1. Hydrophobic and hydrophilic radio-iodination, crosslinking, and differential extraction of cell surface proteins in Paramecium tetraurelia cells.
- Author
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Flötenmeyer, M., Momayezi, M., Plattner, H., and Flötenmeyer, M
- Abstract
We combined widely different biochemical methods to analyze proteins of the cell surface of P. tetraurelia since so far one can isolate only a subfraction of cell membrane vesicles enriched in the GPI-anchored surface antigens ("immoblization" or "i-AGs"). We also found that i-AGs may undergo partial degradation by endogenous proteases. Genuine intrinsic membrane proteins were recognized particularly with lipophilic 5-[(125)I]-iodonaphthalene-1-azide (INA) labeling which reportedly "sees" integral proteins and cytoplasmic cell membrane-associated proteins. With INA (+DTT), bands of =55 kDa were similar as with hydrophilic iodogen (+DTT), but instead of large size bands including i-AGs, a group of 122, 104 and 94 kDa appeared. Several bands of the non i-AG type are compatible with integral (possibly oligomeric) or associated proteins of the cell membrane of established molecular identity, as we discuss. In summary, we can discriminate between i-AGs and some functionally important minor cell membrane components. Our methodical approach might be relevant also for an analysis of some related protozoan parasites. [ABSTRACT FROM AUTHOR]
- Published
- 1999
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