Insights in the Antimicrobial Potential of the Natural Nisin Variant Nisin H.

Jens Reiners,Rainer Kalscheuer,Sander H J Smits,Gereon Poschmann,Julia Gottstein,Lutz Schmitt,Marcel Lagedroste,Kai Stühler,Emmanuel T Adeniyi

doi:10.3389/fmicb.2020.573614

Jens Reiners, Rainer Kalscheuer + Show 7 more

Open Access

https://doi.org/10.3389/fmicb.2020.573614

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Abstract

Lantibiotics are a growing class of antimicrobial peptides, which possess antimicrobial activity against mainly Gram-positive bacteria including the highly resistant strains such as methicillin-resistant Staphylococcus aureus or vancomycin-resistant enterococci. In the last decades numerous lantibiotics were discovered in natural habitats or designed with bioengineering tools. In this study, we present an insight in the antimicrobial potential of the natural occurring lantibiotic nisin H from Streptococcus hyointestinalis as well as the variant nisin H F1I. We determined the yield of the heterologously expressed peptide and quantified the cleavage efficiency employing the nisin protease NisP. Furthermore, we analyzed the effect on the modification via mass spectrometry analysis. With standardized growth inhibition assays we benchmarked the activity of pure nisin H and the variant nisin H F1I, and their influence on the activity of the nisin immunity proteins NisI and NisFEG from Lactococcus lactis and the nisin resistance proteins SaNSR and SaNsrFP from Streptococcus agalactiae COH1. We further checked the antibacterial activity against clinical isolates of Staphylococcus aureus, Enterococcus faecium and Enterococcus faecalis via microdilution method. In summary, nisin H and the nisin H F1I variant possessed better antimicrobial potency than the natural nisin A.

Highlights

IntroductionLantibiotics (lanthionine containing antibiotics) are a growing class of antimicrobial peptides (AMPs), which posses antimicrobial activity even against highly resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) and some are already in pre-clinical trials (Mota-Meira et al, 2000; Jabes et al, 2011; Dawson and Scott, 2012; Crowther et al, 2013; Dischinger et al, 2014; Ongey et al, 2017; Brunati et al, 2018; Sandiford, 2019)
We focused in this study on the natural variant nisin H and the nisin H F1I mutant
We showed the heterologous expression of nisin H and the F1I variant with the NICE-system in L. lactis (Eichenbaum et al, 1998; Mierau and Kleerebezem, 2005; Rink et al, 2005; Zhou et al, 2006; Lagedroste et al, 2019) and extended the characterization in terms of cleavage efficiency by the protease NisP and the antimicrobial activity against the immunity proteins NisFEG (Alkhatib et al, 2014b) and NisI (Alkhatib et al, 2014a), as well as the resistance proteins SaNSR (Khosa et al, 2013; Khosa et al, 2016a,b) and SaNsrFP (Khosa et al, 2016a; Reiners et al, 2017)

Summary

Introduction

Lantibiotics (lanthionine containing antibiotics) are a growing class of antimicrobial peptides (AMPs), which posses antimicrobial activity even against highly resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) and some are already in pre-clinical trials (Mota-Meira et al, 2000; Jabes et al, 2011; Dawson and Scott, 2012; Crowther et al, 2013; Dischinger et al, 2014; Ongey et al, 2017; Brunati et al, 2018; Sandiford, 2019). The step is a Michael-type condensation of dehydrated residues with the thiol group of a cysteine residue, thereby forming (methyl)-lanthionine rings, guided in a regio- and stereospecific manner by the cyclase NisC (class I lantibiotic cyclase) (Okeley et al, 2003; Li et al, 2006; Li and van der Donk, 2007; Repka et al, 2017). These characteristic (methyl)-lanthionine rings give lantibiotics high heat stability, resistance against proteolytic digestion and are responsible for the nanomolar antimicrobial activity (Gross and Morell, 1967; Rollema et al, 1995; Chan et al, 1996; Lu et al, 2010; Oppedijk et al, 2016)

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