Affinage · Plasmodium

Showing PF3D7_1408000 — PLASMEPSIN II is a gene name.

PMII

PF3D7_1408000 · plasmepsin II

Annotated
2026-09-08
97 papers in source corpus 27 papers cited in narrative 27 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

PMII (PF3D7_1408000) is a food-vacuole aspartic protease of Plasmodium falciparum that initiates hemoglobin catabolism during the intraerythrocytic trophozoite stage (PMID:11782538, PMID:9247924). It is synthesized as a type II integral membrane proenzyme (proplasmepsin II) later in development than plasmepsin I, transported through the secretory pathway to cytostomal vacuoles and carried with hemoglobin substrate to the acidic (pH 5.4-5.5) food vacuole, where it is cleaved to the soluble mature enzyme (PMID:9169469, PMID:14709539, PMID:17696875); PTEX core components interact with PMII and are required for its normal trafficking and for hemoglobin digestion (PMID:37523385). Zymogen activation proceeds primarily through cleavage by falcipain cysteine proteases, with autoprocessing serving as a redundant backup route (PMID:18308731); structurally, the prosegment holds the N-domain shifted away from the catalytic dyad rather than occluding a preformed active site, so low-pH disruption of salt bridges permits assembly of the functional catalytic-aspartate pair (Asp34/Asp214) (PMID:9886289, PMID:9405050). As an endoproteinase, PMII cleaves native hemoglobin into discrete peptides for downstream exopeptidase processing outside the vacuole (PMID:9247924, PMID:15574427), with active-site subsite residues (e.g. Met13, Ile287) governing substrate specificity from the S1 pocket out to distal positions (PMID:10548045, PMID:15574427). In the food vacuole PMII is a member of an ~200-kDa multiprotease complex containing falcipain-2/2', plasmepsin IV, histo-aspartic protease, and heme detoxification protein that couples hemoglobin degradation to hemozoin formation (PMID:23471987). PMII is individually dispensable for viability owing to redundancy among vacuolar plasmepsins, but its loss lengthens doubling time and impairs growth under amino-acid limitation (PMID:15513918). Beyond hemoglobin, recombinant PMII cleaves erythrocyte cytoskeletal proteins (spectrin, actin, protein 4.1) at neutral pH and localizes to the periphery of mature parasites (PMID:10318841). Multiple crystal structures reveal marked interdomain and active-site flexibility that has been exploited for inhibitor design, and HIV-1 protease inhibitors such as lopinavir and ritonavir inhibit PMII and block parasite growth (PMID:8816746, PMID:12614616, PMID:38304146, PMID:15980379). Increased pm2/3 copy number modulates but does not independently confer piperaquine resistance, which requires additional pfcrt mutations (PMID:38912775, PMID:30580023, PMID:40720544).

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 1994 High

    Establishing that PMII is a genuine catalytically active aspartic protease was the first step, distinguishing it functionally from its closest human relative renin.

    Evidence Recombinant expression in E. coli, refolding, and chromogenic peptide hydrolysis assays

    PMID:7925966

    Open questions at the time
    • Physiological substrate not addressed
    • In vivo activation and localization unknown at this stage
  2. 1996 High

    Solving the pepstatin-bound structure and defining kinetic parameters gave the atomic and catalytic framework needed to design selective inhibitors that also kill parasites, validating PMII as a drug target.

    Evidence X-ray crystallography with pepstatin A, structure-based inhibitor design, fluorogenic substrate kinetics with domain-swap mutagenesis, parasite growth inhibition

    PMID:8816746 PMID:8844673

    Open questions at the time
    • Whether inhibitor killing is due specifically to PMII inhibition not established
    • Interdomain flexibility functional consequences unclear
  3. 1997 High

    Biosynthesis, protonation-state, and hemoglobin-cleavage studies together placed PMII in the hemoglobin-degradation pathway and clarified its acidic activity requirements and endoproteinase mode of action.

    Evidence Pulse-chase biosynthesis and inhibitor profiling, isothermal titration calorimetry of pepstatin binding, in vitro hemoglobin digestion with vacuole lysate and mass spectrometry

    PMID:9169469 PMID:9247924 PMID:9405050

    Open questions at the time
    • Identity of the in vivo maturation enzyme unresolved
    • PMII-specific hemoglobin cleavage not separated from other vacuolar proteases in all assays
  4. 1998 Medium

    Comparing HbF and HbA digestion linked PMII substrate preference to a host protective phenotype, showing enzyme-level substrate discrimination has physiological consequences.

    Evidence In vitro recombinant PMII digestion of fetal versus adult hemoglobin

    PMID:9746793

    Open questions at the time
    • Single-lab in vitro comparison
    • Contribution relative to other plasmepsins in vivo not addressed
  5. 1999 High

    The zymogen structure, active-site specificity mapping, and neutral-pH cytoskeletal cleavage collectively defined the activation mechanism, substrate recognition determinants, and a possible second (cytoskeletal) function.

