references Chj
Barbas, C. F., D. Hu, N. Dunlop, L. Sawyer, D. Cababa, et al. 1994. In vitro evolution of a neutralizing human antibody to human immunodeficiency virus type 1 to enhance affinity and broaden strain cross-reactivity. Proc Natl Acad Sci U S A 91 3809-13. Barbas, C. F., J. D. Bain, D. M. Hoekstra and R. A. Lerner. 1992. Semisynthetic combinatorial antibody libraries A chemical solution to the diversity problem. Proc Natl Acad Sci U S A 89 4457-61. Bessette, P. H., M. A. Mena, A. W. Nguyen and P....
B Gvu
Phages displaying TCRs with low affinity are washed off Yeast cells with high fluorescence signal in region 1 R1 are collected Yeast cells with high fluorescence signal in region 1 R1 are collected FIGURE 7.3 see color insert following page 178 TCR engineering using A phage display and B yeast display, adapted from Boder and Wittrup 1997 . A phage display library of TCRs is usually screened by panning phage particles on a surface matrix coated with purified pMHC complexes, while a yeast display...
Geometrybased Design
There are two significant limitations to all computational design efforts 1 the extent to which the design criteria theory match reality and 2 the speed with which one can make and test proteins. In the 1990s, when computational protein design was in its infancy, fitness functions to accurately describe molecular interactions and algorithms to search the astronomical number of potential designed proteins were too primitive for the design of complex stereochemical surfaces. Furthermore, the...
Info Qzp
FIGURE 4.5 Comparison in library quality with and without error correction. The fraction of clones in a library that conform to the intended library design drop exponentially with the length of the fragment being diversified. Orange error rates in standard commercially available synthetic oligonucleotides, and fraction of perfect clones when a library is assembled from standard oligonucleotides. Green error rates in synthetic oligonucleotides that have been error-corrected by consensus...
Info Rxc
DNA encoding DNA protein of encoding interest P2A Protein of interest Reiersen et al. 2005 C. M.Haelll fusion protein in compartments DNA DNA encoding encoding protein of M.Haelll interest iC -4-M.HaeM Bertschinger et al. 2007 D. AGT fusion protein in compartments DNA DNA encoding encoding protein of AGT interest Branched f phosphoramidite RNAremaining ft after RNaseH treatment FIGURE 3.3 Selection particles for covalent DNA display. A Multiple methods based on mRNA display have been developed....
Preface
Proteins possess a broad range of structural and functional properties that are unmatched by any other class of biological molecules. Amazingly, nature has arranged simple atoms and chemical bonds in such a way to facilitate complex biological processes like molecular recognition and catalysis. Nature has also inspired many scientists and engineers to design and create their own customized proteins. These engineered proteins can serve as novel molecular tools for scientific, medical, and...
Yeast Surface Display
Yeast surface display physically couples the protein to be engineered to an anchor protein embedded within the yeast cell wall. The eukaryotic secretory pathway of yeast allows a wide variety of proteins to be displayed, including many with complicated folds. Proteins that have been engineered using yeast surface display include scFvs Feldhaus and Siegel 2004 Chao et al. 2006 , Fab antibody fragments Weaver-Feldhaus et al. 2004 , single-chain T-cell receptors scTCRs Shusta et al. 1999 ,...
Info Xlx
FIGuRE 4.2 Codon bias in diversification using mixtures of nucleotides. The bar graphs indicate the number of codons encoding each amino-acid residue and the stop codon when the diversified region is encoded by NNN A vs. NNS or NNK B . 1.E 20 1.E 18 g 1.E 16 1.E 14 jb 1.E 12 1.E 10 1.E 08 1.E 06 1.E 04 1.E 02 1.E 00 FIGuRE 4.3 Number of possible codon combinations encoded by NNS or NNK increases exponentially with the number of codons that are diversified. The boxes show typical ranges in...
Faster 1
The fast and accurate side-chain topology and energy refinement FASTER method Desmet et al. 2002 is a heuristic iterative optimization method inspired by the previous success of the dead-end elimination DEE techniques. It attempts to take advantage of the elimination power of DEE without requiring its large computational run-times, while trading off a certain degree of optimality. In general, it does so by assuming a given rotamer assignment at all but one protein position and then exhaustively...
Design Strategy
The modular protein design strategy is highly versatile and can employ peptide sequences derived from wild-type proteins, computationally guided amino-acid sequences, and or peptide motifs discovered using high-throughput screening Figure 8.2 . While the majority of protein-based materials described to date have used wild-type amino-acid sequences, there are notable examples of engineered sequences as well. For example, high-throughput screening of peptides was used to determine the relative...
