151
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Vázquez-Dorbatt V, Tolstyka ZP, Maynard HD. Synthesis of Aminooxy End-functionalized pNIPAAm by RAFT Polymerization for Protein and Polysaccharide Conjugation. Macromolecules 2009; 42:7650-7656. [PMID: 21544220 DOI: 10.1021/ma9013803] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A Boc-protected aminooxy end-functionalized poly(N-isopropylacrylamide) (pNIPAAm) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. The monomer was polymerized in the presence of a Boc-protected aminooxy trithiocarbonate chain transfer agent (CTA) utilizing 2,2'-azobis(2-isobutyronitrile) (AIBN) as the initiator in DMF at 70 °C. The final polymer had a number-average molecular weight (M(n)) of 4,200 Da as determined by (1)H NMR spectroscopy and a narrow polydispersity index (1.14) by gel permeation chromatography (GPC). The Boc group was removed, and the polymer was then incubated with N(ε)-levulinyl lysine-modified bovine serum albumin (BSA). Gel electrophoresis confirmed that the conjugation was successful. The aminooxy end-functionalized pNIPAAm was also immobilized on a gold surface after reduction of the trithiocarbonate end-group. The pNIPAAm surface was then incubated with an aldehyde-modified heparin to yield the polysaccharide-functionalized surface. All surface modifications were monitored by FT-IR spectroscopy.
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Affiliation(s)
- Vimary Vázquez-Dorbatt
- Department of Chemistry & Biochemistry and California Nanosystems Institute, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569
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152
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Shi W, Dolai S, Averick S, Fernando SS, Saltos JA, L’Amoreaux W, Banerjee P, Raja K. A General Methodology Toward Drug/Dye Incorporated Living Copolymer−Protein Hybrids: (NIRF Dye-Glucose) Copolymer−Avidin/BSA Conjugates as Prototypes. Bioconjug Chem 2009; 20:1595-601. [DOI: 10.1021/bc900142y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Wei Shi
- The City University of New York at College of Staten Island, NewYork
| | - Sukanta Dolai
- The City University of New York at College of Staten Island, NewYork
| | - Saadyah Averick
- The City University of New York at College of Staten Island, NewYork
| | - Suraj S. Fernando
- The City University of New York at College of Staten Island, NewYork
| | - Jose A. Saltos
- The City University of New York at College of Staten Island, NewYork
| | | | - Probal Banerjee
- The City University of New York at College of Staten Island, NewYork
| | - Krishnaswami Raja
- The City University of New York at College of Staten Island, NewYork
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153
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Dirks A(TJ, Cornelissen JJLM, Nolte RJM. Monitoring Protein−Polymer Conjugation by a Fluorogenic Cu(I)-Catalyzed Azide−Alkyne 1,3-Dipolar Cycloaddition. Bioconjug Chem 2009; 20:1129-38. [DOI: 10.1021/bc8004667] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- A. (Ton) J. Dirks
- Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED, Nijmegen, The Netherlands
| | - Jeroen J. L. M. Cornelissen
- Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED, Nijmegen, The Netherlands
| | - Roeland J. M. Nolte
- Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED, Nijmegen, The Netherlands
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154
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Ariga K, Ji Q, Hill JP, Kawazoe N, Chen G. Supramolecular approaches to biological therapy. Expert Opin Biol Ther 2009; 9:307-20. [PMID: 19216620 DOI: 10.1517/14712590802715772] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Supramolecular chemistry is a useful methodology for construction of nano- or micro-sized objects and can significantly contribute to nanotechnology through so-called bottom-up processing. In addition, supramolecular self-assembled structures can mimic some aspects of biological systems. Bio-related functions such as molecular sensing, controlled release, signaling and materials separations have been realized. Supramolecular chemistry is a multidisciplinary field that includes subjects such as molecular design and nanosized materials. In this article recent examples of supramolecular chemistry in the context of biological therapy are introduced and classified into five categories: small supramolecular systems; designer polymers; self-assembled structures; predesigned assemblies; and nanomaterials. Finally, hierarchic organization of supramolecular structures for advanced functions is introduced to illustrate future directions of investigation. We hope that scientists studying therapeutic applications receive inspiration from this review to exploit the opportunities offered by supramolecular chemistry in their respective research areas.
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Affiliation(s)
- Katsuhiko Ariga
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan.
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155
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Nagorny P, Fasching B, Li X, Chen G, Aussedat B, Danishefsky SJ. Toward fully synthetic homogeneous beta-human follicle-stimulating hormone (beta-hFSH) with a biantennary N-linked dodecasaccharide. synthesis of beta-hFSH with chitobiose units at the natural linkage sites. J Am Chem Soc 2009; 131:5792-9. [PMID: 19341309 PMCID: PMC2756579 DOI: 10.1021/ja809554x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A highly convergent synthesis of the sialic acid-rich biantennary N-linked glycan found in human glycoprotein hormones and its use in the synthesis of a fragment derived from the beta-domain of human Follicle-Stimulating Hormone (hFSH) are described. The synthesis highlights the use of the Sinay radical glycosidation protocol for the simultaneous installation of both biantennary side-chains of the dodecasaccharide as well as the use of glycal chemistry to construct the tetrasaccharide core in an efficient manner. The synthetic glycan was used to prepare the glycosylated 20-27aa domain of the beta-subunit of hFSH under a Lansbury aspartylation protocol. The proposed strategy for incorporating the prepared N-linked dodecasaccharide-containing 20-27aa domain into beta-hFSH subunit was validated in the context of a model system, providing protected beta-hFSH subunit functionalized with chitobiose at positions 7 and 24.