    Evidence X-ray crystallography of proplasmepsin II, chromogenic octapeptide substitution scans with mutagenesis, in vitro cleavage of spectrin/actin/protein 4.1 with mass spectrometry and immunofluorescence

    PMID:10318841 PMID:10548045 PMID:9886289

    Open questions at the time
    • In vivo relevance of neutral-pH cytoskeletal cleavage not established
    • Trigger of the pH-dependent domain shift not experimentally isolated
  6. 2004 High

    Genetic disruption, live-cell trafficking tracing, and extended substrate mapping together established that PMII is dispensable yet growth-promoting, and defined its route to the food vacuole and its distal substrate contacts.

    Evidence Double-crossover gene disruption with growth assays, chromosomal proPMII-GFP with live imaging and immuno-EM, fluorescence-quenched peptide extension kinetics with mutagenesis and native hemoglobin degradation

    PMID:14709539 PMID:15513918 PMID:15574427

    Open questions at the time
    • Molecular basis of redundancy among plasmepsins not dissected
    • Proposed hemoglobin denaturase activity mechanism not fully defined
  7. 2007 Medium

    Using proPMII-GFP as a reporter fixed the food vacuole pH at 5.4-5.5 and excluded cytostomal vesicles as digestion sites, pinning PMII activity to the acidic terminal compartment.

    Evidence proPMII-GFP transfectants, flow cytometry pH measurement, GFP photobleaching, LysoSensor Blue

    PMID:17696875

    Open questions at the time
    • Link from compartment pH to PMII function is inferred
    • No direct in-compartment activity readout
  8. 2008 High

    Identifying falcipains as the primary maturation proteases with autoprocessing as backup explained how the membrane-bound zymogen is converted to soluble enzyme and revealed cross-family redundancy in activation.

    Evidence Cysteine protease inhibitors, fluorescence microscopy of processing, in vitro processing assays

    PMID:18308731

    Open questions at the time
    • Relative in vivo contribution of falcipain cleavage versus autoprocessing under physiological conditions not quantified
  9. 2013 High

    Demonstrating PMII membership in an ~200-kDa multiprotease complex reframed hemoglobin degradation and hemozoin formation as a coordinated assembly rather than the action of isolated enzymes.

    Evidence Reciprocal Co-IP/MS, gel filtration, glycerol gradient cosedimentation, in vitro hemoglobin-to-hemozoin reconstitution

    PMID:23471987

    Open questions at the time
    • Stoichiometry and PMII-specific interaction surfaces within the complex not defined
    • Whether complex assembly is required for PMII activity unresolved
  10. 2024 High

    Later crystal structures with HIV-1 protease inhibitors and copy-number/knockout drug studies refined the inhibitor-binding landscape and clarified PMII's contribution to piperaquine susceptibility as modulatory rather than causal.

    Evidence X-ray crystallography with ritonavir/lopinavir plus enzyme inhibition, genetic cross with 104 progeny and PPQ assays, CRISPR knockouts with hemoglobin digestion analysis, overexpression drug-susceptibility assays

    PMID:12454457 PMID:12614616 PMID:15840589 PMID:15980379 PMID:20043183 PMID:30580023 PMID:38304146 PMID:38912775 PMID:40720544

    Open questions at the time
    • Mechanistic basis by which pm2/3 copy number modulates PPQ susceptibility not resolved
    • Interaction with catestatin only weakly characterized (single lab, partial inhibition)

Open questions

Synthesis pass · forward-looking unresolved questions
  • How PMII's individual dispensability, its role within the multiprotease complex, and its modulation of drug susceptibility integrate at the systems level remains open.
  • The precise molecular link between pm2/3 copy number and piperaquine resistance in the pfcrt-mutant context is undefined
  • The in vivo significance of neutral-pH cytoskeletal cleavage is unestablished
  • The structural basis of PMII's specific contribution to the ~200-kDa complex is unknown

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
CATESTATIN (CHROMOGRANIN A-DERIVED INHIBITORY PEPTIDE, LOW CONFIDENCE) [#25]FALCIPAIN-2/2', PLASMEPSIN IV, HISTO-ASPARTIC PROTEASE, HEME DETOXIFICATION PROTEIN (COMPLEX MEMBERS) [#12]FALCIPAINS (ACTIVATING PROTEASES) [#10]PTEX CORE COMPONENTS (PTEX150) [#21]
Complex memberships
~200-kDa food vacuole multiprotease complex (falcipain-2/2', plasmepsin II, plasmepsin IV, histo-aspartic protease, heme detoxification protein) [#12]

