A new Kunitz trypsin inhibitor from Erythrina poeppigiana exhibits antimicrobial and antibiofilm properties against bacteria.

Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 2021 Dec

filter terms:

Erythrina poeppigiana belongs to Fabaceae family (subfamily Papillionoideae) and is commonly found in tropical and subtropical regions in Brazil. Herein, we described the purification and characterization of a new Kunitz-type inhibitor, obtained from E. poeppigiana seeds (EpTI). EpTI is composed by three isoforms of identical amino-terminal sequences with a molecular weight ranging from 17 to 20 kDa. The physicochemical features showed by EpTI are common to Kunitz inhibitors, including the dissociation constant (13.1 nM), stability against thermal (37-100 °C) and pH (2-10) ranging, and the presence of disulfide bonds stabilizing its reactive site. Furthermore, we investigated the antimicrobial, anti-adhesion, and anti-biofilm properties of EpTI against Gram-positive and negative bacteria. The inhibitor showed antimicrobial activity with a minimum inhibitory concentration (MIC, 5-10 µM) and minimum bactericidal concentration (MBC) of 10 µM for Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus haemolyticus. The combination of EpTI with ciprofloxacin showed a marked synergistic effect, reducing the antibiotic concentration by 150%. The increase in crystal violet uptake for S. aureus and K. pneumoniae strains was approximately 30% and 50%, respectively, suggesting that the bacteria plasma membrane is targeted by EpTI. Treatment with EpTI at 1x and 10 x MIC significantly reduced the biofilm formation and prompted the disruption of a mature biofilm. At MIC/2, EpTI decreased the bacterial adhesion to polystyrene surface within 2 h. Finally, EpTI showed low toxicity in animal model Galleria mellonella. Given its antimicrobial and anti-biofilm properties, the EpTI sequence might be used to design novel drug prototypes. Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

Citation

Karina Margareti Alencar de Barros, Janaina de Cássia Orlandi Sardi, Simone Maria-Neto, Alexandre José Macedo, Suellen Rodrigues Ramalho, Daniella Gorete Lourenço de Oliveira, Gemilson Soares Pontes, Simone Schneider Weber, Caio Fernando Ramalho de Oliveira, Maria Lígia Rodrigues Macedo. A new Kunitz trypsin inhibitor from Erythrina poeppigiana exhibits antimicrobial and antibiofilm properties against bacteria. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2021 Dec;144:112198