In situ monitoring of membrane protein insertion into block copolymer vesicle membranes and their spreading via potential-assisted approach

20/05/2020
  Method Copyright: © ACS Applied Materials & Interfaces Scheme 1: Generation of synthosomes on gold electrodes via potential-assisted spreading using the outer membrane protein FhuA

A new approach to produce solid-supported biomimetic membranes via potential-assisted vesicle spreading was developed.

Transmembrane proteins incorporated in solid-supported hybrid membranes can act as selective transporters or used for catalysis. The hydrophobic region of transmembrane proteins allows their incorporation into polymer membranes. The triblock copolymer poly(2-methyl oxazoline)-blockpoly(dimethylsiloxane)-block-poly(2-methyl oxazoline) and an engineered variant of the outer membrane protein Ferric hydroxamate uptake protein component A (FhuA) were used for the potential-assisted spreading of synthosomes on gold electrodes. FhuA lacking the cork domain (FhuA ∆1-160) was a useful candidate to achieve large passive diffusion channels in synthosomes. Isothermal titration calorimetry was used to analyze the insertion of FhuA into the polymer vesicles. The charge of the polymer was used to spread FhuA-containing vesicles on electrodes by electrostatic interactions. The potential-assisted vesicle spreading system was shown to produce homogenous synthosomes more efficiently than common spin- and dip-coating techniques. Functionality of the spread synthosomes was analyzed by passive ion transport response and through electrochemical impedance spectroscopy analysis. Solid-supported biomimetic membranes formed via potential-assisted spreading could be an interesting system for the development of new biosensors and as useful pores for drug delivery and water purification.

Subgroup: Hybrid catalysis & HTS

Funding: Alexander von Humboldt-Stiftung
China Scholarship Council (CSC No. 201306350039)
BMBF-Forschertandem “Chiral Membranes” (Förderkennzeichen:031A164 und 031B0559)
EU and the federal state of North Rhine–Westphalia (grant EFRE 30 00 883 02)
Fraunhofer High Performance Center for Functional lntegration in Materials

T. Mirzaei Garakani, Z. Liu, U. Glebe, J. Gehrmann, J. Lazar, M. A. S. Mertens, M. Möller, N. Hamzelui, L. Zhu, U. Schnakenberg, A. Böker, U. Schwaneberg, ACS Applied Materials & Interfaces, 2019, DOI:10.1021/acsami.9b09302