Evidence

Reading pass · 27 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1996 Crystal structure of PMII (plasmepsin II) complexed with pepstatin A was determined, revealing the enzyme as an aspartic protease with two different interdomain conformations in the crystal, indicating remarkable interdomain flexibility. The structure was used to design selective low-molecular-weight inhibitors that inhibit both PMII and P. falciparum growth in culture. X-ray crystallography (crystal structure determination), structure-based inhibitor design, P. falciparum growth inhibition assay Proceedings of the National Academy of Sciences of the United States of America High 8816746
1994 PMII was expressed recombinantly in E. coli, refolded from inclusion bodies, and shown to be an active aspartic protease that hydrolyzes chromogenic peptide substrates. Despite ~35% identity to human renin, PMII was not significantly inhibited by renin inhibitors. Recombinant protein expression, refolding, ion-exchange purification, enzymatic activity assay with chromogenic peptide substrates FEBS letters High 7925966
1997 PMII is synthesized later in parasite development (trophozoite stage) compared to plasmepsin I (ring stage). Both proplasmepsins are type II integral membrane proteins transported through the secretory pathway before cleavage to soluble form. They are not glycosylated in vivo. Proplasmepsin maturation requires acidic conditions and is inhibited by tripeptide aldehydes but not by canonical aspartic or cysteine protease inhibitors, suggesting maturation is not autocatalytic in vivo and may require an unusual processing enzyme. Metabolic labeling, pulse-chase biosynthesis, pharmacological inhibition with protease inhibitors, subcellular fractionation The Journal of biological chemistry High 9169469
1997 PMII cleaves hemoglobin and generates discrete peptide fragments in digestive vacuole lysate, acting as an endoproteinase with cleavage sites averaging 8.4 amino acids apart. No free amino acids were detected, supporting a model where small peptides are transported out of the digestive vacuole for further exopeptidase processing in the cytoplasm. In vitro hemoglobin digestion with digestive vacuole lysate, mass spectrometry identification of cleavage products, colorimetric aminopeptidase assay Molecular and biochemical parasitology Medium 9247924
1999 Crystal structure of the proplasmepsin II zymogen was determined. A large N-domain shift relative to the central and C-domains opens the active site cleft, preventing formation of a functional catalytic dyad. The prosegment acts as a 'harness' keeping domains apart rather than occluding a pre-formed active site (a mechanism distinct from gastric aspartic proteinase zymogens). Disruption of key salt bridges at low pH may trigger activation. X-ray crystallography of proplasmepsin II zymogen Nature structural biology High 9886289
1999 PMII is active at neutral pH (pH 6.8) on erythrocyte membrane skeleton components: recombinant PMII cleaved spectrin (within the SH3 motif), actin, and protein 4.1 from erythrocyte ghosts. Mass spectrometry identified PMII cleavage sites in the spectrin SH3 motif. Confocal immunofluorescence in schizont-infected erythrocytes localized PMII antibody signal to the periphery of mature parasites, suggesting a role in cytoskeletal remodeling in addition to hemoglobin degradation. In vitro cleavage of recombinant SH3 motif and native spectrin by recombinant PMII, mass spectrometry of cleavage products, Western blotting with anti-PMII antibodies, confocal immunofluorescence The Journal of biological chemistry Medium 10318841
1996 Kinetic parameters of PMII were established using a synthetic fluorogenic peptide substrate based on the initial hemoglobin cleavage site. Recombinant PMII behaves similarly to the native enzyme kinetically. A polyproline loop swap experiment showed that this loop does not determine substrate specificity in PMII (unlike its role in renin). Fluorogenic peptide substrate assay, kinetic parameter determination, domain-swap mutagenesis Molecular and biochemical parasitology High 8844673
2002 Genome-wide analysis established that PMII (along with plasmepsin I, IV, and HAP) is expressed during the hemoglobin-degrading intraerythrocytic stage and localizes to the food vacuole, where it functions as an active hemoglobin-degrading protease. Gene expression analysis, immunolocalization, enzymatic activity assays Proceedings of the National Academy of Sciences of the United States of America Medium 11782538
2004 Targeted gene disruption by double crossover homologous recombination showed that PMII is individually dispensable for parasite viability in culture. Parasites with PMII deletion are viable and morphologically normal but exhibit a longer doubling time in rich medium (decreased productive progeny) and slower growth in amino acid-limited medium, indicating functional redundancy among vacuolar plasmepsins with PMII contributing to optimal growth. Targeted gene disruption (double crossover homologous recombination), parasite growth assays in normal and amino acid-limited media, protease inhibitor sensitivity assays The Journal of biological chemistry High 15513918
