3.4.23.38 proteolytic modification automaturation of proPfPM1 K110pN mutant at pH 4.0-4.5, with reduction of molecular weight by 5 kDa 696329 3.4.23.38 proteolytic modification expression and partial characterization of soluble recombinant PM I from Plasmodium falciparum in which a truncated form of PM I (Lys77P-Leu329) (P indicates a propart residues) is fused to thioredoxin in the pET32b(1) vector, Trx-tPM I and expressed in Escherichia coli Rosetta-gami B (DE3)pLysS. pLysS. The soluble fusion protein is purified from cell culture using a combination of Ni21 affinity and gel filtration chromatography and is capable of autocatalytic activation at pH 4.0–5.5, which occurrs at Leu116P–Ser117P, seven residues upstream of the native cleavage site (Gly123P-Asn1) 682637 3.4.23.38 proteolytic modification plasmepsin I is produced as a precursor. The propart region, about 120 residues, is more than twice as long as those of archetypal zymogens 648190 3.4.23.38 proteolytic modification proplasmepsin maturation appears to require acidic conditions, proplasmepsin maturation may not be autocatalytic in vivo 648184 3.4.23.38 proteolytic modification the proenzyme has an unusually long propart of 125 amino acid residues that mediates type II membrane anchoring of the proenzyme, activation occurs by removal of the propart 648182