Aljoša BAVEC*, Aleš PODGORNIK** and Matjaž ZORKO*
*Institute of Biochemistry, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
**BIA Separations d.o.o., Ljubljana, Slovenia
Membranes from porcine brain bind relatively large quantities of guanosine 5’-(3-0-thio) triphosphate (GTP?S), a poorly-hydrolysable analogue of GTP. Chromatography of solubilized proteins with 1% Sodium cholate using CIM? DEAE column (Convective Interaction Media) revealed two fractions reach in GTP?S binding proteins. In reduced SDS-PAGE analysis only these two fractions showed a protein band with molecular mass 42 kDa which corresponded to ? subunits Gs, Gi or G11. Comparison between CIM? DEAE and traditional DEAE-Sephacel methods showed that membrane bound heterotrimeric G-proteins might be isolated by HPLC using CIM? supports on second or minute time scale.