2004 PMII trafficking to the food vacuole was traced using a chromosomally encoded proPMII-GFP chimera in live parasites. proPMII is transported through the secretory system to cytostomal vacuoles and then carried along with hemoglobin substrate to the food vacuole, where it is proteolytically processed to mature PMII. This pathway was established using GFP fluorescence in live cells, immunoelectron microscopy, and pharmacological inhibitors of trafficking and maturation. Chromosomal proPMII-GFP fusion, live fluorescence microscopy, immunoelectron microscopy, pharmacological inhibitors of trafficking and maturation The Journal of cell biology High 14709539
2008 PMII (and other food vacuole plasmepsins) are activated primarily by the cysteine proteases falcipains, which cleave them from the membrane. If falcipain activity is blocked, PMII can undergo autoprocessing as an alternate activation route, establishing a further level of redundancy between protease families. Chemical biology (cysteine protease inhibitors), cell biology (fluorescence microscopy of processing), enzymology (in vitro processing assays) The Journal of biological chemistry High 18308731
2007 Using proPMII-GFP transfectants and quantitative flow cytometry, the digestive vacuole pH was determined to be 5.4–5.5 (the compartment where PMII is active), with no significant difference between chloroquine-sensitive and -resistant strains. Cytostomal vesicles were found not to be measurably acidic, indicating they are not the site of hemoglobin digestion. proPMII-GFP chimera transfectants, quantitative flow cytometry pH measurement, GFP photobleaching kinetics, LysoSensor Blue accumulation The Biochemical journal Medium 17696875
2013 PMII is a component of an ~200-kDa protein complex in the food vacuole required for hemoglobin degradation and hemozoin formation. The complex contains falcipain 2/2', plasmepsin II, plasmepsin IV, histo-aspartic protease, and heme detoxification protein, as demonstrated by co-immunoprecipitation followed by mass spectrometry, gel filtration co-elution, glycerol gradient cosedimentation, and in vitro protein interaction analyses. Co-immunoprecipitation with mass spectrometry, gel filtration chromatography, glycerol gradient cosedimentation, in vitro protein interaction assays, in vitro hemoglobin-to-hemozoin reconstitution assay Proceedings of the National Academy of Sciences of the United States of America High 23471987
1997 Thermodynamic analysis of pepstatin binding to PMII by isothermal titration calorimetry established the protonation states of the catalytic aspartate residues: Asp34 has a pKa of ~6.5 and Asp214 has a pKa of ~3.0 in the presence of bound ligand, with His164 (pKa ~7.5) also changing protonation on binding. At pH 5.0 (optimum activity), the total charge of the active-site aspartates is -1. Isothermal titration calorimetry, circular dichroism, thermodynamic proton linkage analysis Biochemistry High 9405050
1999 Active site specificity of PMII was mapped using chromogenic octapeptide substrates with systematic substitutions, identifying preferred residues at each subsite (optimal substrate: Lys-Pro-Ile-Leu-Phe*Nph-Ala/Glu-Leu-Lys). Site-directed mutagenesis of Met13, Ser77, and Ile287 showed that Met13Glu and Ile287Glu mutations confer ability to cleave substrates containing Lys residues, identifying these residues as determinants of active site specificity. Chromogenic peptide substrate assays, site-directed mutagenesis of active site residues Protein science High 10548045
2004 PMII has distal substrate interactions extending to the P6 position: N-terminal extension of a fluorescence-quenched octapeptide substrate increases maximal velocity, while concentration-dependent substrate inhibition also appears. Site-directed mutagenesis identified PMII residues that interact with N-terminal amino acids of peptide substrates. These same residues influence PMII degradation of hemoglobin. PMII can degrade native hemoglobin (a substrate for PMII but not for the related mammalian enzyme cathepsin E), suggesting PMII may have a hemoglobin denaturase activity. Fluorescence-quenched peptide substrate kinetics, N-terminal substrate extension assays, site-directed mutagenesis, hemoglobin degradation assays The Journal of biological chemistry High 15574427
2003 Novel crystal structures of uncomplexed PMII (1.9 Å) and PMII in complex with a potent non-peptidic inhibitor (2.7 Å) revealed that the binding cavity is considerably more open than in the pepstatin A complex, accommodating larger heterocyclic groups in P1', P2', and P2 positions. Crystal contacts show extensive interlocking of monomers with >2300 Ų buried at the interface. X-ray crystallography Journal of molecular biology High 12614616
