id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-281815-zvs5qe8x	Subramanian, Shoba	Hemoglobin Cleavage Site-Specificity of the Plasmodium falciparum Cysteine Proteases Falcipain-2 and Falcipain-3	2009-04-09		.txt	text/plain	5953	267	45	The Plasmodium falciparum cysteine proteases falcipain-2 and falcipain-3 degrade host hemoglobin to provide free amino acids for parasite protein synthesis. Treatment of erythrocytic parasites with cysteine protease inhibitors or disruption of the falcipain-2 gene results in accumulation of undegraded hemoglobin in the food vacuole, confirming a role for this enzyme in hemoglobin hydrolysis [6, 10] . To better characterize the roles of falcipain-2 and falcipain-3, we evaluated activities of these proteases against a library of small peptide substrates, a series of larger peptides spanning the sequences of a and b globin, and intact human hemoglobin. Falcipain-2 and falcipain-3 demonstrated a marked preference for cleavage of small peptide substrates with P 2 Leu, but the enzymes showed less specificity against larger peptides and intact hemoglobin, with hydrolysis at multiple sites. Despite the presence of multiple proteases in the food vacuole, it is noteworthy that treatment of cultured parasites with specific inhibitors of cysteine proteases fully blocked the hydrolysis of hemoglobin, highlighting the key role for the falcipains in this process [22] .	./cache/cord-281815-zvs5qe8x.txt	./txt/cord-281815-zvs5qe8x.txt