Elevated cholesterol and decreased sterol carrier protein-2 in peroxisomes from AS-30D hepatoma compared to normal rat liver
| Autor: | H.T. Lyons, Scott Tenner, Robert P. Donaldson, R. Chanderbhan, N E Wolins, Gary Fiskum, A. Kharroubi |
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| Rok vydání: | 1991 |
| Předmět: |
Osmotic shock
Immunoblotting Radioimmunoassay Biophysics Biology Cell Fractionation Microbodies Biochemistry chemistry.chemical_compound Liver Neoplasms Experimental Centrifugation Density Gradient Tumor Cells Cultured Animals Molecular Biology Plant Proteins Cholesterol Rats Inbred Strains Metabolism Peroxisome Sterol Rats Sterol carrier protein Liver chemistry Catalase biology.protein Female Carrier Proteins |
| Zdroj: | Archives of Biochemistry and Biophysics. 285:238-245 |
| ISSN: | 0003-9861 |
| DOI: | 10.1016/0003-9861(91)90355-m |
| Popis: | Peroxisomes were isolated from AS-30D hepatoma and compared to normal rat liver cells for the purpose of investigating the cholesterol accumulation in the hepatoma cells. Cholesterol was found to be approximately 10-fold higher relative to protein in AS-30D peroxisomes as compared to peroxisomes from normal liver. The peroxisomes from the hepatoma cells were found to be more stable; catalase was not released from these peroxisomes during isolation or osmotic shock of the peroxisomal fraction. The elevated cholesterol level may stabilize the peroxisomal membrane. Sterol carrier protein-2 (SCP-2) levels were measured using a radioimmunoassay (RIA), which indicated the highest concentration of SCP-2 to be in peroxisomes. Hepatoma peroxisomes had a lower concentration of SCP-2 (2.5 micrograms/mg) than normal liver peroxisomes (8 micrograms/mg). Approximately half of all SCP-2 detected was found to be soluble in both hepatoma and normal rat liver cells. Immunoblots from both rat liver and AS-30D fractions demonstrated the presence of the 14-kDa form of SCP-2. The liver fractions also had a 57-kDa immunoreactive protein, which was barely detectable in the AS-30D fractions. The low abundance of the high molecular weight form of SCP-2 from hepatoma peroxisomes and the lower amounts of SCP-2 detected in the AS-30D peroxisomes may be related to the accumulation of cholesterol in the cells. |
| Databáze: | OpenAIRE |
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