2002 Crystal structures of Ser205 mutant PMII in complex with two hydroxypropylamine transition-state mimetic inhibitors (rs367 and rs370) at 1.8 Å revealed key conserved hydrogen bonds between inhibitor and PMII binding-cavity residues including flap residues Val78 and Ser79, catalytic dyad Asp34 and Asp214, and Ser218 and Gly36. Structures showed unexpected conformational variability of the binding cavity. X-ray crystallography of mutant PMII-inhibitor complexes Acta crystallographica. Section D, Biological crystallography High 12454457
2005 X-ray structure of PMII at 1.6 Å with a potent achiral inhibitor revealed an unprecedented binding orientation in which the inhibitor contacts the catalytic aspartates indirectly via the 'catalytic' water. Major side chain rearrangements in the active site open a new pocket, and a second inhibitor molecule was located in the active site. X-ray crystallography The Journal of biological chemistry High 15840589
1998 Recombinant PMII digests fetal hemoglobin (HbF) only half as well as adult hemoglobin A (HbA) in vitro, providing a molecular mechanism for the protection conferred by HbF against malaria: HbF's resistance to PMII digestion slows parasite growth. In vitro hemoglobin digestion assay with recombinant PMII, comparison of HbF vs HbA substrates Blood Medium 9746793
2005 HIV-1 protease inhibitor lopinavir inhibits PMII at an IC50 of 2.7 μM, and all seven tested HIV-1 protease inhibitors inhibit P. falciparum parasite development in culture at pharmacologically relevant concentrations, suggesting PMII as one of their antimalarial targets. PMII enzyme inhibition assay (IC50 determination), P. falciparum growth inhibition assay Antimicrobial agents and chemotherapy Medium 15980379
2023 PMII interacts with PTEX (Plasmodium translocon of exported proteins) core components, as shown by co-immunoprecipitation. PMII and falcipain 2a were proposed to be translocated via PTEX into the parasitophorous vacuole to reach the cytostome prior to food vacuole entry. Knockdown of PTEX150 perturbed hemoglobin digestion and affected PMII trafficking. Conditional PTEX150 knockdown, co-immunoprecipitation of PMII with PTEX components, transgenic parasite lines, hemoglobin digestion assays PLoS pathogens Medium 37523385
2018 Overexpression of PMII and plasmepsin III in the 3D7 genetic background failed to alter P. falciparum sensitivity to artesunate, chloroquine, or piperaquine by dose-response analysis or piperaquine survival assay, indicating that PMII overexpression alone is not sufficient to confer piperaquine resistance. Transgenic overexpression of PMII/PMIII in 3D7, dose-response drug susceptibility assay, piperaquine survival assay International journal for parasitology. Drugs and drug resistance Medium 30580023
2025 CRISPR-Cas9 knockout of PMII in Cambodian parasites with multiple plasmepsin gene copies increased parasite sensitivity to piperaquine. Parasites with PMII deletions showed slowed hemoglobin digestion. However, protease inhibitors had minimal impact on PPQ susceptibility, and higher plasmepsin copy number parasites did not show significantly increased hemoglobin digestion or different peptide composition or free heme following PPQ treatment compared to wildtype (single copy) parasites. CRISPR-Cas9 gene knockout of PMII and PMIII, piperaquine susceptibility assays, hemoglobin digestion assays, peptide composition analysis PLoS pathogens Medium 40720544
2024 Crystal structures of PMII in complex with HIV-1 protease inhibitors ritonavir and lopinavir were determined. Both drugs interact with PMII via multiple hydrogen bonding and hydrophobic interactions; ritonavir's P4 moiety forms additional interactions compared to lopinavir and exhibits conformational flexibility in a large S4 pocket. Biochemical assays confirmed that ritonavir and lopinavir exhibit the highest inhibition activity against PMII among plasmepsins tested. X-ray crystallography of PMII-drug complexes, enzyme inhibition assays Current research in structural biology High 38304146
2009 Catestatin (a chromogranin A-derived peptide) shows a specific protein-protein interaction with PMII precursor, demonstrated in the presence of parasite-specific lactate dehydrogenase. Catestatin partially inhibits plasmepsin activity in vitro. Protein-protein interaction assay, enzyme inhibition assay Cellular and molecular life sciences Low 20043183
2024 Using a genetic cross between a Cambodian multi-drug resistant isolate (KH004, with multiple pm2/3 copies) and a drug-susceptible Malawian parasite (Mal31, single copy pm2/3), inheritance of increased pm2/3 copy number further decreased PPQ susceptibility but did not confer resistance in the absence of additional pfcrt mutations. This epistasis analysis established that PMII copy number variation modulates but does not independently cause piperaquine resistance. Genetic cross, recovery of 104 recombinant progeny, PPQ survival assay, dose-response area under curve, IC50 determination, competitive fitness assays mBio High 38912775

