Phosphate Ions Alter the Binding of Daptomycin to Living Bacterial Cell Surfaces.
Lindsey N MillerMarea J BlakeEleanor F PageHannah B CastilloTessa R CalhounPublished in: ACS infectious diseases (2021)
Advancements in antibiotic drug design are often hindered by missing information on how these small molecules interact with living cells. The antibiotic, daptomycin, has found clinical success and an emerging resistance, but a comprehensive picture of its mechanism of action has remained elusive. Using a surface-specific spectroscopy technique, second harmonic generation, we are able to quantitatively assess the binding of daptomycin to living cell membranes without the addition of exogenous labels. Our results reveal similar binding affinities for both Gram-positive and Gram-negative bacteria studied, including Escherichia coli. More importantly, we show that the presence of phosphate ions influences the binding of daptomycin to the Gram-positive bacterium Enterococcus faecalis. The role of environmental phosphate has not previously been considered in any proposed mechanism, and its implications are expected to be important in vivo.
Keyphrases
- living cells
- methicillin resistant staphylococcus aureus
- single cell
- escherichia coli
- single molecule
- fluorescent probe
- binding protein
- dna binding
- gram negative
- quantum dots
- gene expression
- staphylococcus aureus
- stem cells
- healthcare
- biofilm formation
- genome wide
- pseudomonas aeruginosa
- health information
- risk assessment
- social media
- mass spectrometry
- water soluble
- solid state