Differences in biochemical properties of the Plasmodial falcipain-2 and berghepain-2 orthologues: implications for in vivo screens of inhibitors.
Falcipain-2A, the cysteine protease of Plasmodium falciparum has been proposed as a good drug target. This study evaluated the suitability of Plasmodium berghei as the animal model and reports the first functional expression and characterization of the falcipain-2A orthologue, berghepain-2. Comparative studies revealed that the orthologues exhibited different biochemical properties. Berghepain-2 demonstrated optimal activity at a narrower pH optima of 5.5-6 and a lack of preference for substrates with leucine at position 2. Mutagenesis studies revealed roles for residues Val63 and Arg230 of berghepain-2 in contributing to its distinctive biochemical properties. This warrants re-evaluation of employing P. berghei as the murine model for the in vivo screening of falcipain-2A inhibitors. More importantly, these findings stress the underlying importance of establishing the functionality of relevant genes of P. falciparum with concomitant relevance to its murine counterpart prior to its use as the animal model for the screening of potential antimalarials.
Chan
Cheryl
C
Department of Microbiology, National University of Singapore, 5 Science Drive 2, MD4A, Singapore 117597, Singapore.
Goh
Liuh Ling
LL
Sim
Tiow-Suan
TS
D000595:Amino Acid Sequence; D000818:Animals; D000962:Antimalarials; D001483:Base Sequence; D017124:Conserved Sequence; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D017931:DNA Primers; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010962:Plasmodium berghei / Q000201:enzymology*; D010963:Plasmodium falciparum / Q000201:enzymology*; D015800:Protozoan Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D000962:Antimalarials; D015853:Cysteine Proteinase Inhibitors; D017931:DNA Primers; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D003546:Cysteine Endopeptidases; C416224:falcipain 2