Source papers

Stage 0 corpus · 97 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2002 Four plasmepsins are active in the Plasmodium falciparum food vacuole, including a protease with an active-site histidine. Proceedings of the National Academy of Sciences of the United States of America 346 11782538
2016 Genetic markers associated with dihydroartemisinin-piperaquine failure in Plasmodium falciparum malaria in Cambodia: a genotype-phenotype association study. The Lancet. Infectious diseases 306 27818095
2001 Aspartic proteases of Plasmodium falciparum and other parasitic protozoa as drug targets. Trends in parasitology 254 11872398
1996 Structure and inhibition of plasmepsin II, a hemoglobin-degrading enzyme from Plasmodium falciparum. Proceedings of the National Academy of Sciences of the United States of America 223 8816746
2004 The role of Plasmodium falciparum food vacuole plasmepsins. The Journal of biological chemistry 157 15513918
2008 Malarial proteases and host cell egress: an 'emerging' cascade. Cellular microbiology 143 18503638
2013 Protein complex directs hemoglobin-to-hemozoin formation in Plasmodium falciparum. Proceedings of the National Academy of Sciences of the United States of America 131 23471987
1999 Potent, low-molecular-weight non-peptide inhibitors of malarial aspartyl protease plasmepsin II. Journal of medicinal chemistry 128 10212129
2006 Plasmepsins as potential targets for new antimalarial therapy. Medicinal research reviews 127 16838300
2004 Trafficking of plasmepsin II to the food vacuole of the malaria parasite Plasmodium falciparum. The Journal of cell biology 122 14709539
2005 Antimalarial activity of human immunodeficiency virus type 1 protease inhibitors. Antimicrobial agents and chemotherapy 111 15980379
2003 Novel uncomplexed and complexed structures of plasmepsin II, an aspartic protease from Plasmodium falciparum. Journal of molecular biology 111 12614616
1998 Antimalarial synergy of cysteine and aspartic protease inhibitors. Antimicrobial agents and chemotherapy 107 9736544
1994 High level expression and characterisation of Plasmepsin II, an aspartic proteinase from Plasmodium falciparum. FEBS letters 105 7925966
2017 Association of a Novel Mutation in the Plasmodium falciparum Chloroquine Resistance Transporter With Decreased Piperaquine Sensitivity. The Journal of infectious diseases 99 28931241
1997 Generation of hemoglobin peptides in the acidic digestive vacuole of Plasmodium falciparum implicates peptide transport in amino acid production. Molecular and biochemical parasitology 99 9247924
2002 New antiinfective and human 5-HT2 receptor binding natural and semisynthetic compounds from the Jamaican sponge Smenospongia aurea. Journal of natural products 97 11975483
2018 Plasmepsin II-III copy number accounts for bimodal piperaquine resistance among Cambodian Plasmodium falciparum. Nature communications 96 29720620
1997 Biosynthesis and maturation of the malaria aspartic hemoglobinases plasmepsins I and II. The Journal of biological chemistry 96 9169469
2008 Plasmodium food vacuole plasmepsins are activated by falcipains. The Journal of biological chemistry 92 18308731
1997 Expression and characterisation of plasmepsin I from Plasmodium falciparum. European journal of biochemistry 91 9119023
2003 High-affinity inhibition of a family of Plasmodium falciparum proteases by a designed adaptive inhibitor. Biochemistry 84 12859191
1999 Plasmepsin II, an acidic hemoglobinase from the Plasmodium falciparum food vacuole, is active at neutral pH on the host erythrocyte membrane skeleton. The Journal of biological chemistry 83 10318841
2003 Inhibitors of the Plasmodium falciparum parasite aspartic protease plasmepsin II as potential antimalarial agents. Current medicinal chemistry 79 12678679
2004 Potent inhibitors of the Plasmodium falciparum enzymes plasmepsin I and II devoid of cathepsin D inhibitory activity. Journal of medicinal chemistry 77 14695825
2001 New class of small nonpeptidyl compounds blocks Plasmodium falciparum development in vitro by inhibiting plasmepsins. Antimicrobial agents and chemotherapy 77 11502532
2005 X-ray structure of plasmepsin II complexed with a potent achiral inhibitor. The Journal of biological chemistry 73 15840589
2002 Structures of Ser205 mutant plasmepsin II from Plasmodium falciparum at 1.8 A in complex with the inhibitors rs367 and rs370. Acta crystallographica. Section D, Biological crystallography 73 12454457
2002 Identification and characterization of allophenylnorstatine-based inhibitors of plasmepsin II, an antimalarial target. Biochemistry 71 11841219
1996 Kinetic analysis of plasmepsins I and II aspartic proteases of the Plasmodium falciparum digestive vacuole. Molecular and biochemical parasitology 69 8844673
2007 Evaluation of pH during cytostomal endocytosis and vacuolar catabolism of haemoglobin in Plasmodium falciparum. The Biochemical journal 65 17696875
1999 Crystal structure of the novel aspartic proteinase zymogen proplasmepsin II from plasmodium falciparum. Nature structural biology 62 9886289
1997 Dissection of the pH dependence of inhibitor binding energetics for an aspartic protease: direct measurement of the protonation states of the catalytic aspartic acid residues. Biochemistry 61 9405050
