence of Pi. The primary effect of ADP is an inhibition of Pi efflux, and therefore it allows the formation of a matrix Ca2+-Pi complex at concentrations above 0.2 mM-Pi and 25 nmol of Ca2+/mg of protein, which maintains a constant free matrix Ca2+ concentration. ADP inhibition of Pi and Ca2+ efflux is nucleotide-specific, since in the presence of oligomycin and an inhibitor of adenylate kinase ATP does not substitute for ADP, is dependent on the amount of ADP present, and requires ADP concentrations in excess of the concentrations of translocase binding sites. Brain mitochondria incubated with 0.2 mM-Pi and ADP showed Ca2+-efflux rates dependent on Ca2+ loads at Ca2+ concentrations below those required for the formation of a Pi-Ca2+ complex, and behaved as perfect cytosolic buffers exclusively at high Ca2+ loads. The possible role of brain mitochondrial Ca2+ in the regulation of the tricarboxylic acid-cycle enzymes and in buffering cytosolic Ca2+ is discussed.

scholarly journals Relationship Between Severity of Fibrinolysis Based on Rotational Thromboelastometry and Conventional Fibrinolysis Markers

2020 ◽  
Vol 26 ◽  
pp. 107602962093300
Author(s):  
Tomoyo Saito ◽  
Mineji Hayakawa ◽  
Yoshinori Honma ◽  
Asumi Mizugaki ◽  
Tomonao Yoshida ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Degradation Products ◽  
Plasminogen Activator Inhibitor ◽  
University Hospital ◽  
Extrinsic Pathway ◽  
Rotational Thromboelastometry ◽  
Fibrin Degradation Products ◽  
Pi Complex ◽  
Fibrinolytic Parameters ◽  
Hospital Cardiac Arrest

The association between severity of fibrinolysis, ascertained by rotational thromboelastometry to diagnose hyperfibrinolysis in patients with out-of-hospital cardiac arrest (OHCA), and conventional fibrinolysis markers (ie, tissue-plasminogen activator [t-PA], plasminogen, α2-plasmin inhibitor [α2-PI], and plasminogen activator inhibitor [PAI]) with key roles in the fibrinolytic system was investigated. This prospective observational study included 5 healthy volunteers and 35 patients with OHCA from the Hokkaido University Hospital. Blood samples were drawn immediately upon admission to the emergency department. Assessments of the extrinsic pathway using tissue factor activation (EXTEM) and of fibrinolysis by comparison with EXTEM after aprotinin addition (APTEM) were undertaken. Conventional coagulation and fibrinolysis markers were measured in the stored plasma samples. Significant hyperfibrinolysis observed in EXTEM disappeared in APTEM. Patients exhibited significantly higher levels of fibrinogen/fibrin degradation products, plasmin–α2-PI complex, and t-PA but lower levels of fibrinogen, plasminogen, and α2-PI than healthy controls. The PAI level was unchanged. Fibrinolytic parameters of EXTEM correlated with levels of lactate and conventional fibrinolysis markers, especially t-PA. Increased t-PA activity and decreased plasminogen and α2-PI significantly correlated with increased severity of fibrinolysis (hyperfibrinolysis).

Reactions of New Pi-Complex Catalysts

1962 ◽  
pp. 137-144 ◽  
Author(s):  
GÜNTHER WILKE ◽  
BORISLAV BOGDANOVIČ ◽  
PAUL HEIMBACH ◽  
MICHAEL KRÖNER ◽  
ERNST WILLI MÜLLER
Keyword(s):  
Pi Complex

Secondary isotope effects on pi-complex formation

1964 ◽  
Vol 8 (3-4) ◽  
pp. 339-346 ◽  
Author(s):  
E. A. Halevi ◽  
B. Ravid
Keyword(s):  
Complex Formation ◽  
Isotope Effects ◽  
Pi Complex

Copper Resistance Mechanisms of Biomining Bacteria and Archaea Living under Extremely High Concentrations of Metals

2009 ◽  
Vol 71-73 ◽  
pp. 279-282 ◽  
Author(s):  
A. Orell ◽  
C.A. Navarro ◽  
Carlos A. Jerez
Keyword(s):  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Copper Resistance ◽  
Inorganic Polyphosphate ◽  
Resistance Determinants ◽  
High Metal ◽  
Pi Complex ◽  
Cu Resistance ◽  
High Concentrations ◽  
Cu Tolerance

Extremophiles such as the acidophilic Sulfolobus metallicus (Archaea) and Acidithiobacillus ferrooxidans (Bacteria) can resist Cu (CuSO4) concentrations of 200 mM and 800 mM respectively. These microorganisms are important in biomining processes to extract copper and other metals. A. ferrooxidans grown at low Cu concentrations (5 mM) expressed genes coding for ATPases most likely involved in pumping the metal from the cytoplasm to the periplasm of the bacterium. At 100 mM Cu the previous systems were repressed and there was a great induction in the expression of efflux systems known to use the proton motive force energy to export the metal outside the cell. These Cu-resistance determinants from A. ferrooxidans were found to be functional since when expressed in Escherichia coli they conferred higher Cu tolerance to it. Novel Cu-resistance determinants for A. ferrooxidans were found and characterized. S. metallicus possessed at least 2 CopM metallochaperones and 2 CopA ATPases whose expressions were induced by Cu (5 to 50 mM). Furthermore, we previously reported that both microorganisms accumulate high levels of inorganic polyphosphate (PolyP) and that intracellular Cu concentration stimulates polyP hydrolysis. The resulting Pi would then be transported out of the cell as a metal-Pi complex to detoxify the cells. In addition, our results suggest that at high Cu concentrations polyP could also provide energy for the metal efflux. All the data suggest that both biomining microorganisms use different systems to respond to Cu depending on the extracellular concentrations of the metal and suggest that the presence of different additional systems to respond to Cu may explain the extremely high metal resistance of these extremophiles.

scholarly journals Two distinct crossbridge structures observed in actin-G680V mutant S1-ADP-Pi complex.

2001 ◽  
Vol 41 (supplement) ◽  
pp. S189
Author(s):  
T.Q.P. Uyeda ◽  
E. Katayama
Keyword(s):  
Pi Complex
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