scholarly journals Membrane-bound redox proteins of the murine Friend virus-induced erythroleukemia cell.

1979 ◽  
Vol 83 (1) ◽  
pp. 231-239 ◽  
Author(s):  
S R Slaughter ◽  
D E Hultquist
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome C ◽  
Dimethyl Sulfoxide ◽  
Reductase Activity ◽  
Cytochrome B5 ◽  
Erythroid Cells ◽  
Friend Virus ◽  
Cytochrome C Reductase ◽  
Membrane Bound ◽  
Nadh Cytochrome

We have obtained and studied a 105,000-g pellet from T-3-Cl-2 cells, a cloned line of Friend virus-induced erythroleukemia cells. By difference spectrophotometry, the pellet was shown to contain cytochrome b5 and cytochrome P-450, hemeproteins that have been shown to participate in electron-transport reactions of endoplasmic reticulum and other membranous fractions of various tissues. The pellet also possesses NADH-cytochrome c reductase activity which is inhibited by anti-cytochrome b5 gamma-globulin, indicating the presence of cytochrome b5 reductase. This is the first demonstration of membrane-bound forms of these redox proteins in erythroid cells. Dimethyl sulfoxide-treated T-3-Cl-2 cells were also shown to possess membrane-bound cytochrome b5 and NADH-cytochrome c reductase activity. We failed to detect soluble cytochrome b5 in the 105,000-g supernatant fraction from homogenates of untreated or dimethyl sulfoxide-treated T-3-Cl-2 cells. In contrast, erythrocytes obtained from mouse blood were shown to possess soluble cytochrome b5 but no membrane-bound form of this protein. These findings are supportive of our hypothesis that soluble cytochrome b5 of erythrocytes is derived from endoplasmic reticulum or some other membrane structure of immature erythroid cells during cell maturation.

scholarly journals PRODUCTION OF MEMBRANE WHORLS IN RAT LIVER BY SOME INHIBITORS OF PROTEIN SYNTHESIS

1974 ◽  
Vol 62 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Kou M. Hwang ◽  
Linda C. Yang ◽  
Christine K. Carrico ◽  
Rose A. Schulz ◽  
John B. Schenkman ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Synthesis ◽  
Cytochrome C ◽  
Peptide Synthesis ◽  
Reductase Activity ◽  
Cytochrome C Reductase ◽  
Nadph Cytochrome ◽  
Nascent Peptide ◽  
Membrane Bound ◽  
Nadph Cytochrome C Reductase

Inhibitors of protein synthesis capable of differential effects on nascent peptide synthesis on membrane-bound and free polyribosomes were employed to investigate the structure and function of cellular membranes of liver. The formation of membranous whorls in the cytoplasm and distension of nuclear membranes were induced by inhibitors of protein synthesis (i.e., cycloheximide and emetine) which predominantly interfere with nascent peptide synthesis on membrane-bound polyribosomes in situ. Other inhibitors of protein synthesis such as puromycin and fusidic acid, which inhibit nascent peptide synthesis on both free and membrane-bound polyribosomes, and chloramphenicol, which inhibits mitochondrial protein synthesis, did not induce these alterations. Cycloheximide, puromycin, and chloramphenicol produce some common cellular lesions as reflected by similar alterations in morphology, such as swelling of mitochondria, degranulation of rough endoplasmic reticulum, and aggregation of free ribosomes. The process of whorl formation in the cytoplasm, the incorporation of [3H]leucine and of [3H]choline into endoplasmic reticulum and the total NADPH-cytochrome c reductase activity of the endoplasmic reticulum were determined. During maximum formation of membranous whorls, [3H]leucine incorporation into cytoplasmic membranes was inhibited, while [3H]choline incorporation into these structures was increased; maximum inhibition of protein synthesis and stimulation of choline incorporation into endoplasmic reticulum, however, preceded whorl formation. Cycloheximide decreased the activity of NADPH-cytochrome c reductase of rough endoplasmic reticulum, but increased NADPH-cytochrome c reductase activity of smooth endoplasmic reticulum. In addition, cycloheximide decreased the content of hemoprotein in both the microsomal and mitochondrial fractions of rat liver, and the activities of mixed function oxidase and of oxidative phosphorylation were impaired to different degrees. Succinate-stimulated microsomal oxidation was also inhibited. The possible mechanisms involved in the formation of membranous whorls, as well as their functions, are discussed.

