Materials Assembly and Formation Using Engineered Polypeptides

Abstract

▪ Abstract Molecular biomimetics can be defined as mimicking function, synthesis, or structure of materials and systems at the molecular scale using biological pathways. Here, inorganic-binding polypeptides are used as molecular building blocks to control assembly and formation of functional inorganic and hybrid materials and systems for nano- and nanobiotechnology applications. These polypeptides are selected via phage or cell surface display technologies and modified by molecular biology to tailor their binding and multifunctionality properties. The potential of this approach in creating new materials systems with useful physical and biological properties is enormous. This mostly stems from molecular recognition and self-assembly characteristics of the polypeptides plus the added advantage of genetic manipulation of their composition and structure. In this review, we highlight the basic premises of molecular biomimetics, describe the approaches in selecting and engineering inorganic-binding polypeptides, and present examples of their utility as molecular linkers in current and future applications.

Improved peptidyl linkers for self-assembly of semiconductor quantum dot bioconjugates

“…Further, combining these types of linkers in one experiment can allow different orthogonally-targeted biomolecules to be self-assembled with the same QD to create multifunctional probes. Alternatively, switching the peptide sequences to those that recognize other metals or semiconductors can potentially allow selfassembly of similar biomolecules with a variety of other nanoparticle surfaces [30]. Lastly, it is also worth mentioning that several recent studies have suggested that it is possible to self-assemble polyhistidine modified proteins and peptides with commercial QD preparations [31,32].…”

Molecular Biomimetics: Genetic Synthesis, Assembly, and Formation of Materials Using Peptides

“…[61][62][63][64][65] Among the display technologies, the in vivo selection of peptides using cellsurface display (CSD) and phage display (PD) has been used most frequently (Figure 2). 9 CSD is a technology whereby peptides appear on the flagella of a bacterial cell membrane. PD is a technology whereby peptides appear on the coat protein of a phage.…”

“…These approaches have been adapted to select peptides that bind to solid inorganic materials. 1,[3][4][5][6][7][8][9][55][56][57][58][59]66 The articles by Evans et al and Tomczak et al in this issue explain combinatorial mutagenesis, the method of creating a large set of phage or bacteria-each displaying a peptide with a random sequence-and the biopanning process, the method that culls the set to obtain only the peptide sequences that selectively bind The enamel has an architecture of woven enamel rods (3 µm diameter) at the micrometer scale, each rod containing thousands of long HA crystallites (10s of nm thick and several mm long), all spatially and crystallographically well-organized on the nanometer scale.…”

“…The chemical or physical nature of the inorganic substrate may disqualify a particular display technology. For instance, since a centrifugation step is necessary during the biopanning process ( Figure 2b) when one is working with powder substrates, phage display is suitable for finding peptides that bind to powders, [5][6][7][8][9] but the CSD system is not. Centrifuging a bacterial cell with flagella would shear off the flagella and the attached peptides from the cell.…”

“…The peptide fabrication and assembly processes take place under ambient and environmentally friendly conditions. [1][2][3][4][5][6][7][8][9][10][11] Gaining the ability to closely manipulate the behavior of peptides to fully control materials formation would be a giant leap toward realizing nanometer-scale building blocks that tailor electronic, optical, mechanical, or magnetic materials properties. 25 Molecular biology and genetics approaches could modify the polypeptides and their molecular-recognition characteristics, [11][12][13][14][15] and traditional and state-of-the-art engineering approaches 16 could create inorganic or synthetic structures such as nanoparticles, [17][18][19][20] quantum dots, 20 molecular wires 21 or nanowires, 22 or synthetic molecular systems 23 (e.g., organic semiconductors).…”