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Affiliation(s)
- Pavel Nagorny
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Bernhard Fasching
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Xuechen Li
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Gong Chen
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Baptiste Aussedat
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Samuel J. Danishefsky
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
- Department of Chemistry, Columbia University, Havemeyer Hall, 3000 Broadway, New York, New York 10027
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156
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Kan C, Trzupek JD, Wu B, Wan Q, Chen G, Tan Z, Yuan Y, Danishefsky SJ. Toward homogeneous erythropoietin: chemical synthesis of the Ala1-Gly28 glycopeptide domain by "alanine" ligation. J Am Chem Soc 2009; 131:5438-43. [PMID: 19334679 PMCID: PMC2765573 DOI: 10.1021/ja808707w] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Ala(1)-Gly(28) glycopeptide fragment (28) of EPO was prepared by chemical synthesis as a single glycoform. Key steps in the synthesis include attachment of a complex dodecasaccharide (7) to a seven amino acid peptide via Lansbury aspartylation, native chemical ligation to join peptide 19 with the glycopeptide domain 18, and a selective desulfurization at the ligation site to reveal the natural Ala(19). This glycopeptide fragment (28) contains both the requisite N-linked dodecasaccharide and a C-terminal (alpha)thioester handle, the latter feature permitting direct coupling with a glycopeptide fragment bearing N-terminal Cys(29) without further functionalization.
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Affiliation(s)
- Cindy Kan
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - John D. Trzupek
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Bin Wu
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Qian Wan
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Gong Chen
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Zhongping Tan
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Yu Yuan
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
| | - Samuel J. Danishefsky
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, New York 10065
- Department of Chemistry, Columbia University, Havemeyer Hall, 3000 Broadway, New York, New York 10027
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157
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Abstract
Erythropoiesis stimulating agents (ESAs) are the main tool to achieve anemia correction in CKD patients. At present six different ESAs are available: epoetin alpha, epoetin beta, epoetin omega, epoetin delta, darbepoetin alpha, and very recently CERA. From one side the patent of older ESAs have expired, and biosimilars (for the moment only of epoetin alpha) have been approved for use in Europe by the European Medicines Agency. However, a number of issues about bioequivalence and how to test it are still to be solved completely. In the mean time pharmaceutical research has kept on working, developing new ESAs and alternative strategies for stimulating erythropoiesis. In this review we present and discuss these points.
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158
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Heredia KL, Grover GN, Tao L, Maynard HD. Synthesis of Heterotelechelic Polymers for Conjugation of Two Different Proteins. Macromolecules 2009; 42:2360-2367. [PMID: 25378715 DOI: 10.1021/ma8022712] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this report we describe a straightforward approach to synthesize polymers with end-groups that bind site-specifically to two different proteins. Telechelic biotin, maleimide poly(N-isopropylacrylamide) (pNIPAAm) was synthesized for the formation of streptavidin (SAv)-bovine serum albumin (BSA) polymer conjugates. Reversible addition-fragmentation chain transfer (RAFT) polymerization of NIPAAm was conducted in the presence of biotinylated chain transfer agents (CTAs) with either ester or amide linkages, and the resultant α-biotinylated pNIPAAm were formed with low polydispersity indices (PDI ≤ 1.09). UV-Vis analysis of the trithiocarbonate chain-ends indicated 88% or greater retention of the group. A maleimide was introduced to the ω chain-end via a radical cross-coupling reaction with a functionalized azo-initiator. The polymer structures were characterized by 1H NMR spectroscopy and gel permeation chromatography (GPC). The resultant biotin-maleimide heterotelechelic polymer was used to form a SAv-BSA heterodimer conjugate. Bioconjugate formation was confirmed by gel electrophoresis.
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Affiliation(s)
- Karina L Heredia
- Department of Chemistry and Biochemistry and the California NanoSystems Institute University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569
| | - Gregory N Grover
- Department of Chemistry and Biochemistry and the California NanoSystems Institute University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569
| | - Lei Tao
- Department of Chemistry and Biochemistry and the California NanoSystems Institute University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569
| | - Heather D Maynard
- Department of Chemistry and Biochemistry and the California NanoSystems Institute University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569
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159
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Flavell RR, Muir TW. Expressed protein ligation (EPL) in the study of signal transduction, ion conduction, and chromatin biology. Acc Chem Res 2009; 42:107-16. [PMID: 18939858 DOI: 10.1021/ar800129c] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Expressed protein ligation (EPL) is a semisynthetic technique in which a recombinant protein thioester, generated by thiolysis of an intein fusion protein, is reacted with a synthetic or recombinant peptide with an N-terminal cysteine to produce a native peptide bond. This method has been used extensively for the incorporation of biophysical probes, unnatural amino acids, and post-translational modifications in proteins. In the 10 years since this technique was developed, the applications of EPL to studying protein structure and function have grown ever more sophisticated. In this Account, we review the use of EPL in selected systems in which substantial mechanistic insights have recently been gained through the use of the semisynthetic protein derivatives. EPL has been used in many studies to unravel the complexity of signaling networks and subcellular trafficking. Herein, we highlight this application to two different systems. First, we describe how phosphorylated or otherwise modified proteins in the TGF-beta signaling network were prepared and how they were applied to understanding the complexities of this pathway, from receptor activation to nuclear import. Second, Rab-GTPases are multiply modified with lipid derivatives, and EPL-based techniques were used to incorporate these modifications, allowing for the elucidation of the biophysical basis of membrane association and dissociation. We also review the use of EPL to understand the biology of two other systems, the potassium channel KcsA and histones. EPL was used to incorporate d-alanine and an amide-to-ester backbone modification in the selectivity filter of the KcsA potassium channel, providing insight into the mechanism of selectivity in ion conduction. In the case of histones, which are among the most heavily post-translationally modified proteins, the modifications play a key role in the regulation of gene transcription and chromatin structure. We describe how native chemical ligation and EPL were used to generate acetylated, phosphorylated, methylated, and ubiquitylated histones and how these modified histones were used to interrogate chromatin biology. Collectively, these studies demonstrate the utility of EPL in protein science. These techniques and concepts are applicable to many other systems, and ongoing advances promise to extend this semisynthetic technique to increasingly complex biological problems.
