Fabrication of biomolecule–copolymer hybrid nanovesicles as energy conversion systems

Abstract

This work demonstrates the integration of the energy-transducing proteins bacteriorhodopsin (BR) from Halobacterium halobium and cytochrome c oxidase (COX) from Rhodobacter sphaeroides into block copolymeric vesicles towards the demonstration of coupled protein functionality. An ABA triblock copolymer-based biomimetic membrane possessing UV-curable acrylate endgroups was synthesized to serve as a robust matrix for protein reconstitution. BR-functionalized polymers were shown to generate light-driven transmembrane pH gradients while pH gradient-induced electron release was observed from COX-functionalized polymers. Cooperative behaviour observed from composite membrane functionalized by both proteins revealed the generation of microamp-range currents with no applied voltage. As such, it has been shown that the fruition of technologies based upon bio-functionalizing abiotic materials may contribute to the realization of high power density devices inspired by nature.

Vectorial insertion of bacteriorhodopsin for directed orientation assays in various polymeric biomembranes

“…In fact, it was shown that a steric contraction of the hydrophilic components during polymerization was observed as well [21]. Without cross-linking, the 4 nm-thick polymer produced a low activity of bacteriorhodopsin due to the instability of the membrane as well as an inability to prevent transmembrane ion flux [22]. The jDpHj commonly peaked at 30-50 min around to a level around 0.1 (as shown, jDpHjZ 0.0953 at 50 min) and exhibited a large decrease of 57.71% in 2 h. These results indicate that although membrane leakage to ions in non-cross-linked polymer membranes was observed, the polymer membrane stability was far improved over that of the lipid membranes considering the experiments were conducted at room temperature.…”

“…As such, this would have possibly resulted in commonly observed 50/50 monomer orientations to decrease unidirectional pumping capabilities. In addition, polymer shielding effects could have also played a role in light scattering while not allowing the maximum amount of light to reach and activate the protein [21,22]. The shielding effects seemed to be far greater with bacteriorhodopsin monomers compared with polymers containing reconstituted purple membrane.…”

Polymer-Enabled Carbon Nanotube Deposition for Cellular Interrogation Applications

“…We have developed a technology that addresses the requisite strategies towards the fabrication of novel nanoprobe technologies that are capable of non-invasively stimulating or sensing cellular activity with attenuated inflammatory gene program responses. Versatile block copolymer materials that can be functionalized with anti-inflammatories such as dexamethasone, or various proteins, and tailored to possess varying stiffness properties have been developed as biocompatibility-enhancing modalities [6][7][8][9][10][11][12][13]. In addition, their amphiphilic nature enables their Langmuir-Blodgett (LB)-mediated transfer onto substrates for robust interfacing.…”

e‐Beam Nanopatterned Photo‐Responsive Bacteriorhodopsin‐Containing Hydrogels

“…[10,11] Significantly, bR has recently been shown to decrease pH locally. [12,13] This then provides the mechanism of actuation when combined with poly(acrylic acid), a pH-responsive polymer. [1] We chemically conjugated amine-terminated poly(acrylic acid) (PAA-a, depicted by the black monomer structure in Scheme 1) to the EC side of bR, thus orienting the trajectory of proton transport towards the polymer chain.…”