ANTIPEPTIDE ANTIBODIES TO P-GLYCOPROTEIN - HOW EFFECTIVE

Antibodies were produced in rabbits against synthetic peptides coverin g the large majority of extracellular loops of P-glycoprotein, a membr ane-associated protein which is responsible for increased resistance o f cells to cytotoxic drugs. Notwithstanding all six antibodies exhibit ed high affinity for the peptides, and were able to recognize in ELISA trace amounts of the synthetic fragments, the binding to living cells expressing P170 was scarce and none of them was apparently able to di scriminate with certainty sensitive from resistant cells. The possible reasons for this low activity are discussed.