In vitro binding of protoheme IX and protoporphyrin IX to components in the matrix of rat liver mitochondria

1979 ◽  
Vol 588 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Arild Tangerås ◽  
Torgeir Flatmark
Keyword(s):  
Rat Liver ◽  
Protoporphyrin Ix ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
The Matrix

In vitro binding of 3,5-di-iodo-L-thyronine to rat liver mitochondria

1994 ◽  
Vol 13 (3) ◽  
pp. 275-282 ◽  
Author(s):  
F Goglia ◽  
A Lanni ◽  
C Horst ◽  
M Moreno ◽  
R Thoma
Keyword(s):  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
In Vitro Binding ◽  
Vitro Binding

In vitro binding of triiodothyronine to rat liver mitochondria

1981 ◽  
Vol 390 (2) ◽  
pp. 120-124 ◽  
Author(s):  
F. Goglia ◽  
J. Torresani ◽  
P. Bugli ◽  
A. Barletta ◽  
G. Liverini
Keyword(s):  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
In Vitro Binding ◽  
Vitro Binding

scholarly journals d-Lactate transport and metabolism in rat liver mitochondria

2002 ◽  
Vol 365 (2) ◽  
pp. 391-403 ◽  
Author(s):  
Lidia de BARI ◽  
Anna ATLANTE ◽  
Nicoletta GUARAGNELLA ◽  
Giovanni PRINCIPATO ◽  
Salvatore PASSARELLA
Keyword(s):  
Lactate Dehydrogenase ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Lactate Metabolism ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
The Matrix ◽  
Inside Out

In the present study we investigated whether isolated rat liver mitochondria can take up and metabolize d-lactate. We found the following: (1) externally added d-lactate causes oxygen uptake by mitochondria [P/O ratio (the ratio of mol of ATP synthesized to mol of oxygen atoms reduced to water during oxidative phosphorylation) = 2] and membrane potential (Δψ) generation in processes that are rotenone-insensitive, but inhibited by antimycin A and cyanide, and proton release from coupled mitochondria inhibited by α-cyanocinnamate, but not by phenylsuccinate; (2) the activity of the putative flavoprotein (d-lactate dehydrogenase) was detected in inside-out submitochondrial particles, but not in mitochondria and mitoplasts, as it is localized in the matrix phase of the mitochondrial inner membrane; (3) three novel separate translocators exist to mediate d-lactate traffic across the mitochondrial inner membrane: the d-lactate/H+ symporter, which was investigated by measuring fluorimetrically the rate of endogenous flavin reduction, the d-lactate/oxoacid antiporter (which mediates both the d-lactate/pyruvate and d-lactate/oxaloacetate exchanges) and d-lactate/malate antiporter studied by monitoring photometrically the appearance of the d-lactate counteranions outside mitochondria. The d-lactate translocators, in the light of their different inhibition profiles separate from the monocarboxylate carrier, were found to differ from each other in the Vmax values and in the inhibition and pH profiles and were shown to regulate mitochondrial d-lactate metabolism in vitro. The d-lactate translocators and the d-lactate dehydrogenase could account for the removal of the toxic methylglyoxal from cytosol, as well as for d-lactate-dependent gluconeogenesis.

scholarly journals Selective permeability of rat liver mitochondria to purified aspartate aminotransferases in vitro

1977 ◽  
Vol 164 (3) ◽  
pp. 685-691 ◽  
Author(s):  
E Marra ◽  
S Doonan ◽  
C Saccone ◽  
E Quagliariello
Keyword(s):  
Rat Liver ◽  
Aspartate Aminotransferase ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Transferase Activity ◽  
Selective Permeability ◽  
The Matrix ◽  
Mitochondrial Aspartate Aminotransferase

1. A method was devised to allow determination of intramitochondrial aspartate amino-transferase activity in suspensions of intact mitochondria. 2. Addition of purified rat liver mitochondrial aspartate aminotransferase to suspensions of rat liver mitochondria caused an apparent increase in the intramitochondrial enzyme activity. No increase was observed when the mitochondria were preincubated with the purified cytoplasmic isoenzyme. 3. These results suggest that mitochondrial aspartate aminotransferase, but not the cytoplasmic isoenzyme, is able to pass from solution into the matrix of intact rat liver mitochondria in vitro. 4. This system may provide a model for studies of the little-understood processes by which cytoplasmically synthesized components are incorporated into mitochondria in vivo.

Transfer of Heme from Mitochondria in Rat Liver Cells

1972 ◽  
Vol 50 (6) ◽  
pp. 633-637 ◽  
Author(s):  
B. Yoda ◽  
L. G. Israels
Keyword(s):  
Rat Liver ◽  
Aminolevulinic Acid ◽  
Surrounding Medium ◽  
Protoporphyrin Ix ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Single Carrier ◽  
Protein Carriers ◽  
Rat Liver Cells

The final steps in heme synthesis take place within mitochondria while the acceptor apoproteins are synthesized on the endoplasmic reticulum. When 14C-δ-aminolevulinic acid is used as a heme precursor in intact rats, measurable 14C-heme is found to be associated with the microsomes within 10 min of intraperitoneal injection. This rapid transfer of heme from mitochondria was studied in vitro using isolated rat liver mitochondria, and protoporphyrin IX and 59Fe as heme precursors. These mitochondria synthesize heme when suspended in whole cell sap and this is only partially reduced by substituting Sephadex G-25 filtered cell sap or sucrose. Mitochondria incubated in G-25 filtered cell sap or sucrose synthesize equivalent amounts of heme but those in sucrose export little heme into the surrounding medium. Heme export from mitochondria is dependent on protein in the suspending medium. In cell sap, heme is associated with multiple proteins and no single carrier was identified. Heme probably makes its way from mitochondria to microsomes via various protein carriers by nonspecific adherence. Microsomal apoproteins or other heme binding proteins then remove the heme from the intermediate carrier as the terminal step.

scholarly journals Uptake of protoporphyrin IX by isolated rat liver mitochondria

1980 ◽  
Vol 188 (2) ◽  
pp. 329-335 ◽  
Author(s):  
M E Koller ◽  
I Romslo
Keyword(s):  
Rat Liver ◽  
Mitochondrial Membrane ◽  
Protoporphyrin Ix ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Inner Mitochondrial Membrane ◽  
Erythropoietic Protoporphyria ◽  
Inner Membrane ◽  
Isolated Rat Liver ◽  
Isolated Rat

Rat liver mitochondria accumulate protoporphyrin IX from the suspending medium into the inner membrane in parallel with the magnitude of the transmembrane K+ gradient (K+in/K+out). Only protoporphyrin IX taken up in parallel with the transmembrane K+ gradient is available for haem synthesis. Coproporphyrins (isomers I and III) are not taken up by the mitochondria. The results support the suggestion by Elder & Evans [(1978) Biochem. J. 172, 345-347] that the prophyrin to be taken up by the inner mitochondrial membrane belongs to the protoporphyrin(ogen) IX series. Protoporphyrin IX at concentrations above 15 nmol/mg of protein has detrimental effects on the structural and functional integrity of the mitochondria. The relevance of these effects to the hepatic lesion in erythropoietic protoporphyria is discussed.

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