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Affiliation(s)
- Robert R. Flavell
- Laboratory of Synthetic Protein Chemistry, The Rockefeller University, New York, New York 10065
| | - Tom W. Muir
- Laboratory of Synthetic Protein Chemistry, The Rockefeller University, New York, New York 10065
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160
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161
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Gonnelli M, Strambini GB. No effect of covalently linked poly(ethylene glycol) chains on protein internal dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1794:569-76. [PMID: 19150514 DOI: 10.1016/j.bbapap.2008.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/10/2008] [Accepted: 12/08/2008] [Indexed: 10/21/2022]
Abstract
Poly(ethylene glycol) or PEG is a hydrophilic polymer that covalently linked to therapeutical proteins may significantly increase their pharmacological properties. Despite the extensive production of PEG-conjugated proteins the effects of the polymer on the protein structure and dynamics is poorly understood, making the production of active biomaterials a largely unpredictable process. The present investigation examines the effects of 5 k and 20 k PEG on the internal flexibility of Ribonuclease T1, the mutant C112S of azurin from Pseudomonas aeruginosa, alcohol dehydrogenase and alkaline phosphatase, native and Zn-depleted. These systems encompass structural domains that range from rather superficial, flexible sites to deeply buried, rigid cores. The approach is based on three sensitive parameters related to the phosphorescence emission of internal Trp residues, namely, the intrinsic room-temperature phosphorescence lifetime (tau(0)) that reports on the local flexibility of the protein matrix around the chromophore and the bimolecular rate constant (k(q)) for the quenching of phosphorescence by O(2) and by acrylamide in solution, which are related to the diffusion of these solutes through the protein fold. The results obtained by these three independent, intrinsic probes of protein structure-dynamics concur that mono-PEGylation does not detectably perturb the conformation and dynamics of the protein native fold, over a wide temperature range. The implication is that protein motions are essentially not coupled to the polymer and that adverse effects of chemical modification on biological function are presumably owed to steric hindrance by PEG units blocking the access to sites critical for molecular recognition.
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Affiliation(s)
- Margherita Gonnelli
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche, via Moruzzi 1, 56124 Pisa, Italy
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162
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Hackenberger C, Schwarzer D. Chemoselektive Ligations- und Modifikationsstrategien für Peptide und Proteine. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801313] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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163
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Hackenberger C, Schwarzer D. Chemoselective Ligation and Modification Strategies for Peptides and Proteins. Angew Chem Int Ed Engl 2008; 47:10030-74. [DOI: 10.1002/anie.200801313] [Citation(s) in RCA: 651] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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164
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Abstract
Since the isolation and purification of erythropoietin (EPO) in 1977, the essential role of EPO for mature red blood cell production has been well established. The cloning of the EPO gene and production of recombinant human EPO led to the widespread use of EPO in treating patients with anaemia. However, the biological activity of EPO is not restricted to regulation of erythropoiesis. EPO receptor (EPOR) expression is also found in endothelial, brain, cardiovascular and other tissues, although at levels considerably lower than that of erythroid progenitor cells. This review discusses the survival and proliferative activity of EPO that extends beyond erythroid progenitor cells. Loss of EpoR expression in mouse models provides evidence for the role of endogenous EPO signalling in nonhaematopoietic tissue during development or for tissue maintenance and/or repair. Determining the extent and distribution of receptor expression provides insights into the potential protective activity of EPO in brain, heart and other nonhaematopoietic tissues.
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165
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Affiliation(s)
- Jeet Kalia
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706-1544, USA
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166
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Ho KM, Mao X, Gu L, Li P. Facile route to enzyme immobilization: core-shell nanoenzyme particles consisting of well-defined poly(methyl methacrylate) cores and cellulase shells. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11036-11042. [PMID: 18788820 DOI: 10.1021/la8016529] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A one-step method for preparing cellulase-immobilized nanoparticles that consist of well-defined poly(methyl methacrylate) (PMMA) cores and cellulase shells has been developed. The core-shell nanoparticles are synthesized from a direct graft copolymerization of methyl methacrylate (MMA) from cellulase in an aqueous medium. Particle formation strongly depends on the surface nature of the cellulase (e.g., pH of reaction media) and MMA to cellulase weight ratio. Under optimized conditions, high MMA conversions (>90%) were achieved, and the PMMA-cellulase nanoparticles produced were very stable with narrow size distributions ( Dv/Dn < 1.20). Particle sizes in the range between 80 and 124 nm (volume average diameter) could be tailored by a variation of cellulase concentration. Transmission electron microscopy micrographs revealed that the nanoparticle had a well-defined PMMA core which was evenly coated with cellulase shell. Study of cellulase activity of the PMMA-cellulase nanoparticles indicated that even though activity of immobilized cellulase on the nanoparticles was 41% less than that of the native cellulase after the polymerization, the immobilized cellulase showed improved properties such as broader working pH range and better thermal stability. Other important advantages of this approach include that the PMMA-cellulase nanoparticles could be produced in high concentrations (up to 18% w/w solids content) and the nanoparticles have thick and evenly distributed enzyme shells. Thus, this method may provide a new commercially viable route to the immobilization of thermally stable enzyme to form nanoenzyme particles.
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Affiliation(s)
- Kin Man Ho
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, People's Republic of China
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167
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Abstract
This tutorial review outlines the modern ligation methods that enable the efficient total chemical synthesis of enzymes and other protein molecules. Key to this success is the chemoselective reaction of unprotected synthetic peptides ('chemical ligation'). Notably, native chemical ligation enables the reaction of two unprotected peptides in aqueous solution at neutral pH to form a single product in near quantitative yield. Full-length synthetic polypeptides are folded to form the defined tertiary structure of the target protein molecule, which is characterized by mass spectrometry, NMR, and X-ray crystallography, in addition to biochemical and/or biological activity.
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Affiliation(s)
- Stephen B H Kent
- Department of Chemistry, Institute for Biophysical Dynamics, Center for Integrative Science, University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA.