scholarly journals ENDOPLASMIC RETICULUM AS THE SITE OF LECITHIN FORMATION IN CASTOR BEAN ENDOSPERM

1973 ◽  
Vol 57 (3) ◽  
pp. 659-667 ◽  
Author(s):  
J. M. Lord ◽  
T. Kagawa ◽  
T. S. Moore ◽  
H. Beevers
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome C ◽  
Electron Micrographs ◽  
Castor Bean ◽  
Cytochrome C Reductase ◽  
Diaphorase Activity ◽  
Membrane Bound ◽  
Typical Appearance ◽  
Nadh Cytochrome ◽  
Nadph Cytochrome C Reductase

The properties of a discrete membranous fraction isolated on sucrose gradients from castor bean endosperm have been examined. This fraction was previously shown to be the exclusive site of phosphorylcholine-glyceride transferase. The distribution of NADPH-cytochrome c reductase and antimycin insensitive NADH-cytochrome c reductase across the gradient followed closely that of the phosphorylcholine-glyceride transferase. This fraction also had NADH diaphorase activity and contained cytochromes b5 and P 450. On sucrose gradients containing 1 mM EDTA this fraction had a mean isopycnic density of 1.12 g/cm3 and sedimented separately from the ribosomes; electron micrographs showed that it was comprised of smooth membranes. When magnesium was included in the gradients to prevent the dissociation of membrane-bound ribosomes, the isopycnic density of the membrane fraction with its associated enzymes was increased to 1.16 g/cm3 and under these conditions the electron micrographs showed that the membranes had the typical appearance of rough endoplasmic reticulum. Together these data show that the endoplasmic reticulum is the exclusive site of lecithin formation in the castor bean endosperm and establish a central role for this cytoplasmic component in the biogenesis of cell membranes.

The behavior of cytoplasmic membranes in Phaseolus vulgaris cotyledons during germination

1974 ◽  
Vol 52 (3) ◽  
pp. 535-541 ◽  
Author(s):  
J. E. Thompson
Keyword(s):  
Cytochrome C ◽  
Reductase Activity ◽  
Molecular Complexes ◽  
Cytochrome C Reductase ◽  
Membrane Structure And Function ◽  
Cytoplasmic Membranes ◽  
Microsomal Membranes ◽  
Membrane Bound ◽  
Nadh Cytochrome ◽  
And Function

Information about the effects of germination on cytoplasmic membranes of cotyledons has been obtained by examining selected properties of smooth microsomes purified from cotyledon tissue at various stages of germination. The microsomal membranes contained rotenone-insensitive NADH – cytochrome c reductase (EC. 1.6.99.3) and NADPH – cytochrome c reductase (EC. 1.6.99.1). Measurements of these enzymes in smooth microsomal fractions isolated from various ages of cotyledon tissue revealed that their activities markedly decrease during the late stages of germination, coincident with onset of cotyledon senescence. This decrease is closely paralleled by a corresponding decline in total levels of the enzymes in the cotyledons during the same period, and has been interpreted as reflecting deterioration of cytoplasmic membrane structure and function concurrent with the progression of senescence. The membrane-bound cytochrome c reductase activity does not appear to be solubilized as a result of this deterioration. Furthermore, the protein:phospholipid ratios for the smooth microsomal preparations remain essentially unchanged during germination. This suggests that the macro-molecular complexes of membranes disaggregate more or less spontaneously during senescence and that in the process, the cytochrome c reductases are inactivated.

Endoplasmic reticulum membrane isolated from small-intestinal epithelial cells: enzyme and protein components

1981 ◽  
Vol 52 (1) ◽  
pp. 215-222
Author(s):  
M. Fujita ◽  
H. Ohta ◽  
T. Uezato
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Cytochrome C ◽  
Endoplasmic Reticulum Membrane ◽  
Dependent Manner ◽  
Cytochrome C Reductase ◽  
Basolateral Membranes ◽  
Nadh Cytochrome ◽  
Protein Components ◽  
A Minor

Endoplasmic reticulum membrane-rich fraction was obtained by subfractionation of the light microsomes from mouse jejunal mucosal epithelial cells. It was marked by high glucose-6-phosphatase, NADPH-cytochrome c reductase, and NADH-cytochrome c reductase activities and low Na+,K+-ATPase activity. The enrichment of Na+,K+-ATPase was 180-fold higher in the basolateral membranes than in the endoplasmic reticulum membrane-rich fraction relative to glucose-6-phosphatase. The protein peak that was phosphorylated in a Na-dependent manner was prominent in the basolateral membranes while it was a minor peak in the endoplasmic reticulum membrane-rich fraction. Under the electron microscope the fraction was seen to be composed of homogeneous small vesicles with thin smooth membranes.

