In vitro Investigation of the MexAB Efflux Pump From Pseudomonas aeruginosa

Alice Verchère (1) , Manuela Dezi , Isabelle Broutin (1) , Martin Picard (2)

1 LCRB - UMR 8015 - Laboratoire de cristallographie et RMN biologiques
2 SMPSD - Système membranaires, photobiologie, stress et détoxication

There is an emerging scientific need for reliable tools for monitoring membrane protein transport. We present a methodology leading to the reconstitution of efflux pumps from the Gram negative bacteria Pseudomonas aeruginosa in a biomimetic environment that allows for an accurate investigation of their activity of transport. Three prerequisites are fulfilled: compartmentation in a lipidic environment, use of a relevant index for transport and generation of a proton gradient. The membrane protein transporter is reconstituted into liposomes together with bacteriorhodopsin, a light-activated proton pump that generates a proton gradient that is robust as well as reversible and tunable. The activity of the protein is deduced from the pH variations occurring within the liposome, using pyranin, a pH-dependent fluorescent probe. We describe a step-by-step procedure where membrane protein purification, liposome formation, protein reconstitution and transport analysis are addressed. Although they were specifically designed for an RND transporter, the described methods could potentially be adapted for use with any other membrane protein transporter energized by a proton gradient.

Mots clés: liposomes; proton gradient; bacteriorhodopsin Date; antibiotic resistance; transport; membrane protein

Domaines: Sciences du Vivant [q-bio]

Alice Verchère, Manuela Dezi, Isabelle Broutin, Martin Picard. In vitro Investigation of the MexAB Efflux Pump From Pseudomonas aeruginosa. Journal of visualized experiments : JoVE, 2014, 84, ⟨10.3791/50894⟩. ⟨hal-02150066⟩