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168
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169
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Abstract
We present a new design of peptide-polymer conjugates where a polymer chain is covalently linked to the side chain of a helix bundle-forming peptide. The effect of conjugated polymer chains on the peptide structure was examined using a de novo designed three-helix bundle and a photoactive four-helix bundle. Upon attachment of poly(ethylene glycol) to the exterior of the coiled-coil helix bundle, the peptide secondary structure was stabilized and the tertiary structure, that is, the coiled-coil helix bundle, was retained. When a heme-binding peptide as an example is used, the new peptide-polymer conjugate architecture also preserves the built-in functionalities within the interior of the helix bundle. It is expected that the conjugated polymer chains act to mediate the interactions between the helix bundle and its external environment. Thus, this new peptide-polymer conjugate design strategy may open new avenues to macroscopically assemble the helix bundles and may enable them to function in nonbiological environments.
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Affiliation(s)
- Jessica Y. Shu
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720
| | - Cen Tan
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720
| | - William F. DeGrado
- Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Ting Xu
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720
- Department of Chemistry, University of California, Berkeley, California 94720
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
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170
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Casi G, Roelfes G, Hilvert D. Selenoglutaredoxin as a Glutathione Peroxidase Mimic. Chembiochem 2008; 9:1623-31. [DOI: 10.1002/cbic.200700745] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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171
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Li M, De P, Gondi SR, Sumerlin BS. Responsive Polymer‐Protein Bioconjugates Prepared by RAFT Polymerization and Copper‐Catalyzed Azide‐Alkyne Click Chemistry. Macromol Rapid Commun 2008. [DOI: 10.1002/marc.200800073] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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172
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Abstract
The use of synthetic molecules to modulate and track biological events is a central component of chemical biology. As a result, the precise, covalent modification of biomolecules is a key goal for this field. Several strategies have emerged that allow specific tailoring of polypeptides through either endogenous residues or introduced functionality. This tutorial review discusses these recent advances in the context of in vitro and in vivo applications.
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Affiliation(s)
- Isaac S Carrico
- Department of Chemistry, Stony Brook University, 1 John S. Toll Road, Stony Brook, NY 11790-3400, USA.
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173
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Gauthier MA, Klok HA. Peptide/protein-polymer conjugates: synthetic strategies and design concepts. Chem Commun (Camb) 2008:2591-611. [PMID: 18535687 DOI: 10.1039/b719689j] [Citation(s) in RCA: 378] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This feature article provides a compilation of tools available for preparing well-defined peptide/protein-polymer conjugates, which are defined as hybrid constructs combining (i) a defined number of peptide/protein segments with uniform chain lengths and defined monomer sequences (primary structure) with (ii) a defined number of synthetic polymer chains. The first section describes methods for post-translational, or direct, introduction of chemoselective handles onto natural or synthetic peptides/proteins. Addressed topics include the residue- and/or site-specific modification of peptides/proteins at Arg, Asp, Cys, Gln, Glu, Gly, His, Lys, Met, Phe, Ser, Thr, Trp, Tyr and Val residues and methods for producing peptides/proteins containing non-canonical amino acids by peptide synthesis and protein engineering. In the second section, methods for introducing chemoselective groups onto the side-chain or chain-end of synthetic polymers produced by radical, anionic, cationic, metathesis and ring-opening polymerization are described. The final section discusses convergent and divergent strategies for covalently assembling polymers and peptides/proteins. An overview of the use of chemoselective reactions such as Heck, Sonogashira and Suzuki coupling, Diels-Alder cycloaddition, Click chemistry, Staudinger ligation, Michael's addition, reductive alkylation and oxime/hydrazone chemistry for the convergent synthesis of peptide/protein-polymer conjugates is given. Divergent approaches for preparing peptide/protein-polymer conjugates which are discussed include peptide synthesis from synthetic polymer supports, polymerization from peptide/protein macroinitiators or chain transfer agents and the polymerization of peptide side-chain monomers.
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Affiliation(s)
- Marc A Gauthier
- Ecole Polytechnique Fédérale de Lausanne, Institut des Matériaux, Laboratoire des Polymères, Bâtiment MXD, Station 12, CH-1015, Lausanne, Switzerland
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174
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Hiroyuki Y, Toshiyuki S, Takaaki A, Masaki K, Hisao N, Motoo Y. Modification of protein with BGL06, a novel branched oligoglycerol derivative. Biochim Biophys Acta Gen Subj 2008; 1780:680-6. [DOI: 10.1016/j.bbagen.2007.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 11/19/2007] [Accepted: 12/07/2007] [Indexed: 10/22/2022]
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175
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Gamblin DP, van Kasteren SI, Chalker JM, Davis BG. Chemical approaches to mapping the function of post-translational modifications. FEBS J 2008; 275:1949-59. [DOI: 10.1111/j.1742-4658.2008.06347.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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176
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Vadas O, Hartley O, Rose K. Characterization of new multimeric erythropoietin receptor agonists. Biopolymers 2008; 90:496-502. [DOI: 10.1002/bip.20959] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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177
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Foley RN. Erythropoietin: physiology and molecular mechanisms. Heart Fail Rev 2008; 13:405-14. [PMID: 18236154 DOI: 10.1007/s10741-008-9083-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Accepted: 01/08/2008] [Indexed: 12/31/2022]
Abstract
Erythropoietin, the primary regulator of erythropoiesis, is produced by the kidney and levels vary inversely with oxygen availability. Hypoxia-inducible factor-1 (HIF-1), a major transcriptional regulator of several hypoxia-sensitive genes, including erythropoietin, is functionally deactivated by oxygen in a reaction catalyzed by prolyl hydroxylase. Erythropoietin acts by binding to a specific trans-membrane dimeric receptor which has been found in erythroid and non-erythroid cell types. The interaction between erythropoietin and its receptor ultimately leads to conformational change and phosphorylation of the receptor and expression of genes coding for proteins that are anti-apoptotic. Development of erythropoietin stimulating agents is an area of active research. To date, research has focused on activating the erythropoietin receptor, prevention of HIF-1 inactivation, and gene therapy. Even with biologically effective therapies, defining appropriate hemoglobin targets remains challenging. For example, despite decades of clinical trials, target hemoglobin levels in chronic kidney disease remain uncertain, as hemoglobin targets above 13 g/dl have been associated with both benefit (quality of life) and harm (cardiovascular events).
