Photoaffinity labeling of chloroquine-binding proteins in Plasmodium falciparum

Abstract

A photoreactive analog of chloroquine, N-(4-(4-diethylamino-1- methylbutylamino)quinolin-6-yl)-4-azido-2-hydroxybenzamide (referred to as ASA-Q), has been synthesized and shown to mimic the action of chloroquine in possessing substantial antimalarial activity against a chloroquine-sensitive strain of Plasmodium falciparum. As for chloroquine, ASA-Q is less effective at killing drug-resistant strains of malaria, and the resistance can be modulated using the reagent verapamil. ASA-Q has been radiolabeled with Na125I and used as a photoaffinity probe for labeling chloroquine-binding proteins in malaria-infected erythrocytes. Two proteins have been identified with apparent molecular masses of 42..