Brain Regional Analysis of NADH-Cytochrome C Reductase Activity in Alzheimerʼs Disease

1990 ◽  
Vol 49 (3) ◽  
pp. 206-214 ◽  
Author(s):  
GEORGE S. ZUBENKO ◽  
JOHN MOOSSY ◽  
DIANA CLAASSEN ◽  
A. Julio Martinez ◽  
GUTTI R. RAO
Keyword(s):  
Cytochrome C ◽  
Reductase Activity ◽  
Regional Analysis ◽  
Cytochrome C Reductase ◽  
Nadh Cytochrome

scholarly journals Structural and functional relationships of enzyme activities induced by nitrate in barley

1970 ◽  
Vol 119 (4) ◽  
pp. 715-725 ◽  
Author(s):  
John L. Wray ◽  
Philip Filner
Keyword(s):  
Cytochrome C ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Bottom Layer ◽  
Sucrose Density Gradient ◽  
Enzyme Complex ◽  
Cytochrome C Reductase ◽  
Functional Relationships ◽  
Nadh Cytochrome

1. Nitrate induces the development of NADH-nitrate reductase (EC 1.6.6.1), FMNH2–nitrate reductase and NADH–cytochrome c reductase activities in barley shoots. 2. Sucrose-density-gradient analysis shows one band of NADH–nitrate reductase (8S), one band of FMNH2–nitrate reductase activity (8S) and three bands of NADH–cytochrome c reductase activity (bottom layer, 8S and 3.7S). Both 8S and 3.7S NADH–cytochrome c reductase activities are inducible by nitrate, but the induction of the 8S band is much more marked. 3. The 8S NADH–cytochrome c reductase band co-sediments with both NADH–nitrate reductase activity and FMNH2–nitrate reductase activity. Nitrite reductase activity (4.6S) did not coincide with the activity of either the 8S or the 3.7S NADH–cytochrome c reductase. 4. FMNH2–nitrate reductase activity is more stable (t½ 12.5min) than either NADH–nitrate reductase activity (t½ 0.5min) or total NADH–cytochrome c reductase activity (t½ 1.5min) at 45°C. 5. NADH–cytochrome c reductase and NADH–nitrate reductase activities are more sensitive to p-chloromercuribenzoate than is FMNH2–nitrate reductase activity. 6. Tungstate prevents the formation of NADH–nitrate reductase and FMNH2–nitrate reductase activities, but it causes superinduction of NADH–cytochrome c reductase activity. Molybdate overcomes the effects of tungstate. 7. The same three bands (bottom layer, 8S and 3.7S) of NADH–cytochrome c reductase activity are observed irrespective of whether induction is carried out in the presence or absence of tungstate, but only the activities in the 8S and 3.7S bands are increased. 8. The results support the idea that NADH–nitrate reductase, FMNH2–nitrate reductase and NADH–cytochrome c reductase are activities of the same enzyme complex, and that in the presence of tungstate the 8S enzyme complex is formed but is functional only with respect to NADH–cytochrome c reductase activity.

scholarly journals Inhibition and inactivation of NADH-cytochrome c reductase activity of bovine heart submitochondrial particles by the iron(III)-adriamycin complex

1990 ◽  
Vol 265 (3) ◽  
pp. 865-870 ◽  
Author(s):  
B B Hasinoff
Keyword(s):  
Cytochrome C ◽  
Reductase Activity ◽  
Inner Mitochondrial Membrane ◽  
Submitochondrial Particles ◽  
Cytochrome C Reductase ◽  
Fast Phase ◽  
Bovine Heart ◽  
Direct Binding ◽  
Nadh Cytochrome

The NADH-cytochrome c reductase activity of bovine heart submitochondrial particles was found to be slowly (half-time of 16 min) and progressively lost upon incubation with the Fe2(+)-adriamycin complex. In addition to this slow progressive inactivation seen on incubation, a reversible fast phase of inhibition was also seen. However, if EDTA was added to the incubation mixture within 15 s, the slow progressive loss in activity was largely preventable. Separate experiments indicated that EDTA removed about one-half of the iron from the Fe2(+)-adriamycin complex in about 40 s. These results indicated the requirement for iron for the inactivation process. Since the Vmax. for the fast phase of inhibition was decreased by the inhibitor, the inhibition pattern was similar to that seen for uncompetitive or mixed-type inhibition. The direct binding of both Fe3(+)-adriamycin and adriamycin to submitochondrial particles was also demonstrated, with the Fe3(+)-adriamycin complex binding 8 times more strongly than adriamycin. Thus binding of Fe3(+)-adriamycin to the enzyme or to the inner mitochondrial membrane with subsequent generation of oxy radicals in situ is a possible mechanism for the Fe3(+)-adriamycin-induced inactivation of respiratory enzyme activity.

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