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Affiliation(s)
- Robert N Foley
- Chronic Disease Research Group, 914 South 8th Street, Suite D-253, Minneapolis, MN 55404, USA.
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178
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Olschewski D, Becker CFW. Chemical synthesis and semisynthesis of membrane proteins. MOLECULAR BIOSYSTEMS 2008; 4:733-40. [DOI: 10.1039/b803248c] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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179
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Macdougall IC. Novel Erythropoiesis-Stimulating Agents: A New Era in Anemia Management. Clin J Am Soc Nephrol 2007; 3:200-7. [DOI: 10.2215/cjn.03840907] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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180
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Abstract
AbstractErythropoietin (EPO) is one of the main cytokines involved in the regulation of erythropoiesis. The main site of EPO production are the kidneys. An altered EPO production leads to pathological conditions such as anemia and polycythaemia. Due to the progressive loss of renal peritubular cells, patients with chronic kidney disease (CKD) have low EPO plasma levels. This decreases erythron stimulation with the direct consequence of developing anemia. Before the introduction in the clinical practice of rHuEpo, in the late 1980s, the only solution for treating this type of anemia were blood transfusions and anabolic steroids. Even rHuEpo has proven to be safe and effective for treatment of anemias, there are some concerns about its cost, the need for frequent parenteral administration, and development of anti-EPO antibodies. These inconveniences prompted the search for novel erythropoiesis stimulating agents. Different strategies lead to isolation or chemical synthesis of such agents as darbepoetin alfa and EPO mimetics. In this review, we present some general aspects of EPO biology, with emphasis on chronic renal failure, and expose some of the alternatives to EPO used for anemia correction.
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181
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Hodges VM, Rainey S, Lappin TR, Maxwell AP. Pathophysiology of anemia and erythrocytosis. Crit Rev Oncol Hematol 2007; 64:139-58. [PMID: 17656101 DOI: 10.1016/j.critrevonc.2007.06.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 03/02/2007] [Accepted: 06/12/2007] [Indexed: 10/23/2022] Open
Abstract
An increasing understanding of the process of erythropoiesis raises some interesting questions about the pathophysiology, diagnosis and treatment of anemia and erythrocytosis. The mechanisms underlying the development of many of the erythrocytoses, previously characterised as idiopathic, have been elucidated leading to an increased understanding of oxygen homeostasis. Characterisation of anemia and erythrocytosis in relation to serum erythropoietin levels can be a useful addition to clinical diagnostic criteria and provide a rationale for treatment with erythropoiesis stimulating agents (ESAs). Recombinant human erythropoietin as well as other ESAs are now widely used to treat anemias associated with a range of conditions, including chronic kidney disease, chronic inflammatory disorders and cancer. There is also heightened awareness of the potential abuse of ESAs to boost athletic performance in competitive sport. The discovery of erythropoietin receptors outside of the erythropoietic compartment may herald future applications for ESAs in the management of neurological and cardiac diseases. The current controversy concerning optimal hemoglobin levels in chronic kidney disease patients treated with ESAs and the potential negative clinical outcomes of ESA treatment in cancer reinforces the need for cautious evaluation of the pleiotropic effects of ESAs in non-erythroid tissues.
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Affiliation(s)
- Vivien M Hodges
- Haematology Research Group, Centre for Cancer Research and Cell Biology, Queen's University, Belfast, United Kingdom.
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182
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Miranda LP, Shao H, Williams J, Chen SY, Kong T, Garcia R, Chinn Y, Fraud N, O'Dwyer B, Ye J, Wilken J, Low DE, Cagle EN, Carnevali M, Lee A, Song D, Kung A, Bradburne JA, Paliard X, Kochendoerfer GG. A Chemical Approach to the Pharmaceutical Optimization of an Anti-HIV Protein. J Am Chem Soc 2007; 129:13153-9. [DOI: 10.1021/ja073982h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Les P. Miranda
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Haiyan Shao
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Jason Williams
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Shiah-Yun Chen
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Ting Kong
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Rod Garcia
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Yvonne Chinn
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Nathalie Fraud
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Bill O'Dwyer
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Jay Ye
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Jill Wilken
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Donald E. Low
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - E. Neil Cagle
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Maia Carnevali
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Alexander Lee
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Di Song
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Ada Kung
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - James A. Bradburne
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Xavier Paliard
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
| | - Gerd G. Kochendoerfer
- Contribution from Gryphon Therapeutics, 600 Gateway Boulevard, South San Francisco, California 94080
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183
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Tsiolakidou G, Koutroubakis IE. Stimulating erythropoiesis in inflammatory bowel disease associated anemia. World J Gastroenterol 2007; 13:4798-806. [PMID: 17828809 PMCID: PMC4611757 DOI: 10.3748/wjg.v13.i36.4798] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 07/02/2007] [Accepted: 07/09/2007] [Indexed: 02/06/2023] Open
Abstract
Anemia is a frequent complication in patients with inflammatory bowel disease (IBD), and is associated with decreased quality of life and increased rate of hospitalization. The primary therapeutic targets of IBD-associated anemia are iron deficiency and anemia of chronic disease. An important prognostic parameter of the success or failure of therapy is the outcome of the underlying disease. Iron deficiency should be appropriately managed with iron supplementation. However, the use of oral iron therapy is limited by several problems, the most important being gastrointestinal side effects leading occasionally to disease relapse and poor iron absorption. Intravenous iron preparations are more reliable, with iron sucrose demonstrating the best efficacy and tolerability. Treatment with erythropoietin or darbepoetin has been proven to be effective in patients with anemia, who fail to respond to intravenous iron. Patients with ongoing inflammation have anemia of chronic disease and may require combination therapy comprising of intravenous iron sucrose and erythropoietin. After initiating treatment, careful monitoring of hemoglobin levels and iron parameters is needed in order to avoid recurrence of anemia. In conclusion, anemia in the setting of IBD should be aggressively diagnosed, investigated, and treated. Future studies should define the optimal dose and schedule of intravenous iron supplementation and appropriate erythropoietin therapy in these patients.
