Lipid composition of plasma membranes from human leukemic lymphocytes
نویسنده
چکیده
The specific activity of adenosine 5‘-monophosphatase and the concentrations of cholesterol, glucosylceramide, lactosylceramide, and phospholipids were compared in the whole homogenates and in plasma membrane fractions in four preparations of human leukemic lymphocytes taken over a 1-yr period from a patient with chronic lymphocytic leukemia. There was a 69.5-fold enrichment of the specific activity of adenosine 5’”nophosphatase in plasma membrane fractions. This enzyme appeared to be the best plasma membrane marker of all compounds studied. The increase in lactosylceramide concentration in the plasma membranes was 34.4-fold. It was significantly higher than that of glucosylceramide. The. enrichment of glucosylceramide in the plasma membranes was similar to that of cholesterol and total phospholipids. The pattern of individual phospholipids in the plasma membrane fraction, as compared with the whole homogenate, was characterized by a decrease in phosphatidylcholine and an increase in sphingomyelin. Supplementary key words adenosine 5’-monophosphatase . glucosylceramide . lactosylceramide . phospholipids Changes in lipids, especially glycolipids, have been observed during the malignant transformation in several experimental systems (1, 2). Some main characteristics of neoplastic cells such as new antigenic properties or loss of contact inhibition due to modifications in cell surface may be related to these changes (3, 4) because it is assumed that glycolipids are localized primarily if not exclusively in plasma membranes. This assumption, however, is based on studies performed in only a few tissues (5-8). In a large number of cell types this hypothesis still awaits further investigations. A method for isolation of plasma membranes from human leukemic lymphocytes was recently described by this laboratory (9), and the presence of neutral glycolipids in these cells has been previously demonstrated (1 0). The purpose of this study is to compare the distribution of glycolipids and adenosine 5’-monophosphatase (5’-AMPase), a plasma membrane marker, in the whole homogenate and in plasma membranes of human leukemic lymphocytes and to report the lipid composition of these
منابع مشابه
Lipid composition of plasma membranes from human leukemic lymphocytes.
The specific activity of adenosine 5'-monophosphatase and the concentrations of cholesterol, glucosylceramide, lactosylceramide, and phospholipids were compared in the whole homogenates and in plasma membrane fractions in four preparations of human leukemic lymphocytes taken over a 1-yr period from a patient with chronic lymphocytic leukemia. There was a 69.5-fold enrichment of the specific act...
متن کاملComposition and Structure of Cytoplasmic Globules in Leukemic Lymphocytes
By JOHN LASZLO, HERBERT J. GERBER AND JOACHIM R. SOMMER T HE PURPOSE OF THIS PAPER is to describe certain similarities between globules observed in leukemic lymphocytes and globules in plasma cells referred to as Russell bodies. Demonstration of structural and chemical identity of these globules would further strengthen the concept of a transitional pathway between lymphocytes and plasma cells....
متن کاملCharacterization of transformed cells and tumors by proton nuclear magnetic resonance spectroscopy.
Cultured acute lymphoblastic leukemic cells give a well-resolved proton nuclear magnetic resonance spectrum characteristic of isolated plasma membranes. We demonstrate that the signals, in the spectrum of whole cells, arise predominantly from the plasma membrane and that cells transformed by pokeweed mitogen have membranes which are significantly less rigid than are normal human peripheral bloo...
متن کاملComposition and structure of cytoplasmic globules in leukemic lymphocytes.
By JOHN LASZLO, HERBERT J. GERBER AND JOACHIM R. SOMMER T HE PURPOSE OF THIS PAPER is to describe certain similarities between globules observed in leukemic lymphocytes and globules in plasma cells referred to as Russell bodies. Demonstration of structural and chemical identity of these globules would further strengthen the concept of a transitional pathway between lymphocytes and plasma cells....
متن کاملLipid patterns in human leukocytes maintained in long-term culture.
The lipid composition of leukocytes maintained in long-term culture was examined in order to clarify the role of immaturity in previously observed differences between normal mature leukocytes and leukemic cells. Cell cultures derived from three types of leukocytes were examined: normal lymphocytes, Burkitt lymphoma, and chronic myelocytic leukemia. Lipid extracts were analyzed for total lipid w...
متن کامل