Dipeptidyl peptidase 3, a novel protease from Leishmania braziliensis

Abstract

The increase of leishmaniasis cases worldwide and the emergence of Leishmania strains resistant to current treatments make necessary to find new therapeutic targets. Proteases are appealing drug targets because they play pivotal roles in facilitating parasite survival and promoting pathogenesis. Enzymes belonging to the dipeptidyl peptidase 3 (DPP3) group have been described in different organisms such as mammals, insects and yeast, in which these enzymes have been involved in both protein turnover and protection against oxidative damage. The aim of this work was to characterize the structure and function of the Leishmania braziliensis DPP3 (LbDPP3) protein as the first step to elucidate its suitability as a potential drug target. Sequence alignment showed 43% of identity between LbDPP3 and its human orthologous (hDPP3) enzyme. Although the modeled protein adopted a globally conserved three-dimensional (3D) structure, structural differences were found in the vicinity of the active site and the substrate binding-cleft. In addition, the Leishmania protein was expressed as a soluble recombinant protein and its kinetics parameters were determined using the z-Arginine-Arginine-AMC substrate. The LbDPP3 activity was maximal at pH values between 8.0–8.5. Interestingly, classical enzyme inhibitors such as the tynorphin and its derivative peptide IVYPW were found to actively inhibit the LbDPP3 activity. Moreover, these DPP3 inhibitors showed a detrimental effect upon parasite survival, decreasing the viability of promastigotes by up to 29%. Finally, it was observed that LbDPP3 was equally expressed along the in vitro differentiation from promastigotes to axenic amastigotes. In conclusion, these findings suggest that the L. brazileinsis DPP3 could be a promising drug target.

Quantitative Proteomics Reveals that Hsp90 Inhibition Dynamically Regulates Global Protein Synthesis in Leishmania mexicana

“…The statistically significant proteins (red filled circles at upper right portion of Fig. 3D ) preferentially synthesized by the parasite under severe Hsp90 inhibition include known virulence factors superoxide dismutase (SOD) ( 44 ), Hsp70 ( 45 ), and dipeptidyl peptidase 3 ( 46 ), important metabolic enzymes, and histone H4. Gene ontology (GO) analysis of the statistically significant upregulated proteins revealed unfolded protein binding ( P value, 3.77e −6 ) and protein folding ( P value, 2.53e −7 ) as significantly enriched molecular function and biological process GO terms, respectively ( Fig.…”

Serine Proteinases in Leishmania (Viannia) braziliensis Promastigotes Have Distinct Subcellular Distributions and Expression

“…Differences were also observed in the prediction of the subcellular localizations of these proteins, which was based only on sequence properties by using a deep neural network provided by the DeepLoc-1 server. The accuracy of these analyses was assessed with three L. (V.) braziliensis proteins (two with RNA binding capacity (LbrM.25.2210 and LbrM.30.3080) [15], and dipeptidyl-peptidase 3 (LbrM.05.0940) [16], all of which have experimentally defined subcellular locations. The program accurately identified the cellular location of LbrM.25.2210 as the parasite nucleus (0.50) and LbrM.30.3080 and LbrM.05.0940 as the cytoplasm (0.85 and 0.97, respectively, data not shown).…”

Dipeptidyl peptidase III as a DNA marker to investigate epidemiology and taxonomy of Old World Leishmania species

“…Studies suggested the involvement of the human DPPIII protein in protein turn over, oxidative stress and pain modulation and inflammation [49]. In Leishmania, the protein was characterized in L. braziliensis demonstrating its role in parasite survival in the vector, or host environments through peptide degradation and thus use of amino acids for energy production in stressful environment [50]. Presence of this protein was demonstrated in the secretome of L. donovani, which classified it as a candidate virulence factor that might be part of a stress response of the parasite [51].…”

“…Presence of this protein was demonstrated in the secretome of L. donovani, which classified it as a candidate virulence factor that might be part of a stress response of the parasite [51]. A 2040bp DPPIII gene is present in all Leishmania and other trypanosomatids sequenced genomes [50]. However, the gene seemed absent in the Trypanosoma genus including T. brucei and T. cruzi species [50,52].…”

“…A 2040bp DPPIII gene is present in all Leishmania and other trypanosomatids sequenced genomes [50]. However, the gene seemed absent in the Trypanosoma genus including T. brucei and T. cruzi species [50,52]. The L. braziliensis DPPIII translated sequence has a 65-80% similarity rate to other microorganisms belonging to Endotrypanum, Blechomonas, Crithidia and Leptomonas genera [50].…”