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184
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Kostiainen MA, Szilvay GR, Lehtinen J, Smith DK, Linder MB, Urtti A, Ikkala O. Precisely defined protein-polymer conjugates: construction of synthetic DNA binding domains on proteins by using multivalent dendrons. ACS NANO 2007; 1:103-113. [PMID: 19206526 DOI: 10.1021/nn700053y] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Nature has evolved proteins and enzymes to carry out a wide range of sophisticated tasks. Proteins modified with functional polymers possess many desirable physical and chemical properties and have applications in nanobiotechnology. Here we describe multivalent Newkome-type polyamine dendrons that function as synthetic DNA binding domains, which can be conjugated with proteins. These polyamine dendrons employ naturally occurring spermine surface groups to bind DNA with high affinity and are attached onto protein surfaces in a site-specific manner to yield well-defined one-to-one protein-polymer conjugates, where the number of dendrons and their attachment site on the protein surface are precisely known. This precise structure is achieved by using N-maleimido-core dendrons that selectively react via 1,4-conjugate addition with a single free thiol group on the protein surface--either Cys-34 of bovine serum albumin (BSA) or a genetically engineered cysteine mutant of Class II hydrophobin (HFBI). This reaction can be conducted in mild aqueous solutions (pH 7.2-7.4) and at ambient temperature, resulting in BSA- and HFBI-dendron conjugates. The protein-dendron conjugates constitute a specific biosynthetic diblock copolymer and bind DNA with high affinity, as shown by ethidium bromide displacement assay. Importantly, even the low-molecular-weight first-generation polyamine dendron (1 kDa) can bind a large BSA protein (66.4 kDa) to DNA with relatively good affinity. Preliminary gene transfection, cytotoxicity, and self-assembly studies establish the relevance of this methodology for in vitro applications, such as gene therapy and surface patterning. These results encourage further developments in protein-dendron block copolymer-like conjugates and will allow the advance of functional biomimetic nanoscale materials.
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Affiliation(s)
- Mauri A Kostiainen
- Department of Engineering, Physics, and Mathematics and Center for New Materials, Helsinki University of Technology, P.O. Box 2200, 02015 HUT, Espoo, Finland.
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185
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186
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Rajagopal S, Kent SBH. Total chemical synthesis and biophysical characterization of the minimal isoform of the KChIP2 potassium channel regulatory subunit. Protein Sci 2007; 16:2056-64. [PMID: 17660260 PMCID: PMC2206977 DOI: 10.1110/ps.072876107] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The potassium channel accessory subunit KChIP2 associates with Kv4.2 channels in the cardiac myocyte and is involved in the regulation of the transient outward current (I(to)) during the early phase of repolarization of the action potential. As a first step to biophysically probe the mechanism of KChIP2, we have chemically synthesized its minimal isoform, KChIP2d, using Boc chemistry solid phase peptide synthesis in conjunction with native chemical ligation. The synthetic KChIP2d protein is primarily alpha-helical as predicted and becomes more structured upon binding calcium as assessed by (1)H-NMR and CD spectroscopy. Synthetic KChIP2d is in a monomer-dimer equilibrium in solution, and there is evidence for two monomer binding sites on an N-terminal peptide of Kv4.2. Planned future studies include the incorporation of fluorescent and spin labeled probes in KChIP2d to yield structural information in parallel with electrophysiologic studies to elucidate KChIP2d's mechanism of action.
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Affiliation(s)
- Sudarshan Rajagopal
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA.
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187
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Bang D, Pentelute BL, Kent SBH. Kinetically controlled ligation for the convergent chemical synthesis of proteins. Angew Chem Int Ed Engl 2007; 45:3985-8. [PMID: 16639756 DOI: 10.1002/anie.200600702] [Citation(s) in RCA: 249] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Duhee Bang
- Department of Chemistry, Institute for Biophysical Dynamics, Center for Integrative Science, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA.
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188
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Heredia KL, Tolstyka ZP, Maynard HD. Aminooxy End-Functionalized Polymers Synthesized by ATRP for Chemoselective Conjugation to Proteins. Macromolecules 2007. [DOI: 10.1021/ma070432v] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karina L. Heredia
- Department of Chemistry and Biochemistry & California NanoSystems Institute, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569
| | - Zachary P. Tolstyka
- Department of Chemistry and Biochemistry & California NanoSystems Institute, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569
| | - Heather D. Maynard
- Department of Chemistry and Biochemistry & California NanoSystems Institute, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569
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189
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Wu B, Chen J, Warren JD, Chen G, Hua Z, Danishefsky SJ. Building complex glycopeptides: Development of a cysteine-free native chemical ligation protocol. Angew Chem Int Ed Engl 2007; 45:4116-25. [PMID: 16710874 DOI: 10.1002/anie.200600538] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Bin Wu
- The Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY 10021, USA
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190
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Segura J, Pascual JA, Gutiérrez-Gallego R. Procedures for monitoring recombinant erythropoietin and analogues in doping control. Anal Bioanal Chem 2007; 388:1521-9. [PMID: 17516052 DOI: 10.1007/s00216-007-1316-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 04/16/2007] [Accepted: 04/20/2007] [Indexed: 12/28/2022]
Abstract
The present report summarizes the main analytical strategies developed to identify the presence of recombinant erythropoietin (EPO) administered as a doping agent. Indirect evidence is based on the analysis of blood parameters (haemoglobin, haematocrit, reticulocytes, macrocytes, etc.) and serum markers (concentration of EPO and serum transferrin receptors, etc.). The problem of intertechnique comparison for reliable results evaluation is emphasized, especially for serum markers. Charge differences between isoforms of recombinant EPO and native urinary EPO are the grounds for the isoelectric focusing-double blotting-chemiluminescence detection method presently approved for doping control. Works addressing its advantages and limitations are presented and commented on. The chemical bases of the differential detection are highlighted and some future approaches for detection are also presented. The appearance and detectability of EPO analogues and mimetics susceptible for abuse are also addressed.
