Daptomycin, a last-resort antibiotic, binds ribosomal protein S19 in humans

Michael Gotsbacher, Sungmin Cho, Ho Jeong Kwon*, Peter Karuso

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)
19 Downloads (Pure)


Daptomycin is a recently introduced, last-resort antibiotic that displays a unique mode of action against Gram-positive bacteria that is not fully understood. Several bacterial targets have been proposed but no human binding partner is known.

In the present study we tested daptomycin in cell viability and proliferation assays against six human cell lines, describe the synthesis of biotinylated and fluorescently labeled analogues of daptomycin. Biotinylated daptomycin was used as bait to isolate the human binding partner by the application of reverse chemical proteomics using T7 phage display of five human tumor cDNA libraries. The interaction between the rescued protein and daptomycin was validated via siRNA knockdown, DARTS assay and immunocytochemistry.

We have found that daptomycin possesses selective growth inhibition of some cancer cell lines, especially MCF7. The unbiased interrogation of human cDNA libraries, displayed on bacteriophage T7, revealed a single human target of daptomycin; ribosomal protein S19. Using a drug affinity responsive target stability (DARTS) assay in vitro, we show that daptomycin stabilizes RPS19 toward pronase. Fluorescently labeled daptomycin stained specific structures in HeLa cells and co-localized with a RPS19 antibody.

This study provides, for the first time, a human protein target of daptomycin and identifies RPS19 as a possible anticancer drug target for the development of new pharmacological applications and research.
Original languageEnglish
Article number16
Pages (from-to)1-15
Number of pages15
JournalProteome Science
Issue number1
Publication statusPublished - 1 Jul 2017

Bibliographical note

Copyright the Author(s) 2017. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


  • daptomycin
  • reverse chemical proteomics
  • phage display


Dive into the research topics of 'Daptomycin, a last-resort antibiotic, binds ribosomal protein S19 in humans'. Together they form a unique fingerprint.

Cite this