%O Admin megjegyzÊs-24720161 #JournalID1# Name: J LABELLED COMPD RAD ISSN: 0362-4803 #JournalID2# %D 2015 %I szte %P 7-13 %T Tritium labelling of a cholesterol amphiphile designed for cell membrane anchoring of proteins. %V 58 %L publicatio16996 %N 1 %R MTMT:2824242 10.1002/jlcr.3254 %X Cell membrane association of proteins can be achieved by the addition of lipid moieties to the polypeptide chain, and such lipid-modified proteins have important biological functions. A class of cell surface proteins contains a complex glycosylphosphatidylinositol (GPI) glycolipid at the C-terminus, and they are accumulated in cholesterol-rich membrane microdomains, that is, lipid rafts. Semisynthetic lipoproteins prepared from recombinant proteins and designed lipids are valuable probes and model systems of the membrane-associated proteins. Because GPI-anchored proteins can be reinserted into the cell membrane with the retention of the biological function, they are appropriate candidates for preparing models via reduction of the structural complexity. A synthetic headgroup was added to the 3beta-hydroxyl group of cholesterol, an essential lipid component of rafts, and the resulting cholesterol derivative was used as a simplified GPI mimetic. In order to quantitate the membrane integrated GPI mimetic after the exogenous addition to live cells, a tritium labelled cholesterol anchor was prepared. The radioactive label was introduced into the headgroup, and the radiolabelled GPI mimetic anchor was obtained with a specific activity of 1.37 TBq/mmol. The headgroup labelled cholesterol derivative was applied to demonstrate the sensitive detection of the cell membrane association of the anchor under in vivo conditions. %J JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS %A Schäfer Balåzs %A Orbån Erika %A Kele Zoltån %A TÜmbÜly Csaba