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Affiliation(s)
- Jordi Segura
- Pharmacology Research Unit, Municipal Institute for Medical Research, IMIM-Hospital del Mar, Dr. Aiguader 88, 08003 Barcelona, Spain.
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191
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Torbeev VY, Kent SBH. Convergent chemical synthesis and crystal structure of a 203 amino acid "covalent dimer" HIV-1 protease enzyme molecule. Angew Chem Int Ed Engl 2007; 46:1667-70. [PMID: 17397076 DOI: 10.1002/anie.200604087] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Vladimir Yu Torbeev
- Department of Chemistry, Institute for Biophysical Dynamics, Gordon Center for Integrative Science, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA
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192
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193
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Durek T, Torbeev VY, Kent SBH. Convergent chemical synthesis and high-resolution x-ray structure of human lysozyme. Proc Natl Acad Sci U S A 2007; 104:4846-51. [PMID: 17360367 PMCID: PMC1829227 DOI: 10.1073/pnas.0610630104] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this article, we report the total chemical synthesis of human lysozyme. Lysozyme serves as a widespread model system in various fields of biochemical research, including protein folding, enzyme catalysis, and amyloidogenesis. The 130-aa wild-type polypeptide chain of the human enzyme was assembled from four polypeptide segments by using native chemical ligation in a fully convergent fashion. Key to the assembly strategy is the application of the recently developed kinetically controlled ligation methodology, which provides efficient control over the ligation of two peptide (alpha)thioesters to yield a unique product. This result enables the facile preparation of a 64-residue peptide (alpha)thioester; this segment is joined by native chemical ligation to a 66-aa Cys peptide, to yield the target 130-aa polypeptide chain. The synthetic polypeptide chain was folded in vitro into a defined tertiary structure with concomitant formation of four disulfides, as shown by 2D TOCSY NMR spectroscopy. The structure of the synthetic human lysozyme was confirmed by high-resolution x-ray diffraction, giving the highest-resolution structure (1.04 A) observed to date for this enzyme. Synthetic lysozyme was obtained in good yield and excellent purity and had full enzymatic activity. This facile and efficient convergent synthesis scheme will enable preparation of unique chemical analogs of the lysozyme molecule and will prove useful in numerous areas of lysozyme research in the future.
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Affiliation(s)
- Thomas Durek
- Institute for Biophysical Dynamics, Department of Biochemistry and Molecular Biology, Department of Chemistry, University of Chicago, 929 East 57th Street, Chicago, IL 60637
| | - Vladimir Yu. Torbeev
- Institute for Biophysical Dynamics, Department of Biochemistry and Molecular Biology, Department of Chemistry, University of Chicago, 929 East 57th Street, Chicago, IL 60637
| | - Stephen B. H. Kent
- Institute for Biophysical Dynamics, Department of Biochemistry and Molecular Biology, Department of Chemistry, University of Chicago, 929 East 57th Street, Chicago, IL 60637
- *To whom correspondence should be addressed. E-mail:
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194
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Torbeev V, Kent S. Convergent Chemical Synthesis and Crystal Structure of a 203 Amino Acid “Covalent Dimer” HIV-1 Protease Enzyme Molecule. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200604087] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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195
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Wu Z, Li X, Ericksen B, de Leeuw E, Zou G, Zeng P, Xie C, Li C, Lubkowski J, Lu WY, Lu W. Impact of pro segments on the folding and function of human neutrophil alpha-defensins. J Mol Biol 2007; 368:537-49. [PMID: 17355880 PMCID: PMC2754399 DOI: 10.1016/j.jmb.2007.02.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 01/26/2007] [Accepted: 02/11/2007] [Indexed: 01/15/2023]
Abstract
Human neutrophil alpha-defensins (HNPs) are synthesized in vivo as inactive precursor proteins, i.e. preproHNPs. A series of sequential proteolytic events excise the N-terminal inhibitory pro peptide, leading to defensin maturation and storage in azurophilic granules. The anionic pro peptide, required for correct sub-cellular trafficking and sorting of proHNPs, inhibits the antimicrobial activity of cationic defensins, either inter or intra-molecularly, presumably through charge neutralization. To better understand the role of the pro peptide in the folding and functioning of alpha-defensins and/or pro alpha-defensins, we chemically attached the proHNP1 pro peptide or (wt)pro peptide and the following artificial pro segments to the N terminus of HNP1: polyethylene glycol (PEG), Arg(10) (polyR), Ser(10) (polyS), and (cr)pro peptide, a charge-reversing mutant of the pro peptide where Arg/Lys residues were changed to Asp, and Asp/Glu residues to Lys. Comparative in vitro folding suggested that while all artificial pro segments chaperoned defensin folding, with PEG being the most efficient, the pro peptide catalyzed the folding of proHNPs likely through two independent mechanisms: solubilization of and interaction with the C-terminal defensin domain. Further, the N-terminal artificial pro segments dramatically altered the bactericidal activity of HNP1 against both Escherichia coli and Staphylococcus aureus. Surprisingly, (cr)pro peptide and (wt)pro peptide showed similar properties with respect to intra-molecular and inter-molecular catalysis of defensin folding as well as alpha-defensin binding, although their binding modes appeared different. Our findings identify a dual chaperone activity of the pro peptide and may shed light on the molecular mechanisms by which pro alpha-defensins fold in vivo.
