Discontinuities in the arrhenius plots of mitochondrial membrane-bound enzyme systems from a poikilotherm: Acclimation temperature of carp affects transition temperatures

1976 ◽  
Vol 110 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Ekkehart Wodtke
Keyword(s):  
Mitochondrial Membrane ◽  
Acclimation Temperature ◽  
Transition Temperatures ◽  
Arrhenius Plots ◽  
Enzyme Systems ◽  
Membrane Bound

MITOCHONDRIAL MEMBRANE-BOUND STEROID HYDROXYLATING SYSTEMS: STRUCTURE AND FUNCTIONS

1980 ◽  
pp. 131-134
Author(s):  
A.A. Akhrem ◽  
V.N. Lapko ◽  
A.G. Lapko ◽  
S.P. Martsev ◽  
V.M. Shkumatov ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Membrane Bound ◽  
Structure And Functions

scholarly journals Molecular mechanism of mitochondrial phosphatidate transfer by Ups1

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Jiuwei Lu ◽  
Chun Chan ◽  
Leiye Yu ◽  
Jun Fan ◽  
Fei Sun ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Mitochondrial Membrane ◽  
Outer Mitochondrial Membrane ◽  
Mitochondrial Membranes ◽  
Inner Mitochondrial Membrane ◽  
Membrane Interaction ◽  
Detailed Mechanism ◽  
Physiological Regulator ◽  
Membrane Bound ◽  
Dynamics Simulations

AbstractCardiolipin, an essential mitochondrial physiological regulator, is synthesized from phosphatidic acid (PA) in the inner mitochondrial membrane (IMM). PA is synthesized in the endoplasmic reticulum and transferred to the IMM via the outer mitochondrial membrane (OMM) under mediation by the Ups1/Mdm35 protein family. Despite the availability of numerous crystal structures, the detailed mechanism underlying PA transfer between mitochondrial membranes remains unclear. Here, a model of Ups1/Mdm35-membrane interaction is established using combined crystallographic data, all-atom molecular dynamics simulations, extensive structural comparisons, and biophysical assays. The α2-loop, L2-loop, and α3 helix of Ups1 mediate membrane interactions. Moreover, non-complexed Ups1 on membranes is found to be a key transition state for PA transfer. The membrane-bound non-complexed Ups1/ membrane-bound Ups1 ratio, which can be regulated by environmental pH, is inversely correlated with the PA transfer activity of Ups1/Mdm35. These results demonstrate a new model of the fine conformational changes of Ups1/Mdm35 during PA transfer.

Tween-20 Activates and Solubilizes the Mitochondrial Membrane-bound, Calmodulin Dependent NAD + Kinase of Avena sativa L.

2001 ◽  
Vol 182 (2) ◽  
pp. 135-146 ◽  
Author(s):  
M.-A. Pou de Crescenzo ◽  
S. Gallais ◽  
A. Léon ◽  
D.L. Laval-Martin
Keyword(s):  
Avena Sativa ◽  
Mitochondrial Membrane ◽  
Tween 20 ◽  
Nad Kinase ◽  
Membrane Bound

Two Forms of a Mitochondrial Endonuclease in Neurospora crassa

1975 ◽  
Vol 53 (7) ◽  
pp. 823-825 ◽  
Author(s):  
Charles E. Martin ◽  
Robert P. Wagner
Keyword(s):  
Molecular Weight ◽  
Neurospora Crassa ◽  
Mitochondrial Membrane ◽  
Nuclease Activity ◽  
Inner Mitochondrial Membrane ◽  
Detergent Treatment ◽  
Approximate Molecular Weight ◽  
Membrane Bound

Mitochondrial nuclease activity in Neurospora crassa occurs in membrane-bound and soluble forms in approximately equal proportions. These activities apparently are due to the same enzyme, which has an approximate molecular weight of 120 000. A portion of the insoluble enzyme appears to be associated with the inner mitochondrial membrane and is resistant to solubilization by detergent treatment as well as by physical disruption methods.

