Enzymatic Characterization of Recombinant Food Vacuole Plasmepsin 4 from the Rodent Malaria Parasite Plasmodium berghei

Liu, Peng; Robbins, A.H.; Marzahn, Melissa R.; McClung, Scott; Yowell, Charles A.; Stevens, Stanley M.; Dame, John B.; Dunn, Ben M.

doi:10.1371/journal.pone.0141758

Cited by 4 publications

(3 citation statements)

References 91 publications

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“…Recombinant PM4s from the other three human malaria parasites and the rodent malarial parasite P. berghei were similarly produced and activated [54,126,133]. The subsite specificity at S3 -S3' of the five PM4 orthologs (i.e., PfPM4, PoPM4, PvPM4, PmPM4 and PbPM4) was investigated using combinatorial peptide libraries [125,133]. All five PM4s unanimously prefer accommodating phenylalanine or tyrosine at S1 and S1', except that PbPM4 accommodates norleucine best at S1'.…”

Section: Plasmepsin 4 Orthologsmentioning

confidence: 99%

Plasmepsin: Function, Characterization and Targeted Antimalarial Drug Development

Liu¹

2017

Natural Remedies in the Fight Against Parasites

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The devastating malaria, caused by parasites of the genus Plasmodium, afflicts nearly half of the world's population and imposes a heavy socioeconomic burden particularly to the disease-endemic Sub-Saharan Africa. Sustained efforts in malaria control have been made from the perspectives of medicine-and vaccine-based prevention and treatment of malaria and malaria transmission blockage for the past 15 years, resulting in a decreased mortality rate by 60% and a decreased malaria incidence rate by 37% globally. Nonetheless, due to the emergence and rapid spread of drug-resistant parasite strains, novel antimalarial drugs are urgently required to combat this deadly disease. Plasmepsins are deemed potential targets for novel antimalarial drug design. Plasmepsins represent an aspartic proteinase family that can be subcategorized into seven groups based on the amino acid sequence identity. This chapter discusses our progress in understanding the biosynthesis, biological functions and enzymatic characteristics of the plasmepsin family. This led to development of various types of plasmepsin-targeted compounds and the assessment of their binding affinity and selectivity, anti-parasitic activity and cytotoxicity. The gained experience and current status in developing plasmepsin-targeted antimalarial drugs are addressed. Finally, a deeper and broader investigation on the functions and characteristics of the plasmepsin family is encouraged.

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Section: Plasmepsin 4 Orthologsmentioning

confidence: 99%

Plasmepsin: Function, Characterization and Targeted Antimalarial Drug Development

Liu¹

2017

Natural Remedies in the Fight Against Parasites

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“…It has also been shown that the prosegment does not suppress the activity of the mature part, which then can cleave a substrate peptide [37]. It was observed that pro-tPM from P. berghei could bind a substrate in the active site cleft even in the presence of the prosegment [38]. The pro-tPMV zymogen is catalytically active [39,40] and no release of prosegment is observed under acidic conditions, both during auto-activation and in vivo [39,41].…”

Section: Discussionmentioning

confidence: 99%

Activation mechanism of plasmepsins, pepsin‐like aspartic proteases from Plasmodium, follows a unique trans‐activation pathway

