The biotinylated probes based on anticancer saponin OSW-1 with varied linker lengths were synthesized and their cell growth inhibitory activity and affinity pulldown efficiency were evaluated. All probes demonstrated comparable cytotoxicity to the parent natural product, highlighting that the linker moiety had a minimal impact on cell uptake or target engagement. In contrast, when evaluated against the known target proteins, OSBP and ORP4, the biotinylated probe 3 with PEG5 linker enabled most effective enrichment of target proteins in the affinity pulldown assay, suggesting that the cytotoxicity and pulldown efficiency did not correlate among the probes studied. Our data provided the first evidence that OSW-1 specifically binds to endogenously expressed OSBP and ORP4. The selectivity of affinity pulldown using probe 3 was also validated by facile identification of the enriched protein by silver staining and LC/MS analysis. Therefore, probe 3 with PEG5 linker comprising of 25 atoms (28 Å) was found as an optimal biotinylated probe for isolating OSW-1 binding proteins from cell lysate.
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http://dx.doi.org/10.1002/cbic.202400923 | DOI Listing |
J Exp Med
February 2025
School of Basic Medical Sciences, Center for Infection Biology, Tsinghua University, Beijing, China.
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The Ebola virus, a filovirus, has been responsible for significant human fatalities since its discovery. Despite extensive research, effective small-molecule drugs remain elusive due to its complex pathogenesis. Inhibition of RNA synthesis is a promising therapeutic target, and the VP30 protein plays a critical role in this process.
View Article and Find Full Text PDFFEBS J
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Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Hungary.
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