Drosophila Mitochondrial Membrane‐bound Tafazzin Protein Is A Transacylase

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Yang Xu ◽  
Mindong Ren ◽  
Ashim Malhotra ◽  
Louis Lee ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Membrane Bound

scholarly journals Membrane-lipid unsaturation and mitochondrial function in Saacharomyces cerevisiae

1975 ◽  
Vol 146 (2) ◽  
pp. 409-416 ◽  
Author(s):  
K Watson ◽  
R L Houghton ◽  
E Bertoli ◽  
D E Griffiths
Keyword(s):  
Fatty Acid ◽  
Unsaturated Fatty Acid ◽  
Mitochondrial Membrane ◽  
Membrane Lipids ◽  
Membrane Lipid ◽  
Mitochondrial Atpase ◽  
Degree Of Unsaturation ◽  
Membrane Bound ◽  
Lipid Unsaturation ◽  
Membrane Bound Enzymes

The lipid composition of yeast cells was manipulated by the use of an unsaturated fatty acid auxotroph of Saccharomyces cerevisiae. There was a 2-3-fold decrease in the concentration of cytochromes a+a3 when the unsaturated fatty acid content of the cells was decreased from 60-70% of the total fatty acid to 20-30%. The amounts of cytochromes b and c were also decreased under these conditions, but to a lesser extent. Further lipid depletion, to proportions of less than 20% unsaturated fatty acid, led to a dramatic decrease in the content of all cytochromes, particularly cytochromes a+a3. The ATPase (adenosine triphosphatase), succinate oxidase and NADH oxidase activities of the isolated mitochondria also varied with the degree of unsaturation of the membrane lipids. The lower the percentage of unsaturated fatty acid, the lower was the enzymic activity. Inhibition of mitochondrial ATPase by oligomycin, on the other hand, was not markedly influenced by the membrane-lipid unsaturation. Npn-linear Arrenius plots of mitochondrial membrane-bound enzymes showed transition temperatures that were dependent on the degree of membrane-lipid unsaturation. The greater the degree of lipid unsaturation, the lower was the transition temperature. It was concluded that the degree of unsaturation of the membrane lipids plays an important role in determining the properties of mitochondrial membrane-bound enzymes.

scholarly journals KCl-Dependent Release of Mitochondrial Membrane-Bound Arginase Appears to Be a Novel Variant of Arginase-II

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Mishra Suman ◽  
Mishra Rajnikant
Keyword(s):  
Outer Membrane ◽  
Mitochondrial Membrane ◽  
Functional Anatomy ◽  
Mitochondrial Enzymes ◽  
Novel Variant ◽  
Immunological Surveillance ◽  
Membrane Bound ◽  
Arginase Ii ◽  
Arginase I ◽  
Homogenization Medium

Arginase regulates arginine metabolism, ornithine-urea cycle, and immunological surveillance. Arginase-I is predominant in cytosol, and arginase-II is localised in the mitochondria. A mitochondrial membrane-bound arginase has also been proposed to be adsorbed with outer membrane of mitochondria which gets released by 150 mM potassium chloride (KCl). It is presumed that inclusion of 150 mM KCl in the homogenization medium would not only facilitate release of arginase bound with outer membrane of mitochondria but also affect functional anatomy of mitochondria, mitochondrial enzymes, and proteins. Therefore, it has been intended to characterize KCl-dependent release of mitochondrial membrane-bound arginase from liver of mice. Results provide advancement in the area of arginase biology and suggest that fraction of mitochondrial membrane-bound arginase contains mitochondrial arginase-II and a variant of arginase-II.

scholarly journals THE EFFECT OF SONIC OSCILLATION ON THE STRUCTURE AND FUNCTION OF BEEF HEART MITOCHONDRIA

1964 ◽  
Vol 22 (1) ◽  
pp. 49-62 ◽  
Author(s):  
John T. Stasny ◽  
F. L. Crane
Keyword(s):  
Mitochondrial Membrane ◽  
Enzymatic Activities ◽  
Beef Heart ◽  
Differential Centrifugation ◽  
Electron Microscopic ◽  
Beef Heart Mitochondria ◽  
Sonic Treatment ◽  
Membrane Bound ◽  
And Function ◽  
Cytochrome Content

Sonic treatment of mitochondria from beef heart results in a distribution of variously sized particles which can be fractionated by differential centrifugation. Electron microscopic observations of negatively stained fractions shows the presence of subunits, which are "knob-like" in appearance, attached to the mitochondrial membrane and membrane derivatives. Such subunits are not completely removed from the membrane by 5 minutes of sonic treatment. However, a fraction containing singular subunits of dimensions similar to those of units attached to the mitochondrial membrane has been observed. Enzymatic activities and cytochrome contents were determined for mitochondria and the fractionated, mitochondrial membrane derivatives. A concentration of enzyme activity and cytochrome content was found in fractions sedimented at 35,300 g and 79,420 g via differential centrifugation in 2x distilled water. The fraction with the highest enzymatic activities and cytochrome content, although rich in mitochondrial membrane derivatives, is deficient in membrane-bound subunits. The fraction with the lowest enzymatic activities and cytochrome content resembles detached mitochondrial subunits when examined in the electron microscope. The biochemical data and the electron microscopic observations suggest that the mitochondrial membrane and not the subunits are responsible for electron transport activity.

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