et al. 2020

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Plasmodium parasites that cause malaria produce plasmepsins (PMs), pepsin‐like aspartic proteases that are important antimalarial drug targets due to their role in host hemoglobin degradation. The enzymes are synthesized as inactive zymogens (pro‐PMs), and the mechanism of their conversion to the active, mature forms has not been clearly elucidated. Our structural investigations of vacuolar pro‐PMs with truncated prosegment (pro‐tPMs) reveal that the formation of the S‐shaped dimer is their innate property. Further structural studies, biochemical analysis, and molecular dynamics simulations indicate that disruption of the Tyr‐Asp loop (121p‐4), coordinated with the movement of the loop L1 (237–247) and helix H2 (101p–113p), is responsible for the extension of the pro‐mature region (harboring the cleavage site). Consequently, under acidic pH conditions, these structural changes result in the dissociation of the dimers to monomers and the protonation of the residues in the prosegment prompts its unfolding. Subsequently, we demonstrated that the active site of the monomeric pro‐tPMs with the unfolded prosegment is accessible for peptide substrate binding; in contrast, the active site is blocked in folded prosegment form of pro‐tPMs. Thus, we propose a novel mechanism of auto‐activation of vacuolar pro‐tPMs that under acidic conditions can form a catalytically competent active site. One monomer cleaves the prosegment of the other one through a trans‐activation process, resulting in formation of mature enzyme. As a result, once a mature enzyme is generated, it leads to the complete conversion of all the inactive pro‐tPMs to their mature form.DatabaseAtomic coordinates and structure factors have been submitted in the Protein Data Bank (PDB) under the PDB IDs 6KUB, 6KUC, and 6KUD.

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“…malariae as well as in the rodent malaria parasite P . berghei , Plasmepsin 4 (PM4) is the only aspartic protease localised within the digestive vacuole [ 22 , 23 ]. The PM5, PM9 and PM10 are the other aspartyl proteases expressed within asexual blood stage of the malaria parasite but not localised within the digestive vacuole [ 24 ].…”

Section: Introductionmentioning

confidence: 99%

Deciphering the targets of retroviral protease inhibitors in Plasmodium berghei

Onchieku

Mogire

Ndung'u³

et al. 2018

PLoS ONE

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Retroviral protease inhibitors (RPIs) such as lopinavir (LP) and saquinavir (SQ) are active against Plasmodium parasites. However, the exact molecular target(s) for these RPIs in the Plasmodium parasites remains poorly understood. We hypothesised that LP and SQ suppress parasite growth through inhibition of aspartyl proteases. Using reverse genetics approach, we embarked on separately generating knockout (KO) parasite lines lacking Plasmepsin 4 (PM4), PM7, PM8, or DNA damage-inducible protein 1 (Ddi1) in the rodent malaria parasite Plasmodium berghei ANKA. We then tested the suppressive profiles of the LP/Ritonavir (LP/RT) and SQ/RT as well as antimalarials; Amodiaquine (AQ) and Piperaquine (PQ) against the KO parasites in the standard 4-day suppressive test. The Ddi1 gene proved refractory to deletion suggesting that the gene is essential for the growth of the asexual blood stage parasites. Our results revealed that deletion of PM4 significantly reduces normal parasite growth rate phenotype (P = 0.003). Unlike PM4_KO parasites which were less susceptible to LP and SQ (P = 0.036, P = 0.030), the suppressive profiles for PM7_KO and PM8_KO parasites were comparable to those for the WT parasites. This finding suggests a potential role of PM4 in the LP and SQ action. On further analysis, modelling and molecular docking studies revealed that both LP and SQ displayed high binding affinities (-6.3 kcal/mol to -10.3 kcal/mol) towards the Plasmodium aspartyl proteases. We concluded that PM4 plays a vital role in assuring asexual stage parasite fitness and might be mediating LP and SQ action. The essential nature of the Ddi1 gene warrants further studies to evaluate its role in the parasite asexual blood stage growth as well as a possible target for the RPIs.

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Enzymatic Characterization of Recombinant Food Vacuole Plasmepsin 4 from the Rodent Malaria Parasite Plasmodium berghei

Cited by 4 publications

References 91 publications

Plasmepsin: Function, Characterization and Targeted Antimalarial Drug Development

Plasmepsin: Function, Characterization and Targeted Antimalarial Drug Development

Activation mechanism of plasmepsins, pepsin‐like aspartic proteases from Plasmodium, follows a unique trans‐activation pathway

Deciphering the targets of retroviral protease inhibitors in Plasmodium berghei

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