Xiaojun Zhao

Designer Self-Assembling Peptide Materials

Macromolecular Bioscience, 2007

Molecular self-assembly is ubiquitous in Nature, from lipids that form oil droplets in water, and... more Molecular self-assembly is ubiquitous in Nature, from lipids that form oil droplets in water, and surfactants that form micelles and other complex structures in water, to sophisticated multiunit ribosome and virus assemblies. Nature is a grand master who utilizes the strategy to bottom-up build hierarchical materials. These elegant molecular self-assembly systems lie at the interface between biochemistry, molecular biology, peptide and protein chemistry, macromolecular science, materials science, and engineering. The key elements are chemical

Download

Molecular designer self-assembling peptides

Chemical Society Reviews, 2006

Chemistry has generally been associated with inorganic and organic syntheses, metal-organic compo... more Chemistry has generally been associated with inorganic and organic syntheses, metal-organic composites, coordinate metal chemistry, catalyses, block copolymer, coating, thin film, industrial surfactants and small-molecule drug development. That is about to change. Chemistry will also expand to the discovery and fabrication of biological and molecular materials with diverse structures, functionalities and utilities. The advent of biotechnology, nanotechnology and nanobiotechnology has accelerated this trend. Nature has selected and evolved numerous molecular architectural motifs at nanometer scale over billions of years for particular functions. These molecular nanomotifs can now be designed for new materials and nanodevices from the bottom up. Chemistry will again harness Nature&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s enormous power to benefit other disciplines and society. This tutorial review focuses on two self-assembling peptide systems.

Designer self-assembling peptide nanofiber scaffolds for 3D tissue cell cultures

Seminars in Cancer Biology, 2005

Biomedical researchers have become increasingly aware of the limitations of time-honored conventi... more Biomedical researchers have become increasingly aware of the limitations of time-honored conventional 2D tissue cell cultures where most tissue cell studies have been carried out. They are now searching for 3D cell culture systems, something between a petri dish and a mouse. It has become apparent that 3D cell culture offers a more realistic micro-and local-environment where the functional properties of cells can be observed and manipulated that is not possible in animals. A newly designer self-assembling peptide scaffolds may provide an ideally alternative system. The important implications of 3D tissue cell cultures for basic cell biology, tumor biology, high-content drug screening, and regenerative medicine and beyond could be profound.

Download

Fabrication of molecular materials using peptide construction motifs

Trends in Biotechnology, 2004

Biotechnology has generally been associated with gene cloning and expression, genomics, high thro... more Biotechnology has generally been associated with gene cloning and expression, genomics, high throughput drug discovery, biomedical advancement and agricultural development. That is about to change. Biotechnology will expand to encompass discovery and fabrication of biological and molecular materials with diverse structures, functionalities and utilities. The advent of nanobiotechnology and nanotechnology have accelerated this trend. Analogous to the construction of an intricate architectural structure, diverse and numerous structural motifs are used to assemble a sophisticated complex. Nature has selected, produced and evolved numerous molecular architectural motifs over billions of years for particular functions. These molecular motifs can now be used to build materials from the bottom up. Biotechnology will continue to harness nature&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s enormous power to benefit other disciplines and society as a whole.

Self-Assembling Peptide Detergents Stabilize Isolated Photosystem I on a Dry Surface for an Extended Time