1998 Identification of potent inhibitors of Plasmodium falciparum plasmepsin II from an encoded statine combinatorial library. Bioorganic & medicinal chemistry letters 60 9873534
2003 Design and synthesis of plasmepsin I and plasmepsin II inhibitors with activity in Plasmodium falciparum-infected cultured human erythrocytes. Journal of medicinal chemistry 58 12593654
1999 Active site specificity of plasmepsin II. Protein science : a publication of the Protein Society 56 10548045
2004 Incorporating molecular shape into the alignment-free Grid-Independent Descriptors. Journal of medicinal chemistry 53 15139758
1998 Transgenic mice expressing human fetal globin are protected from malaria by a novel mechanism. Blood 48 9746793
2016 Exploring dual inhibitory role of febrifugine analogues against Plasmodium utilizing structure-based virtual screening and molecular dynamic simulation. Journal of biomolecular structure & dynamics 42 26984239
1997 Plasmodium falciparum, P. vivax, and P. malariae: a comparison of the active site properties of plasmepsins cloned and expressed from three different species of the malaria parasite. Experimental parasitology 42 9371083
2007 Computational inhibitor design against malaria plasmepsins. Cellular and molecular life sciences : CMLS 40 17585371
2003 Creation of a zymogen. Nature structural biology 38 12496934
2018 Overexpression of plasmepsin II and plasmepsin III does not directly cause reduction in Plasmodium falciparum sensitivity to artesunate, chloroquine and piperaquine. International journal for parasitology. Drugs and drug resistance 37 30580023
2011 Structural studies of vacuolar plasmepsins. Biochimica et biophysica acta 37 21540129
2003 C2-symmetric inhibitors of Plasmodium falciparum plasmepsin II: synthesis and theoretical predictions. Bioorganic & medicinal chemistry 37 12901917
1999 Naturally-occurring and recombinant forms of the aspartic proteinases plasmepsins I and II from the human malaria parasite Plasmodium falciparum. FEBS letters 35 10431809
2004 Design of inhibitors against HIV, HTLV-I, and Plasmodium falciparum aspartic proteases. Biological chemistry 34 15576323
2008 Exploring the flap pocket of the antimalarial target plasmepsin II: the "55 % rule" applied to enzymes. ChemMedChem 33 17918177
2004 Plasmepsin II inhibition and antiplasmodial activity of Primaquine-Statine 'double-drugs'. Bioorganic & medicinal chemistry letters 32 15125962
2013 Evaluation of aminohydantoins as a novel class of antimalarial agents. ACS medicinal chemistry letters 31 24900778
2009 New organofluorine building blocks: inhibition of the malarial aspartic proteases plasmepsin II and IV by alicyclic alpha,alpha-difluoroketone hydrates. Organic & biomolecular chemistry 31 19763297
2008 Computer-aided design and synthesis of nonpeptidic plasmepsin II and IV inhibitors. ChemMedChem 29 18752222
2004 Search for substrate-based inhibitors fitting the S2' space of malarial aspartic protease plasmepsin II. Journal of peptide science : an official publication of the European Peptide Society 29 15568678
2006 Replacement of isobutyl by trifluoromethyl in pepstatin A selectively affects inhibition of aspartic proteinases. Chembiochem : a European journal of chemical biology 28 16307463
2011 New benzimidazole derivatives as antiplasmodial agents and plasmepsin inhibitors: synthesis and analysis of structure-activity relationships. Bioorganic & medicinal chemistry letters 27 22204908
2007 The protonation state of the catalytic aspartates in plasmepsin II. FEBS letters 27 17689534
2005 Structure-based drug discovery for Plasmodium falciparum. Combinatorial chemistry & high throughput screening 27 15720193
2022 High-throughput virtual screening approach of natural compounds as target inhibitors of plasmepsin-II. Journal of biomolecular structure & dynamics 26 36469727
2009 Catestatin, an endogenous chromogranin A-derived peptide, inhibits in vitro growth of Plasmodium falciparum. Cellular and molecular life sciences : CMLS 26 20043183
2005 Design and synthesis of potent inhibitors of plasmepsin I and II: X-ray crystal structure of inhibitor in complex with plasmepsin II. Journal of medicinal chemistry 26 15974592
2011 Aryl piperazine and pyrrolidine as antimalarial agents. Synthesis and investigation of structure-activity relationships. Experimental parasitology 25 21354139
2004 Distal substrate interactions enhance plasmepsin activity. The Journal of biological chemistry 25 15574427
2010 Mechanism-based inhibitors of the aspartyl protease plasmepsin II as potential antimalarial agents. Journal of medicinal chemistry 24 20438064
2009 Design and discovery of plasmepsin II inhibitors using an automated workflow on large-scale grids. ChemMedChem 24 19437467
2003 In vitro studies on the mechanism of action of two compounds with antiplasmodial activity: ellagic acid and 3,4,5-trimethoxyphenyl(6'-O-aalloyl)-beta-D-glucopyranoside. Planta medica 24 12624824
2002 Spermine alkaloids from Albizia adinocephala with activity against Plasmodium falciparum plasmepsin II. Phytochemistry 23 12009321
