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S Fleischer

Publications and source records attributed to S Fleischer.

283 records · Page 16Linked to original sources
PubMed1967

Fine structure of lipid-depleted mitochondria.

The fine structure of mitochondria and submitochondrial vesicles depleted of their lipid by extraction with aqueous acetone was studied. Thin sections of mitochondrial membranes depleted of more than 95% of their lipid retained the unit membrane structure. Densitometer tracings of the electron micrographs showed that the unit membrane of extracted mitochondria was, on the average, wider than that of unextracted controls and showed a greater variation in width. The outer membrane was lost in mitochondria from which 80-95% of the lipids was extracted. Inner membrane particles were present on submitochondrial vesicles depleted of up to 85% of their lipids. However, when more than 95% of the lipid was removed, few, if any, particles remained attached to the membranes but many particles were found unattached in the background. When lipid was restored to lipid-deficient preparations, the mitochondrial membranes were found to be devoid of inner membrane particles but were fully active with respect to succinate-cytochrome c reductase activity.

Animals↗
PubMed1967

Lipid composition of mitochondria from bovine heart, liver, and kidney.

Highly purified preparations of mitochondria from bovine heart, liver, and kidney were isolated and characterized by electron microscopy, oxidative phosphorylation ability, cytochrome c reductase activity, and cytochrome content. Components of lipid extracts of the preparations were determined by thin-layer chromatography, diethylaminoethyl-cellulose column chromatography, and spectrophotometric procedures. The major phospholipids were identified by their chromatographic behavior, IR spectrometry, and paper chromatography of their hydrolysis products. The lipid content of the mitochondria paralleled that of the components of the electron transfer chain, heart mitochondria being richest and liver mitochondria poorest in lipid. Heart mitochondria contain equal concentrations of coenzyme Q and cholesterol (1%); the highest cholesterol content (4.7%) was found in mitochondria from kidney. The phospholipids of mitochondria from the three organs were qualitatively and quantitatively very similar. The major polar lipid components (cardiolipin, choline glycerophosphatides, and ethanolamine glycerophosphatides) were present in a molar ratio of 1:4:4. It is suggested that mitochondria from different sources contain characteristic lipids, mainly phospholipids, of which cardiolipin is particularly diagnostic of the source of the mitochondria.

Animals↗
PubMedDate not supplied

Lipid composition of sarcoplasmic reticulum from mice with muscular dystrophy.

We have recently reported on the isolation and characterization of sarcoplasmic reticulum (SR) from normal and dystrophic mice. These purified fractions were similar in functional characteristics. We now present an analysis of the lipids in our purified SR. The lipids were generally found to be similar. Most of the differences found between the two preparations were consistent with a somewhat greater surface membrane contamination in SR fractions from dystrophic mice. This was so with respect to cholesterol content and fatty acid composition. A small decrease, however, in content of phosphatidylcholine was observed in the dystrophic SR fractions. Fluorescence polarization studies using the probe 1,6-diphenyl-1,3,5-hexatriene in sarcoplasmic reticulum membranes over the temperature range 3 to 38 C showed slightly greater anisotropy in the dystrophic fractions, which is also consistent with a greater contamination of this fraction by surface membrane elements (sarcolemma and transverse tubule).

Animals↗
PubMedDate not supplied

Phospholipase C treatment of mitochondria.

Heavy beef heart mitochondria depleted of phospholipids by treatment with phospholipase C followed by removal of the by products by lipase treatment or sonication in pentane were analyzed by electron microscopy, chemical analysis and assays of enzymatic activities. The results indicate that diglycerides are present after phospholipase C treatment and are inhibitors of NADH-cytochrome c reductase. After removal of diglycerides with lipase treatment, a phospholipid requirement for NADH-cytochrome c reductase could be demonstrated.

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