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Journal ArticleDOI

Protein conjugation with genetically encoded unnatural amino acids.

TL;DR: The site-specific incorporation of unnatural amino acids with orthogonal chemical reactivity into proteins enables the synthesis of structurally defined protein conjugates, especially the next-generation protein therapeutics.
About: This article is published in Current Opinion in Chemical Biology.The article was published on 2013-06-01 and is currently open access. It has received 234 citations till now. The article focuses on the topics: Amino acid.
Citations
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Journal ArticleDOI
TL;DR: An emphasis is placed on describing research efforts to overcome the inherent weaknesses of peptide drugs, in particular their poor pharmacokinetic properties, and how these efforts have been critical to the discovery, design, and subsequent development of novel therapeutics.
Abstract: Over the past decade, peptide drug discovery has experienced a revival of interest and scientific momentum, as the pharmaceutical industry has come to appreciate the role that peptide therapeutics can play in addressing unmet medical needs and how this class of compounds can be an excellent complement or even preferable alternative to small molecule and biological therapeutics. In this Perspective, we give a concise description of the recent progress in peptide drug discovery in a holistic manner, highlighting enabling technological advances affecting nearly every aspect of this field: from lead discovery, to synthesis and optimization, to peptide drug delivery. An emphasis is placed on describing research efforts to overcome the inherent weaknesses of peptide drugs, in particular their poor pharmacokinetic properties, and how these efforts have been critical to the discovery, design, and subsequent development of novel therapeutics.

651 citations

Journal ArticleDOI
TL;DR: Combining chemoselective reactions with encoded amino acids has facilitated the installation of posttranslational modifications, as well as rapid derivatization with diverse fluorophores for imaging.
Abstract: Genetic code expansion and reprogramming enable the site-specific incorporation of diverse designer amino acids into proteins produced in cells and animals. Recent advances are enhancing the efficiency of unnatural amino acid incorporation by creating and evolving orthogonal ribosomes and manipulating the genome. Increasing the number of distinct amino acids that can be site-specifically encoded has been facilitated by the evolution of orthogonal quadruplet decoding ribosomes and the discovery of mutually orthogonal synthetase/tRNA pairs. Rapid progress in moving genetic code expansion from bacteria to eukaryotic cells and animals (C. elegans and D. melanogaster) and the incorporation of useful unnatural amino acids has been aided by the development and application of the pyrrolysyl-transfer RNA (tRNA) synthetase/tRNA pair for unnatural amino acid incorporation. Combining chemoselective reactions with encoded amino acids has facilitated the installation of posttranslational modifications, as well as rapid derivatization with diverse fluorophores for imaging.

428 citations

Journal ArticleDOI
TL;DR: Radical Polymerization and Copper(0) Mediated polymerization): From Fundamentals to Bioapplications
Abstract: Radical Polymerization and Copper(0) Mediated Polymerization): From Fundamentals to Bioapplications Cyrille Boyer,*,†,‡ Nathaniel Alan Corrigan,‡ Kenward Jung,‡ Diep Nguyen,‡ Thuy-Khanh Nguyen,‡ Nik Nik M. Adnan,†,‡ Susan Oliver,†,‡ Sivaprakash Shanmugam,‡ and Jonathan Yeow†,‡ †Australian Centre for Nanomedicine, and ‡Centre for Advanced Macromolecular Design (CAMD), School of Chemical Engineering, University of New South Wales, Sydney 2052, Australia

389 citations

Journal ArticleDOI
TL;DR: This review on chemical protein modification through cysteine should appeal to those interested in modifying proteins for a range of applications.
Abstract: The modification of proteins with non-protein entities is important for a wealth of applications, and methods for chemically modifying proteins attract considerable attention. Generally, modification is desired at a single site to maintain homogeneity and to minimise loss of function. Though protein modification can be achieved by targeting some natural amino acid side chains, this often leads to ill-defined and randomly modified proteins. Amongst the natural amino acids, cysteine combines advantageous properties contributing to its suitability for site-selective modification, including a unique nucleophilicity, and a low natural abundance--both allowing chemo- and regioselectivity. Native cysteine residues can be targeted, or Cys can be introduced at a desired site in a protein by means of reliable genetic engineering techniques. This review on chemical protein modification through cysteine should appeal to those interested in modifying proteins for a range of applications.

260 citations

Journal ArticleDOI
TL;DR: One example in which the genetic code itself has been expanded with new building blocks that allow chemists to probe and manipulate the structures and functions of proteins with unprecedented precision is reviewed.
Abstract: Our understanding of the complex molecular processes of living organisms at the molecular level is growing exponentially. This knowledge, together with a powerful arsenal of tools for manipulating the structures of macromolecules, is allowing chemists to to harness and reprogram the cellular machinery in ways previously unimaged. Here we review one example in which the genetic code itself has been expanded with new building blocks that allow us to probe and manipulate the structures and functions of proteins with unprecedented precision.

