Lucas Carvalho de Freitas1, Poliana Gomes da Silva2, Roberto Afonso da Silva3, Lindomar José Pena2, Tercilio Calsa Junior1
The health and socioeconomic challenges caused by arboviruses of epidemiological importance, such as Chincungunya (CHIKV), highlight the need to develop more effective prophylactic and therapeutic strategies. The prospection of bioactive molecules with antiviral properties emerges as an alternative for the development of new therapeutic approaches against arboviruses and their associated diseases. Opuntia stricta (Haw.) is cultivated plant in the Brazilian semi-arid region with relevant socioeconomic importance for the native population, and a source of proteins and peptides with potential antiviral biotechnological applicability. Thus, the present study aimed to evaluate the anti-ZIKV activity of proteins obtained from the aqueous extract of O. stricta and to identify the potential proteins associated with antiviral activity. The proteins present in the aqueous extract of the cladodes of O. stricta clone IPA200016 were obtained through ammonium sulfate precipitation at saturation of 0 – 30 and 30 – 60 % (m:v). The protein fractions obtained were tested for cytotoxicity by the MTT test and anti-ZIKV activity evaluated by TCID50/mL. The proteins present in the protein fractions were submitted to enzymatic digestion with trypsin and analyzed by UPLC-MS/MS, using the Q-ToF Synapt XS system (Waters). The obtained spectra were processed for protein identification by the Progensesis.QI v 4.7 (Nonlinear Dynamics) software. The cytotoxicity and antiviral data demonstrate that the precipitated protein fraction in the saturation range of 30–60% showed lower cytotoxicity and higher antiviral activity against ZIKV, compared to the fraction corresponding to the saturation of 0–30%. Within the identified proteins in this fraction, a notable group comprises rRNA N-glycosylases possessing catalytic domains analogous to those of type I ribosome-inactivating proteins (RIPs). Type I RIPs are widely recognized for their low cytotoxicity and antiviral activity in vitro, previously observed against viruses such as DENV, HIV, H1N1. Thus, the type I RIPs of O. stricta identified in the respective study can be directed to the development of new therapeutic strategies against arboviruses.
Agradecimentos: CAPES, Universidade Federal de Pernambuco, Laboratório de Genômica e Proteômica de Plantas, Programa de Pós-Graduação em Genética e Biologia Molecular, Instituto Aggeu Magalhães/Fiocruz-PE, Instituto Keizo Asami