Lentil Lectin Enriched Microsomes from the Plasma Membrane of the Human B-Lymphocyte Cell Line H2LCL Carry a Heavy Load of Type-1 Porin

• Published in: Biological chemistry Vol. 379; no. 12; pp. 1419 - 1426
• Main Authors: Eben-Brunnen, Jana, Reymann, Susanne, Awni, Lewa A., Cole, Thomas, Hellmann, Thea, Hellmann, Klaus P., Paetzold, Gabriele, Kleineke, Jochen, Thinnes, Friedrich P., Götz, Hilde, Hilschmann, Norbert
• Format: Journal Article
• Language: English
• Published: Berlin, New York Walter de Gruyter, Berlin / New York 01.12.1998
• Subjects: B-Lymphocytes - metabolism; Blotting, Western; Cell Compartmentation; Cell Line, Transformed; Chromatography, Affinity; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Humans; Lectins - administration & dosage; Microsomes - metabolism; Plant Lectins; Porins - metabolism
• ISSN: 1431-6730; 1437-4315
• DOI: 10.1515/bchm.1998.379.12.1419

Using an established biochemical approach, five subcellular fractions of human B lymphocytes were prepared by differential centrifugation. Crude membranes were passed over a lentil lectin column to enrich carbohydrate-coated cell surface microsomes. The lectin-bound fraction contained a high amount of plasma membrane-derived microsomes as indicated by cell surface markers. All subcellular fractions in Western blots proved to contain distinct but variable amounts of porin. There was a strong increase in porin content from crude membranes to plasma membrane-derived vesicles. The porin content of this fraction appeared to be higher than that of mitochondria. In the final step the plasma membrane-derived microsome fraction proved to be devoid of contamination by outer mitochondrial membranes, as revealed by antibodies against the established markers MAO B and Tom20 applied in Western blots. These data prove the extramitochondrial expression of human type-1 porin/ type-1 VDAC.