Effect of Amino Acid Substitutions on 70S Ribosomal Binding, Cellular Uptake, and Antimicrobial Activity of Oncocin Onc112. (12th January 2022)

• Record Type: Journal Article
• Authors: Kolano, Lisa; Knappe, Daniel; Berg, Angela; Berg, Thorsten; Hoffmann, Ralf
• Is Part Of: Chembiochem. Volume 23:Number 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-12
• Subjects: fluorescence polarization (FP) -- label-free quantitation -- Onc112 -- oncocin -- proline-rich antimicrobial peptide (PrAMP); Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pharmaceutical chemistry -- Periodicals; 572
• DOI: 10.1002/cbic.202100609
• Languages: English
• ISSNs: 1439-4227

Abstract

Abstract: Proline‐rich antimicrobial peptides (PrAMPs) are promising candidates for the treatment of infections caused by high‐priority human pathogens. Their mode of action consists of (I) passive diffusion across the outer membrane, (II) active transport through the inner membrane, and (III) inhibition of protein biosynthesis by blocking the exit tunnel of the 70S ribosome. We tested whether in vitro data on ribosomal binding and bacterial uptake could predict the antibacterial activity of PrAMPs against Gram‐negative and Gram‐positive bacteria. Ribosomal binding and bacterial uptake rates were measured for 47 derivatives of PrAMP Onc112 and compared to the minimal inhibitory concentrations (MIC) of each peptide. Ribosomal binding was evaluated for ribosome extracts from four Gram‐negative bacteria. Bacterial uptake was assessed by quantifying each peptide in the supernatants of bacterial cultures. Oncocin analogues with a higher net positive charge appeared to be more active, although their ribosome binding and uptake rates were not necessarily better than for Onc112. The data suggest a complex mode of action influenced by further factors improving or reducing the antibacterial activity, including diffusion through membranes, transport mechanism, secondary targets, off‐target binding, intracellular distribution, and membrane effects. Relying only on in vitro binding and uptake data may not be sufficient for the rational development of more active analogues. Abstract : The antibacterial activity of substituted oncocin Onc112 peptides varied widely among different bacterial species, which could be partially explained by ribosome binding and cellular uptake. Onc112 analogues with a higher net positive charge appeared to be more active, although their ribosome binding and uptake rates were not necessarily better suggesting a complex mode of action.