We used a class of designed peptide detergents to stabilize photosystem I (PS-I) upon extended dr... more We used a class of designed peptide detergents to stabilize photosystem I (PS-I) upon extended drying under N 2 on a gold-coated-Ni-NTA glass surface. PS-I is a chlorophyll-containing membrane protein complex that is the primary reducer of ferredoxin and the electron acceptor of plastocyanin. We isolated the complex from the thylakoids of spinach chloroplasts using a chemical detergent. The chlorophyll molecules associated with the PS-I complex provide an intrinsic steady-state emission spectrum between 650 and 800 nm at À196.15 8C that reflects the organization of the pigment-protein interactions. In the absence of detergents, a large blue shift of the fluorescence maxima from approximately 735 nm to approximately 685 nm indicates a disruption in light-harvesting subunit organization, thus revealing chlorophyllÀprotein interactions. The commonly used membrane protein-stabilizing detergents, N-dodecylb-D-maltoside and N-octyl-b-D-glucoside, only partially stabilized the approximately 735-nm complex with approximately 685-nm spectroscopic shift. However, prior to drying, addition of the peptide detergent acetyl-AAAAAAK at increasing concentration significantly stabilized the PS-I complex. Moreover, in the presence of acetyl-AAAAAAK, the PS-I complex is stable in a dried form at room temperature for at least 3 wk. Another peptide detergent, acetyl-VVVVVVD, also stabilized the complex but to a lesser extent. These observations suggest that the peptide detergents may effectively stabilize membrane proteins in the solid-state. These designed peptide detergents may facilitate the study of diverse types of membrane proteins. Citation: Kiley P, Zhao X, Vaughn M, Baldo MA, Bruce BD, et al. (2005) Self-assembling peptide detergents stabilize isolated photosystem I on a dry surface for an extended time. PLoS Biol 3(7): e230.

Download

Self-Assembling Peptide Detergents Stabilize Isolated Photosystem Ion a Dry Surface for an Extended Time

PLOS Biology, 2005

We used a class of designed peptide detergents to stabilize photosystem I (PS-I) upon extended dr... more We used a class of designed peptide detergents to stabilize photosystem I (PS-I) upon extended drying under N 2 on a gold-coated-Ni-NTA glass surface. PS-I is a chlorophyll-containing membrane protein complex that is the primary reducer of ferredoxin and the electron acceptor of plastocyanin. We isolated the complex from the thylakoids of spinach chloroplasts using a chemical detergent. The chlorophyll molecules associated with the PS-I complex provide an intrinsic steady-state emission spectrum between 650 and 800 nm at À196.15 8C that reflects the organization of the pigment-protein interactions. In the absence of detergents, a large blue shift of the fluorescence maxima from approximately 735 nm to approximately 685 nm indicates a disruption in light-harvesting subunit organization, thus revealing chlorophyllÀprotein interactions. The commonly used membrane protein-stabilizing detergents, N-dodecylb-D-maltoside and N-octyl-b-D-glucoside, only partially stabilized the approximately 735-nm complex with approximately 685-nm spectroscopic shift. However, prior to drying, addition of the peptide detergent acetyl-AAAAAAK at increasing concentration significantly stabilized the PS-I complex. Moreover, in the presence of acetyl-AAAAAAK, the PS-I complex is stable in a dried form at room temperature for at least 3 wk. Another peptide detergent, acetyl-VVVVVVD, also stabilized the complex but to a lesser extent. These observations suggest that the peptide detergents may effectively stabilize membrane proteins in the solid-state. These designed peptide detergents may facilitate the study of diverse types of membrane proteins. Citation: Kiley P, Zhao X, Vaughn M, Baldo MA, Bruce BD, et al. (2005) Self-assembling peptide detergents stabilize isolated photosystem I on a dry surface for an extended time. PLoS Biol 3(7): e230.

Download

Designer self-assembling peptide nanofiber scaffolds for 3D tissue cell cultures

Biomedical researchers have become increasingly aware of the limitations of time-honored conventi... more Biomedical researchers have become increasingly aware of the limitations of time-honored conventional 2D tissue cell cultures where most tissue cell studies have been carried out. They are now searching for 3D cell culture systems, something between a petri dish and a mouse. It has become apparent that 3D cell culture offers a more realistic micro-and local-environment where the functional properties of cells can be observed and manipulated that is not possible in animals. A newly designer self-assembling peptide scaffolds may provide an ideally alternative system. The important implications of 3D tissue cell cultures for basic cell biology, tumor biology, high-content drug screening, and regenerative medicine and beyond could be profound.

Download

Uploads

Papers by Xiaojun Zhao

Log In