New Strategy for Encapsulating Integral Membrane Proteins

University Of California-Davis, Davis CA

Investigators

Abstract

Non-Technical: The PIs goal is to provide a strategy so that the majority of integral membrane proteins (IMPs) could be routinely encapsulated in the nanometer-sized pores of gels for drug discovery, and biotechnology, and energy generation. IMPs are nanometer-size biological workhorses that produce energy, serve as receptors, channels, transporters, and enzymes, when they are embedded in biological membrane hosts. Similarly, nanoporous gels and glasses are mainstays of modern technology because of their unique photochemical, optical, and catalytic properties. PIs IMP-containing bio-functional gels will combine these unique functionalities: e.g. the gel (for solar energy capture) and the IMP for energy absorption from a broader spectrum of wavelengths. They will study nanolipoprotein particles (NLPs) as the biological membrane hosts of IMPs entrapped in inorganic and organic nanoporous gels. NLPs are disc-shaped 10-25 nanometer-sized lipid bilayer patches stabilized by a belt of scaffold proteins. The NLP approach represents a major breakthrough because NLPs fit precisely into the 5-50 nanometer-sized pores of the gels and NLPs serve as a robust host for any IMP so that all components remain functional. On the training side, engineering undergraduates and graduate students working on this project will gain valuable experience that will prepare them for new careers that integrate materials science with biotechnology. Following previous success the PIs will organize a second international workshop "Biomembrane Frontiers: Nanostructures, Models, and the Design of Life: II". Further, they will publish a Tutorial Review on "Creating and Characterizing Biomembrane/Materials Interfaces". Technical: Integral membrane proteins (IMPs) require a lipid membrane host and carry out a number of useful biological functions that could be harnessed by routine encapsulation in mesoporous sol-gel materials. The PIs will study nanolipoprotein particles (NLPs) as the biological membrane hosts of IMPs entrapped in inorganic and organic mesoporous sol-gels. NLPs are soluble discoidal 10-25 nm-sized particles comprised of a lipid bilayer patch stabilized by a belt of apolipoprotein scaffold proteins that can be formed through in vitro self-assembly. NLPs fit precisely into the 5-50 nm-sized pores of the gels and NLPs serve as robust hosts for IMPs, therefore all components may retain their structures and functions. Exploration of the parameters of nanoscale confinement and chemical environment in relation to dynamics, structure, and function of the NLP and IMP-NLP are important from a scientific standpoint as well as toward imagining and optimizing any future applications. Characterization of these parameters will take place with integrated studies employing state-of-the-art dynamic TEM, electron paramagnetic resonance, NMR, circular dichroism, and fluorimetry. Materials Science and Chemical Engineering undergraduates and graduate students working on this project will receive valuable interdisciplinary training in new cell biological and bioengineering techniques, i.e. cell free expression, in the context of production of a functional biocomposite sol-gel materials. The PIs will organize an international workshop, "Biomembrane Frontiers: Nanostructures, Models, and the Design of Life: II" and publish an Instructional Review on "Creating and Characterizing Biomembrane/Materials Interfaces". In the education arena, PIs will provide special topical freshman seminars on Biomaterials.