Interactions between Aquaporin Proteins and Block Copolymer Matrixes

Abstract

This chapter continues to further expand its focus on aquaporins (AQPs) by ofering a general outline on how the AQPs block copolymers, and polymer support structures can interrelate and such connections can be comprehensively classiied and deined. The irst section of the overview will consider the relationship between block copolymers and AQPs. It will also examine the general membrane protein integration into block copolymers, since this can cause AQP-block copolymer complexes in vesicular (proteopolymersomes) as well as in planar forms. The majority of considerations taken into account during AQP incorporation come from the research conducted in relation to the process of incorporating other types of membrane proteins. This chapter includes an overview of the various characterization methodologies needed for the study of proteopolymersomes, as well as freeze-fracture transmission electron microscopy (FF-TEM), luorescence correlation spectroscopy (FCS), small-angle X-ray scatering (SAXS), and stopped-low light scatering (SFLS). The research data presented in this chapter emphasizes the fact that a successful process of membrane fabrication requires the integration of reconstituted AQPs into a suitable supporting matrix formation.Keywords: aquaporin proteins, block copolymer, matrix, vesicular, membrane protein Assessing aquaporin proteins and block copolymer matrixes interactionsMost research performed on membrane protein inclusion has been conducted primarily with lipids as the host matrix components (original proteoliposomes publication on the subject came out in 1971) [1]. Since then, polymer-based incorporation process has received increased atention and the earliest proteopolymersomes publication emerged in 2000 [2]. The initial work stages in this research area concentrated on the inclusion of membranespanning proteins, such as membrane-bound ion channels (ATPases) and bacteriorhodopsin incorporation into polymethyloxazoline-polydimethylsiloxane-polymethyloxazoline (PMOXA-PDMS-PMOXA) triblock copolymer bilayers occurring in planar [3] or vesicular forms [4][5][6]. It is quite fascinating that the membrane proteins may be functionally incorporated into polymeric bilayers (e.g., based on PMOXA-PDMS-PMOXA) that occur up to 10 times thicker than their lipidic counterparts [7]. Moreover, researchers have observed proteopolymersomes with protein density values that drastically surpassed those of proteoliposomes [8]. Research on these phenomena has helped to establish a theoretical approach for generalized membrane protein incorporation into the amphiphilic structures. This methodology is based on the notion that the eiciency of the membrane protein incorporation process relies on its hydrophobicity potential and its coupling capacity to the host membrane is directly connected to the hydrophobic mismatch parameters. In order to reduce this mismatch dynamic, the method calls for the host membrane to be deformed in such a way that it matches the hydrophobic length parameter of the membrane protein's transm...