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Affiliation(s)
- Zhibin Wu
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201
| | - Xiangqun Li
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201
| | - Bryan Ericksen
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201
| | - Erik de Leeuw
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201
| | - Guozhang Zou
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201
| | - Pengyun Zeng
- Fudan-PharmCo Drug Target Research Center, School of Pharmacy, Fudan University, Shanghai 200032, China
| | - Cao Xie
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201
- Fudan-PharmCo Drug Target Research Center, School of Pharmacy, Fudan University, Shanghai 200032, China
| | - Cong Li
- Fudan-PharmCo Drug Target Research Center, School of Pharmacy, Fudan University, Shanghai 200032, China
| | - Jacek Lubkowski
- Macromolecular Assembly Structure and Cell Signaling Section, NCI, National Institutes of Health, Frederick, MD 21702
| | - Wei-Yue Lu
- Fudan-PharmCo Drug Target Research Center, School of Pharmacy, Fudan University, Shanghai 200032, China
| | - Wuyuan Lu
- Institute of Human Virology, University of Maryland Biotechnology Institute, 725 West Lombard Street, Baltimore, MD 21201
- Author to whom correspondence should be addressed: Wuyuan Lu, , Tel: (410)706-4980, Fax: (410)706-7583
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196
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Abstract
In the light of the enthusiasm regarding the use of recombinant human erythropoietin (Epo) and its analogues for treatment of the anaemias of chronic renal failure and malignancies it is worth remembering that today's success has been based on a century of laborious research. The concept of the humoral regulation of haematopoiesis was first formulated in 1906. The term 'erythropoietin' for the erythropoiesis-stimulating hormone was introduced in 1948. Native human Epo was isolated in 1977 and its gene cloned in 1985. During the last 15 yr, major progress has been made in identifying the molecules controlling Epo gene expression, primarily the hypoxia-inducible transcription factors (HIF) that are regulated by specific O2 and oxoglutarate requiring Fe2+-containing dioxygenases. With respect to the action of Epo, its dimeric receptor (Epo-R) has been characterised and shown to signal through protein kinases, anti-apoptotic proteins and transcription factors. The demonstration of Epo-R in non-haematopoietic tissues indicates that Epo is a pleiotropic viability and growth factor. The neuroprotective and cardioprotective potentials of Epo are reviewed with a focus on clinical research. In addition, studies utilising the Epo derivatives with prolonged half-life, peptidic and non-peptidic Epo mimetics, orally active drugs stimulating endogenous Epo production and Epo gene transfer are reviewed.
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197
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Abstract
Red cell production in chronic kidney disease is usually too low to maintain a normal haemoglobin, and thus anaemia develops in a large proportion of patients. The ability to stimulate erythropoiesis in the bone marrow by the use of therapeutic agents has only been possible in the last 20 years, initially with recombinant human erythropoietin (epoetin), and later darbepoetin alfa. Many new agents are, however, in clinical development, and these include CERA, Hematide, and HIF stabilisers, in addition to the imminent launch of biosimilar epoetins. The main issue with biosimilars is the unknown risk of immunogenicity. CERA is a large molecule, approximately twice the size of epoetin, which was created by integrating a single polymer chain into the erythropoietin molecule. CERA has a much prolonged half-life, and Phase II and III clinical trials have investigated administration of CERA every 3 or 4 weeks. Hematide is derived from original research on the erythropoietin-mimetic peptides, and is in Phase II of its clinical trial programme. Again, this compound is being investigated as a once-monthly administration. The HIF stabilizers are orally-active inhibitors of the enzyme that degrades hypoxia-inducible factor (prolyl hydroxylase), and this leads to upregulation of erythropoietin gene expression. Other strategies for stimulating erythropoiesis, briefly described in this review, are at an earlier stage of development. This is an exciting and rapidly developing area of scientific and translational research.
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198
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Abstract
Protein-polymer conjugates are widely employed for applications in medicine, biotechnology and nanotechnology. Covalent attachment of synthetic polymers to proteins improves protein stability, solubility, and biocompatibility. Furthermore, synthetic polymers impart new properties such as self assembly and phase behavior. Polymer attachment at amino acid side-chains and at ligand binding sites is typically exploited. This Emerging Area focuses on synthetic methods to prepare protein-reactive polymers and also employing the protein itself as an initiator for polymerization.
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Affiliation(s)
- Karina L Heredia
- Department of Chemistry and Biochemistry and the California NanoSystems Institute, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, CA 90095-1569, USA
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199
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Transfer allyl esters to thioesters in solid phase condition: synthesis of peptide thioesters by Fmoc chemistry. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2006.11.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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200
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Vadas O, Rose K. Multivalency—a way to enhance binding avidities and bioactivity—preliminary applications to EPO. J Pept Sci 2007; 13:581-7. [PMID: 17631671 DOI: 10.1002/psc.794] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Multivalency has advantages over monovalency for binding interactions and even for activity. In particular, avidity is higher since the off-rate of a multivalent species is much slower than that of a monomer. This is particularly profitable for ligand-binding receptors that require dimerization for activity, such as the receptor of erythropoietin (EPOR). Peptides that mimic the action of erythropoietin (EPO) have been described with no sequence similarity with the human hormone: erythropoietin mimetic peptide (EMP) and EPO receptor peptide (ERP). These two peptides have similar activity but interact through different sites on the EPOR. Here, we describe the construction of several new synthetic homo- and hetero-dimers based on EMP-ERP sequences. To link the monomeric molecules together, several monodisperse polyamide linkers of different lengths were synthesized with dialdehyde functionalities. Chemoselective oxime chemistry was used to obtain homogeneous constructs. Certain chemical incompatibilities were dealt with via a protection approach. The oximes are stable under normal conditions and so lend themselves to biological testing.
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Affiliation(s)
- Oscar Vadas
- Department of Structural Biology and Bioinformatics, University Medical Center (CMU), University of Geneva, CH-1211 Geneva 4, Switzerland.
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