Plasmepsin

Plasmepsins are a class of at least 10 enzymes ( and ) produced by the plasmodium parasite. There are ten different isoforms of these proteins and ten genes coding them respectively in plasmodium falciparum (Plm I, II, III, IV, V, VI, VII, IX, X and HAP). It has been suggested that the plasmpesin family is smaller in other human plasmodium species. Expression of Plm I, II, IV, V, IX, X and HAP occurs in erythrocytic cycle, and expression of Plm VI, VII, VIII, occurs in exoerythrocytic cycle. Through their haemoglobin-degrading activity, they are an important cause of symptoms in malaria sufferers. Consequently this family of enzymes is a potential target for antimalarial drugs.the aspartic protease of Plasmodiumspecies are known as Plasmepsins

Plasmepsins are aspartic acid proteases, which means their active site contains two aspartic acid residues. These two aspartic acid residue act respectively as proton donor and proton acceptor, catalysing the hydrolysis of peptide bond in proteins.

There are four types of plasmepsins, closely related but varying in the specificity of cleavage site. Plasmepsins I and II cleave hemoglobin between residues Phenylalanine 33 and Leucine 34 of α-globin subunit.

The name plasmepsin may come from plasmodium (the organism) and pepsin (a common aspartic acid protease with similar molecular structure).

The closest (non-pathogenic) enzymatic equivalent in humans is the beta-secretase enzyme.