Design of Protegrin-1 Analogs with Improved Antibacterial Selectivity

• Main Authors: Ilia A. Bolosov (Author), Pavel V. Panteleev (Author), Sergei V. Sychev (Author), Veronika A. Khokhlova (Author), Victoria N. Safronova (Author), Ilia Yu. Toropygin (Author), Tatiana I. Kombarova (Author), Olga V. Korobova (Author), Eugenia S. Pereskokova (Author), Alexander I. Borzilov (Author), Tatiana V. Ovchinnikova (Author), Sergey V. Balandin (Author)
• Format: Book
• Published: MDPI AG, 2023-07-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Protegrin-1 (PG-1) is a cationic β-hairpin pore-forming antimicrobial peptide having a membranolytic mechanism of action. It possesses in vitro a potent antimicrobial activity against a panel of clinically relevant MDR ESKAPE pathogens. However, its extremely high hemolytic activity and cytotoxicity toward mammalian cells prevent the further development of the protegrin-based antibiotic for systemic administration. In this study, we rationally modulated the PG-1 charge and hydrophobicity by substituting selected residues in the central β-sheet region of PG-1 to design its analogs, which retain a high antimicrobial activity but have a reduced toxicity toward mammalian cells. In this work, eight PG-1 analogs with single amino acid substitutions and five analogs with double substitutions were obtained. These analogs were produced as thioredoxin fusions in <i>Escherichia coli</i>. It was shown that a significant reduction in hemolytic activity without any loss of antimicrobial activity could be achieved by a single amino acid substitution, V16R in the <i>C</i>-terminal β-strand, which is responsible for the PG-1 oligomerization. As the result, a selective analog with a ≥30-fold improved therapeutic index was obtained. FTIR spectroscopy analysis of analog, [V16R], revealed that the peptide is unable to form oligomeric structures in a membrane-mimicking environment, in contrast to wild-type PG-1. Analog [V16R] showed a reasonable efficacy in septicemia infection mice model as a systemic antibiotic and could be considered as a promising lead for further drug design.

Item Description

10.3390/pharmaceutics15082047
1999-4923