%0 Journal Article
%T Redirecting Pore Assembly of Staphylococcal ¦Á-Hemolysin by Protein Engineering
%J -
%D 2019
%R https://doi.org/10.1021/acscentsci.8b00910
%X High Resolution Image Download MS PowerPoint Slide ¦Á-Hemolysin (¦ÁHL), a ¦Â-barrel pore-forming toxin (¦ÂPFT), is secreted as a water-soluble monomer by Staphylococcus aureus. Upon binding to receptors on target cell membranes, ¦ÁHL assembles to form heptameric membrane-spanning pores. We have previously engineered ¦ÁHL to create a protease-activatable toxin that is activated by site-specific proteolysis including by tumor proteases. In this study, we redesigned ¦ÁHL so that it requires 2-fold activation on target cells through (i) binding to specific receptors, and (ii) extracellular proteolytic cleavage. To assess our strategy, we constructed a fusion protein of ¦ÁHL with galectin-1 (¦ÁHLG1, ¦ÁHL-Galectin-1 chimera). ¦ÁHLG1 was cytolytic toward cells that lack a receptor for wild-type ¦ÁHL. We then constructed protease-activatable mutants of ¦ÁHLG1 (PAM¦ÁHLG1s). PAM¦ÁHLG1s were activated by matrix metalloproteinase 2 (MMP-2) and had approximately 50-fold higher cytolytic activity toward MMP-2 overexpressing cells (HT-1080 cells) than toward non-overexpressing cells (HL-60 cells). Our approach provides a novel strategy for tailoring pore-forming toxins for therapeutic applications
%U https://pubs.acs.org/doi/10.1021/acscentsci.8b00910