Recombinant plasmepsin 1 from the human malaria parasite plasmodium falciparum: enzymatic characterization, active site inhibitor design, and structural analysis.
A mutated form of truncated proplasmepsin 1 (proPfPM1) from the human malaria parasite Plasmodium falciparum, proPfPM1 K110pN, was generated and overexpressed in Escherichia coli. The automaturation process was carried out at pH 4.0 and 4.5, and the optimal catalytic pH of the resulting mature PfPM1 was determined to be pH 5.5. This mature PfPM1 showed comparable binding affinity to peptide substrates and inhibitors with the naturally occurring form isolated from parasites. The S3-S3' subsite preferences of the recombinant mature PfPM1 were explored using combinatorial chemistry based peptide libraries. On the basis of the results, a peptidomimetic inhibitor (compound 1) was designed and yielded 5-fold selectivity for binding to PfPM1 versus the homologous human cathepsin D (hcatD). The 2.8 A structure of the PfPM2-compound 1 complex is reported. Modeling studies were conducted using a series of peptidomimetic inhibitors (compounds 1-6, Table 3) and three plasmepsins: the crystal structure of PfPM2, and homology derived models of PfPM1 and PfPM4.
Liu
Peng
P
Department of Biochemistry and Molecular Biology, University of Florida, College of Medicine, Gainesville, Florida 32610-0245, USA.
Marzahn
Melissa R
MR
Robbins
Arthur H
AH
Gutiérrez-de-Terán
Hugo
H
Rodríguez
David
D
McClung
Scott H
SH
Stevens
Stanley M
SM
Yowell
Charles A
CA
Dame
John B
JB
McKenna
Robert
R
Dunn
Ben M
BM
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites / Q000235:genetics; D002384:Catalysis; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D016778:Malaria, Falciparum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010963:Plasmodium falciparum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D020673:Protein Renaturation; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012995:Solubility; D013329:Structure-Activity Relationship; D013379:Substrate Specificity / Q000235:genetics
D004791:Enzyme Inhibitors; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D016282:Aspartic Acid Endopeptidases; C089643:plasmepsin