• Orbit mini

    Simultaneous recording from four lipid bilayers

2017 - Engineering a pH responsive pore forming protein

Icon Orbit Mini  Orbit mini and   icon vpp   Vesicle Prep Pro publication in Scientific Reports (2017)

Authors: 
Kisovec M., Rezelj S., Knap P., Cajnko M.M., Caserman S., Flašker A., Žnidaršič N., Repič M., Mavri J., Ruan Y., Scheuring S., Podobnik M., Anderluh G.

Journal: 
Nature Scientific Reports (2017) 7:42231


Abstract: 

Listeriolysin O (LLO) is a cytolysin capable of forming pores in cholesterol-rich lipid membranes of host cells. It is conveniently suited for engineering a pH-governed responsiveness, due to a pH sensor identified in its structure that was shown before to affect its stability. Here we introduced a new level of control of its hemolytic activity by making a variant with hemolytic activity that was pH-dependent. Based on detailed structural analysis coupled with molecular dynamics and mutational analysis, we found that the bulky side chain of Tyr406 allosterically affects the pH sensor. Molecular dynamics simulation further suggested which other amino acid residues may also allosterically influence the pH-sensor. LLO was engineered to the point where it can, in a pH-regulated manner, perforate artificial and cellular membranes. The single mutant Tyr406Ala bound to membranes and oligomerized similarly to the wild-type LLO, however, the final membrane insertion step was pH-affected by the introduced mutation. We show that the mutant toxin can be activated at the surface of artificial membranes or living cells by a single wash with slightly acidic pH buffer. Y406A mutant has a high potential in development of novel nanobiotechnological applications such as controlled release of substances or as a sensor of environmental pH.


Download here

Back to Overview

Contact Us

Please type your full name.
Invalid email address.
Invalid Input
Invalid Input
Nanion Technologies GmbH

Ganghoferstr. 70A
D-80339 Munich - Germany
info@nanion.de