Experimental Approaches For Highthroughput Design Sampling
Despite recent advances, the success rate for computer-based protein designs is well below 100 . Therefore, it is important to be able to experimentally characterize as many designs as possible. Typically, this requires cloning the gene for the designed polypeptide in an expression vector to allow subsequent microbial expression and purification for in vitro characterization. This one-protein-at-a-time approach is expensive, tedious, and time consuming. There are two approaches that in the near...
Contents
Contributor Chapter 1 Phage Display Systems for Protein Chapter 2 Cell Surface Display Systems for Protein Engineering 23 Sarah J. Moore, Mark J. Olsen, Jennifer R. Cochran, and Frank V. Cochran Chapter 3 Cell-Free Display Systems for Protein Pamela A. Barendt and Casim A. Sarkar Chapter 4 Library Construction for Protein Dasa Lipovsek, Marco Mena, Shaun M. Lippow, Subhayu Basu, and Brian M. Baynes Chapter 5 Design and Engineering of Synthetic Binding Proteins Using Nonantibody Chapter 6...
the molecular scaffold concept
The idea of constructing a new molecular recognition function through the engineering of a section of protein surface i.e., a patch Figure 5.1A originates from the molecular architecture of immunoglobulins Figure 5.1B . The immune system can produce antibodies against virtually any type of antigen by, to a first-order approximation, simply tuning the amino-acid sequences of a total of six short segments termed complementarity determining regions CDRs . CDRs are surface-exposed loops located at...
mapping binding energetics
Although most phage display studies have focused on either improving natural protein functions or developing novel protein functions, the method can also be used to understand the molecular basis of protein structure and function. Libraries with restricted diversity have proven to be highly effective for studying protein function, because reducing the chemical complexity of the library greatly simplifies the identification of key interactions within a binding interface Morrison and Weiss 2001...
library screening methods
Cell surface display systems are valuable tools for protein engineering when coupled with a method for high-throughput screening of large libraries Boder and Wittrup 1998 Daugherty et al. 1998 . While flow cytometry remains a common method for screening cell surface display libraries, other methods such as magnetic bead sorting and panning have also been developed. The library screening strategies discussed in this section are generally applicable to multiple hosts and display formats....
Grasp
public index.php Software GRASP html probe.php Structural visualization program Structural visualization program Visualization of protein surfaces and electrostatic potential maps GRASP scripts for computing the residual potential Software for computation of steric complementarity the backbone only. These cartoon models are useful for understanding the overall architecture of a protein or protein complex, and thus in identifying particular regions to include as variables in a combinatorial...
Xzsj
Second generation 102 residues, a-helical, well folded Second generation 102 residues, a-helical, well folded FIGuRE 11.5 see color insert following page 178 Design of the first- and second-generation libraries of binary patterned four-helix bundles. The first generation library was designed to have 74 residues. In the second generation, each helix was extended by one helical turn leading to a 102-residue library. The design templates of the first- and second-generation four-helix bundle...
conclusion and future prospects
Protein therapeutics are a very important part of modern medicine, and in certain situations they are the only effective therapies. Expanding with an ever-increasing speed, the protein therapeutics market is projected to reach 87 billion by year 2010 Kalorama Information 2006 . To realize such great potential, continuous efforts are required to optimize their efficacy, while simultaneously discovering novel protein drugs. As exemplified in this chapter, protein engineering and design have long...
Conclusion
Substantial progress has been made in the design of protein structure. Observations from natural proteins and mutagenesis experiments, as well as learning from failed protein design attempts, have guided our current understanding. As these examples illustrate, the iteration between computational design and experimental validation is crucial toward improving our models. The approximations necessary for speed in protein design come at the expense of accuracy, and methods for circumventing these...
case studies
Elastin-like polypeptides have been widely studied as potential injectable biomaterials and implantable scaffolds for regenerative medicine and drug delivery Chilkoti et al. 2002 Rodriguez-Cabello et al. 2007 . Potential applications include cartilage and invertebral disk repair Betre et al. 2006, Betre et al. 2002 , small diameter vascular grafts Liu et al. 2004 , and spinal cord repair Straley and Heilshorn 2009 . Elastin motifs are attractive components of materials for tissue engineering...
Contributor List
Department of Bioengineering University of Pennsylvania Philadelphia, Pennsylvania Codon Devices, Inc. Cambridge, Massachusetts Codon Devices, Inc. Cambridge, Massachusetts Department of Chemistry Princeton University Princeton, New Jersey Biophysics University of North Carolina Chapel Hill, North Carolina Biophysics Graduate Group University of California Berkeley, California and Pharmaceutical Science University of California San Diego, California Department of Chemical Engineering...
Sheldon J Park Jennifer R Cochran
Taylor amp Francis Group, an informa business 6000 Broken Sound Parkway NW, Suite 300 2010 by Taylor and Francis Group, LLC CRC Press is an imprint of Taylor amp Francis Group, an Informa business No claim to original U.S. Government works Printed in the United States of America on acid-free paper 10 9 8 7 6 5 4 3 2 1 International Standard Book Number 978-1-4200-7658-5 Hardback This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made...
