- Plasmepsin
Plasmepsins are a class of at least 10 enzymes (EC number|3.4.23.39) produced by the
plasmodium parasite.There are ten different isoforms of these proteins and ten genescoding them respectively in plasmodium falciparum (Plm I, II, III, IV, V, VI, VII, IX, Xand HAP). It has been suggested that the plasmpesin family is smaller in other humanplasmodium species. Expression of Plm I, II, IV, V, IX, X and HAP occurs inerythrocytic cycle, and expression of Plm VI, VII, VIII, occurs in exoerythrocyticcycle. Through their haemoglobin-degrading activity, they are an important cause of symptoms inmalaria sufferers. This family of enzymes is a potential target for antimalarial drugs.the aspartic protease of "Plasmodium"species are known as PlasmepsinsPlasmepsins are
aspartic acid proteases , which means theiractive site contains twoaspartic acid residues.These twoaspartic acid residue act respectively as proton donor and proton acceptor, catalysing the hydrolysis ofpeptide bond inproteins .There are four types of plasmepsins, closely related but varying in the specificity of cleavage site.Plasmepsins I and II cleave
hemoglobin between residuesPhenylalanine 33 andLeucine 34 of α-globin subunit.The name "plasmepsin" may come from "plasmodium" (the organism) and "
pepsin " (a commonaspartic acid protease with similar molecular structure).External links
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