233 citations

References
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Journal ArticleDOI
TL;DR: In this paper, a set of powerful, highly reliable, and selective reactions for the rapid synthesis of useful new compounds and combinatorial libraries through heteroatom links (C-X-C), an approach called click chemistry is defined, enabled, and constrained by a handful of nearly perfect "springloaded" reactions.
Abstract: Examination of nature's favorite molecules reveals a striking preference for making carbon-heteroatom bonds over carbon-carbon bonds-surely no surprise given that carbon dioxide is nature's starting material and that most reactions are performed in water. Nucleic acids, proteins, and polysaccharides are condensation polymers of small subunits stitched together by carbon-heteroatom bonds. Even the 35 or so building blocks from which these crucial molecules are made each contain, at most, six contiguous C-C bonds, except for the three aromatic amino acids. Taking our cue from nature's approach, we address here the development of a set of powerful, highly reliable, and selective reactions for the rapid synthesis of useful new compounds and combinatorial libraries through heteroatom links (C-X-C), an approach we call "click chemistry". Click chemistry is at once defined, enabled, and constrained by a handful of nearly perfect "spring-loaded" reactions. The stringent criteria for a process to earn click chemistry status are described along with examples of the molecular frameworks that are easily made using this spartan, but powerful, synthetic strategy.

9,069 citations

Journal ArticleDOI
TL;DR: The development of new orthogonal aminoacyl-tRNA synthetase/tRNA pairs has led to the addition of approximately 70 unnatural amino acids to the genetic codes of Escherichia coli, yeast, and mammalian cells, which provide new opportunities to generate proteins with enhanced or novel properties and probes of protein structure and function.
Abstract: The development of new orthogonal aminoacyl-tRNA synthetase/tRNA pairs has led to the addition of approximately 70 unnatural amino acids (UAAs) to the genetic codes of Escherichia coli, yeast, and mammalian cells. These UAAs represent a wide range of structures and functions not found in the canonical 20 amino acids and thus provide new opportunities to generate proteins with enhanced or novel properties and probes of protein structure and function.

1,554 citations

Journal ArticleDOI
20 Apr 2001-Science
TL;DR: A unique transfer RNA/aminoacyl-tRNA synthetase pair has been generated that expands the number of genetically encoded amino acids in Escherichia coli and should provide a general method for increasing the genetic repertoire of living cells to include a variety of amino acids with novel structural, chemical, and physical properties not found in the common 20 amino acids.
Abstract: A unique transfer RNA (tRNA)/aminoacyl-tRNA synthetase pair has been generated that expands the number of genetically encoded amino acids in Escherichia coli. When introduced into E. coli, this pair leads to the in vivo incorporation of the synthetic amino acid O-methyl-l-tyrosine into protein in response to an amber nonsense codon. The fidelity of translation is greater than 99%, as determined by analysis of dihydrofolate reductase containing the unnatural amino acid. This approach should provide a general method for increasing the genetic repertoire of living cells to include a variety of amino acids with novel structural, chemical, and physical properties not found in the common 20 amino acids.

1,495 citations

Journal ArticleDOI
TL;DR: This tutorial review will summarize the history of this emerging field, as well as recent progress in the development and application of bioorthogonal copper-free click cycloaddition reactions.
Abstract: Bioorthogonal chemical reactions are paving the way for new innovations in biology. These reactions possess extreme selectivity and biocompatibility, such that their participating reagents can form covalent bonds within richly functionalized biological systems—in some cases, living organisms. This tutorial review will summarize the history of this emerging field, as well as recent progress in the development and application of bioorthogonal copper-free click cycloaddition reactions.

1,365 citations

Journal ArticleDOI
TL;DR: A bioorthogonal reaction that proceeds with unusually fast reaction rates without need for catalysis: the cycloaddition of s-tetrazine and trans-cyclooctene derivatives, which enables protein modification at low concentration.
Abstract: Described is a bioorthogonal reaction that proceeds with unusually fast reaction rates without need for catalysis: the cycloaddition of s-tetrazine and trans-cyclooctene derivatives. The reactions tolerate a broad range of functionality and proceed in high yield in organic solvents, water, cell media, or cell lysate. The rate of the ligation between trans-cyclooctene and 3,6-di-(2-pyridyl)-s-tetrazine is very rapid (k2 2000 M−1 s−1). This fast reactivity enables protein modification at low concentration.

1,257 citations