To provide a protein (namely a protein involving inhibition of malaria proliferation) having high affinity for rhodacyanine which is a medicine inhibiting proliferation of malaria protozoan (Plasmodium sp.) parasitized on erythrocyte and to provide a method for isolating the protein and to provide a gene encoding the protein involving inhibition of malaria proliferation and to provide a method for screening an antimalarial therapeutic and prophylactic agent targeting the protein involving inhibition of the malaria proliferation.

Affinity gel containing the rhodacyanine dye as a ligand is prepared and a protein mixture derived from malaria protozoan is absorbed into the affinity gel and a target protein closely related to expression of antimalarial activity is separated by utilizing the difference of affinity of each protein for the affinity gel.