Roles Of Interface Topography
Studies of natural interfaces have suggested that the interface topography is a major determinant of protein-protein interaction. The topography of the intended paratope the interface on the antibody binder side that interacts with the epitope is strongly influenced by the choice of scaffold surfaces to be used, and it may be a greater determinant of scaffold capacity than the secondary structure class. The overall shape of a paratope can be convex, flat, or concave. Furthermore, the convex and...
Designing Function
Designing protein function requires consideration of both stability and binding. The task is particularly challenging when designing enzymes. An enzyme not only must bind a target substrate, but also needs to stabilize the transition state and release the product Walsh 2001 . The geometry of catalytic residues must be positioned accurately to support efficiency catalysis. Designed enzymes include catalytic antibodies that are engineered by affinity maturation in the presence of a...
Design Of Preorganized Structures
Although the entropic cost of folding a single chain is less than that required for the intermolecular association of modules, the cost of forming a unique three-dimensional structure from an unconstrained linear chain is still substantial. The unfavorable con-formational entropy change associated with folding into a unique structure can be decreased by preorganizing the desired structure. Several groups have employed this strategy by using covalent cross-links, synthetic templates, or ligand...
Opls
protein molecule, not the water. Using a mean field approach, therefore, we derive the probability PP C of the conformation C of the protein alone by averaging over all possible conformations of the solvent PP C can be expressed mathematically as
References Qhc
Aharoni, A., G. Amitai, K. Bernath, S. Magdassi and D. S. Tawfik. 2005a. High-throughput screening of enzyme libraries Thiolactonases evolved by fluorescence-activated sorting of single cells in emulsion compartments. Chem Biol 12 1281-9. Aharoni, A., A. D. Griffiths and D. S. Tawfik. 2005b. High-throughput screens and selections of enzyme-encoding genes. Curr Opin Chem Biol 9 210-6. Aharoni, A., K. Thieme, C. P. Chiu, S. Buchini, L. L. Lairson, et al. 2006. High-throughput screening...
Flow Cytometry
Flow cytometry allows for the rapid measurement of multiple optical properties of individual cells, particles, or compartmentalized droplets. Fluorescence-activated cell sorting FACS involves the flow cytometric separation of members of the cell population with desired fluorescent properties and is not limited only to cells . Modern FACS instruments are capable of sorting up to 109 cells in one or a few days. Note that these screening capabilities approach the limits of library cloning and...
References Mof
Ajikumar, P. K., K. Tyo, S. Carlsen, O. Mucha, T. H. Phon, et al. 2008. Terpenoids Opportunities for biosynthesis of natural product drugs using engineered microorganisms. Mol Pharm 5 167-90. Asakura, T., K. Nitta, M. Yang, J. Yao, Y. Nakazawa, et al. 2003. Synthesis and characterization of chimeric silkworm silk. Biomacromolecules 4 815-20. Babensee, J. E. 2008. Interaction of dendritic cells with biomaterials. Semin Immunol 20 101-8. Baneyx, F. 1999. Recombinant protein expression in...
Advances In Display Technologies
An important aspect of successful interface design and engineering is the ability to generate and test a large number of amino-acid sequence diversities. Thus, molecular display technologies are an indispensable tool in directed evolution-oriented interface engineering. Phage display Chapter 1 has been the most commonly used display technology in this field. However, other methods such as yeast display Chapter 2 , and ribosome display and mRNA display Chapter 3 have been successfully used. In...
The Binary Code Strategy For Protein Design
The binary code strategy is based on the design of specific patterns of polar and nonpolar amino acids in the primary sequence. The strategy is described as binary because the amino acids are treated as belonging to one of two groups polar or nonpolar. This polar nonpolar patterning is designed to match the inherent structural periodicity of the desired secondary structure a-helix or -strand , and thereby specify amphiphilic units of secondary structure Figure 11.3 . When these amphiphilic...
EMERGING CELL suRFACE DisPLAY systems INsECT CELL AND MAMMALIAN CELL DISPLAY
Insect cell baculovirus display is a well-established technology, yet unlike bacterial or yeast surface display, this system has not been extensively used for protein engineering applications Makela and Oker-Blom 2006 Makela and Oker-Blom 2008 . Despite the relatively few examples of protein engineering with insect cell baculo-virus systems, which require greater expertise in handling compared to microbial-based systems, recent studies have shown much potential. This format involves either the...
CELL suRFACE DisPLAY ouTLooK
Bacterial and yeast surface display are both well-established systems for protein engineering. Continued development of these methods will bring more goals within reach, such as engineering novel enzymes and integral membrane proteins. While currently less developed, insect cell and mammalian cell surface display have the potential to address the limitations of the more established platforms. Efforts that combine protein library screening with computational modeling and bioinformatics methods...