2014 Dietary flavonoids fisetin and myricetin: dual inhibitors of Plasmodium falciparum falcipain-2 and plasmepsin II. Fitoterapia 22 24468190
2012 QSAR, docking and ADMET studies of artemisinin derivatives for antimalarial activity targeting plasmepsin II, a hemoglobin-degrading enzyme from P. falciparum. Current pharmaceutical design 21 22670592
2009 Synthesis, antimalarial evaluation and molecular modeling studies of hydroxyethylpiperazines, potential aspartyl protease inhibitors, part 2. European journal of medicinal chemistry 19 19403210
2009 alpha-Substituted norstatines as the transition-state mimic in inhibitors of multiple digestive vacuole malaria aspartic proteases. Bioorganic & medicinal chemistry 19 19635672
2009 Antimalarial evaluation of copper(II) nanohybrid solids: inhibition of plasmepsin II, a hemoglobin-degrading malarial aspartic protease from Plasmodium falciparum. Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry 19 19946719
2008 Pepsinogen-like activation intermediate of plasmepsin II revealed by molecular dynamics analysis. Proteins 18 18498105
2015 Structures of plasmepsin II from Plasmodium falciparum in complex with two hydroxyethylamine-based inhibitors. Acta crystallographica. Section F, Structural biology communications 17 26625296
2010 Characterisation of hydrazides and hydrazine derivatives as novel aspartic protease inhibitors. Journal of enzyme inhibition and medicinal chemistry 17 20063996
2010 On the orientation of the catalytic dyad in aspartic proteases. Proteins 17 20112416
2006 Plasmepsin II inhibitory activity of alkoxylated and hydroxylated chalcones. The Southeast Asian journal of tropical medicine and public health 17 17121282
2002 De Novo design, synthesis, and in vitro evaluation of a new class of nonpeptidic inhibitors of the malarial enzyme plasmepsin II. Chembiochem : a European journal of chemical biology 17 12404641
2024 A Plasmodium falciparum genetic cross reveals the contributions of pfcrt and plasmepsin II/III to piperaquine drug resistance. mBio 16 38912775
2021 Distribution and Temporal Dynamics of Plasmodium falciparum Chloroquine Resistance Transporter Mutations Associated With Piperaquine Resistance in Northern Cambodia. The Journal of infectious diseases 15 33528566
2020 Modulation of Triple Artemisinin-Based Combination Therapy Pharmacodynamics by Plasmodium falciparum Genotype. ACS pharmacology & translational science 10 33344893
2023 PTEX helps efficiently traffic haemoglobinases to the food vacuole in Plasmodium falciparum. PLoS pathogens 7 37523385
2024 New pyridine-based chalcones and pyrazolines with anticancer, antibacterial, and antiplasmodial activities. Archiv der Pharmazie 5 38548680
2023 Potentials of Terpenoids as Inhibitors of Multiple Plasmodium falciparum Protein Drug Targets. Acta parasitologica 5 37603126
2023 A Plasmodium falciparum genetic cross reveals the contributions of pfcrt and plasmepsin II/III to piperaquine drug resistance. bioRxiv : the preprint server for biology 4 37745488
2023 In silico prediction and in vitro assessment of novel heterocyclics with antimalarial activity. Parasitology research 4 38155300
2025 The plasmepsin-piperaquine paradox persists in Plasmodium falciparum. PLoS pathogens 3 40720544
2024 Inhibition of Plasmodium falciparum plasmepsins by drugs targeting HIV-1 protease: A way forward for antimalarial drug discovery. Current research in structural biology 3 38304146
2023 Antimalarial Activities of a Therapeutic Combination of Azadirachta indica, Mangifera indica and Morinda lucida Leaves: A Molecular View of its Activity on Plasmodium falciparum Proteins. Acta parasitologica 3 37474844
2025 Computational analysis of luteolin, apigenin and their derivatives from Allophylus africanus as potential inhibitors of plasmepsin II a malaria target. BMC chemistry 2 40611287
2025 A review on molecular markers of Plasmodium falciparum. Journal of parasitic diseases : official organ of the Indian Society for Parasitology 2 41230275
2024 Molecular insights into the aspartate protease Plasmepsin II activity inhibition by fluoroquinolones: A pathway to antimalarial drug development. International journal of biological macromolecules 2 39643190
2023 Antimalarial potential, LC-MS secondary metabolite profiling and computational studies of Zingiber officinale. Journal of biomolecular structure & dynamics 2 37116195
2023 Plasmepsin II inhibitory potential of phytochemicals isolated from African antimalarial plants: a computational approach. Journal of biomolecular structure & dynamics 2 37968884
2025 Discovery of a Noncompetitive Open-Flap Selective Inhibitor of Plasmepsin II with Antiplasmodial Activity. Journal of chemical information and modeling 1 39915939
2026 Physico-Chemical Insights into the Catalytic Inhibition of Plasmodium falciparum Plasmepsin II Activity by Repurposing Fluoroquinolone Drugs. The journal of physical chemistry. B 0 41664416
2026 Gene Expression, Docking and Machine Learning in Malaria Drug Discovery: A Systematic Review. Biochemistry research international 0 41768421
2026 A Multidimensional Analysis of the Bimodal Piperaquine Response in Plasmodium falciparum. bioRxiv : the preprint server for biology 0 42465291