Development of supported biomimetic membranes for insertion of aquaporin protein water channels for novel water filtration applications

Aquaporins represent a class of membrane protein channels found in all living organisms that selectively transport water molecules across biological membranes. The work presented in this thesis was motivated by the conceptual idea of incorporating aquaporin water channels into biomimetic membranes to develop novel water separation technologies. To accomplish this, it is necessary to construct an efficient platform to handle biomimetic membranes. Moreover, general methods are required to reliable and controllable reconstitute membrane proteins into artificially made model membranes. These are the topics of this thesis, and are divided into three main chapters. Chapter 2 reviews recent advances in the design and construction of biomimetic membrane arrays. Moreover, current and novel strategies for the reconstitution of membrane proteins into biomimetic membranes are reviewed. Chapter 3 presents the development of biomimetic membrane devices suitable of supporting the establishment of functional biomimetic membrane arrays. Furthermore, scaling up the effective membrane area from rectangular 8×8 arrays (64 membranes) to rectangular 24×24 (576 membranes) or hexagonal 24×27 (648 membranes) is demonstrated in a horizontal chamber design. Chapter 4 characterizes reconstitution and folding of E. coli Aquaporin–Z (AqpZ) and the spinach plasma integral protein 2;1 (SoPIP2;1) aquaporins into model membranes. A central part of this chapter is the development of a method for formation of giant protein vesicles (≥10 μm). This constitutes a new methodology to correctly and functionally reconstitute membrane proteins in controllable amounts into giant vesicles. The method for formation of giant protein vesicles subsequently led to the first functional prototype of an aquaporin-membrane water filtration device.