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oai:docta.ucm.es:20.500.14352/1033222025-03-18T12:32:22Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Cabrera-Muñoz, Aymara author Sierra-Gómez, Yusvel author Covaleda-Cortés, Giovanni author Reytor, Mey L. author González-González, Yamile author Bautista Santa Cruz, José Manuel author Avilés, Francesc Xavier author Alonso-del-Rivero, Maday author 2023-01-28 Metallocarboxypeptidases are zinc-dependent peptide-hydrolysing enzymes involved in several important physiological and pathological processes. They have been a target of growing interest in the search for natural or synthetic compound binders with biomedical and drug discovery purposes, i.e., with potential as antimicrobials or antiparasitics. Given that marine resources are an extraordinary source of bioactive molecules, we screened marine invertebrates for new inhibitory compounds with such capabilities. In this work, we report the isolation and molecular and functional characterization of NpCI, a novel strong metallocarboxypeptidase inhibitor from the marine snail Nerita peloronta. NpCI was purified until homogeneity using a combination of affinity chromatography and RP-HPLC. It appeared as a 5921.557 Da protein with 53 residues and six disulphide-linked cysteines, displaying a high sequence similarity with NvCI, a carboxypeptidase inhibitor isolated from Nerita versicolor, a mollusc of the same genus. The purified inhibitor was determined to be a slow- and tight-binding inhibitor of bovine CPA (Ki = 1.1·× 10−8 mol/L) and porcine CPB (Ki = 8.15·× 10−8 mol/L) and was not able to inhibit proteases from other mechanistic classes. Importantly, this inhibitor showed antiplasmodial activity against Plasmodium falciparum in an in vitro culture (IC50 = 5.5 μmol/L), reducing parasitaemia mainly by inhibiting the later stages of the parasite’s intraerythrocytic cycle whilst having no cytotoxic effects on human fibroblasts. Interestingly, initial attempts with other related proteinaceous carboxypeptidase inhibitors also displayed similar antiplasmodial effects. Coincidentally, in recent years, a metallocarboxypeptidase named PfNna1, which is expressed in the schizont phase during the late intraerythrocytic stage of the parasite’s life cycle, has been described. Given that NpCI showed a specific parasiticidal effect on P. falciparum, eliciting pyknotic/dead parasites, our results suggest that this and related inhibitors could be promising starting agents or lead compounds for antimalarial drug discovery strategies. Cabrera-Muñoz, Aymara, Yusvel Sierra-Gómez, Giovanni Covaleda-Cortés, Mey L. Reytor, Yamile González-González, José M. Bautista, Francesc Xavier Avilés, and Maday Alonso-del-Rivero. 2023. "Isolation and Characterization of NpCI, a New Metallocarboxypeptidase Inhibitor from the Marine Snail Nerita peloronta with Anti-Plasmodium falciparum Activity" Marine Drugs 21, no. 2: 94. https://doi.org/10.3390/md21020094 1660-3397 10.3390/md21020094 https://hdl.handle.net/20.500.14352/103322 https://doi.org/10.3390/md21020094 36827135 Isolation and Characterization of NpCI, a New Metallocarboxypeptidase Inhibitor from the Marine Snail Nerita peloronta with Anti-Plasmodium falciparum Activity