1
|
Soxpollard N, Strauss S, Jungmann R, MacPherson IS. Selection of antibody-binding covalent aptamers. Commun Chem 2024; 7:174. [PMID: 39117896 PMCID: PMC11310417 DOI: 10.1038/s42004-024-01255-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 07/24/2024] [Indexed: 08/10/2024] Open
Abstract
Aptamers are oligonucleotides with antibody-like binding function, selected from large combinatorial libraries. In this study, we modified a DNA aptamer library with N-hydroxysuccinimide esters, enabling covalent conjugation with cognate proteins. We selected for the ability to bind to mouse monoclonal antibodies, resulting in the isolation of two distinct covalent binding motifs. The covalent aptamers are specific for the Fc region of mouse monoclonal IgG1 and are cross-reactive with mouse IgG2a and other IgGs. Investigation into the covalent conjugation of the aptamers revealed a dependence on micromolar concentrations of Cu2+ ions which can be explained by residual catalyst remaining after modification of the aptamer library. The aptamers were successfully used as adapters in the formation of antibody-oligonucleotide conjugates (AOCs) for use in detection of HIV protein p24 and super-resolution imaging of actin. This work introduces a new method for the site-specific modification of native monoclonal antibodies and may be useful in applications requiring AOCs or other antibody conjugates.
Collapse
Affiliation(s)
- Noah Soxpollard
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, University of Hawaii, Honolulu, HI, 96813, USA
| | - Sebastian Strauss
- Max Planck Institute of Biochemistry, Planegg, Germany
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany
| | - Ralf Jungmann
- Max Planck Institute of Biochemistry, Planegg, Germany
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany
| | - Iain S MacPherson
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, University of Hawaii, Honolulu, HI, 96813, USA.
| |
Collapse
|
2
|
DeRosa M, Lin A, Mallikaratchy P, McConnell E, McKeague M, Patel R, Shigdar S. In vitro selection of aptamers and their applications. NATURE REVIEWS. METHODS PRIMERS 2023; 3:55. [PMID: 37969927 PMCID: PMC10647184 DOI: 10.1038/s43586-023-00247-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
The introduction of the in-vitro evolution method known as SELEX (Systematic Evolution of Ligands by Exponential enrichment) more than 30 years ago led to the conception of versatile synthetic receptors known as aptamers. Offering many benefits such as low cost, high stability and flexibility, aptamers have sparked innovation in molecular diagnostics, enabled advances in synthetic biology and have facilitated new therapeutic approaches. The SELEX method itself is inherently adaptable and offers near limitless possibilities in yielding functional nucleic acid ligands. This Primer serves to provide guidance on experimental design and highlight new growth areas for this impactful technology.
Collapse
Affiliation(s)
- M.C. DeRosa
- Department of Chemistry and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1T2S2
| | - A. Lin
- Department of Chemistry, Faculty of Sciences, McGill University, Montreal, QC, Canada, H3A 0B8
| | - P. Mallikaratchy
- Department of Molecular, Cellular, and Biomedical Sciences, City University of New York School of Medicine, New York, NY 10031, USA
- Ph.D. Programs in Chemistry and Biochemistry, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA
- Ph.D. Program in Molecular, Cellular and Developmental Biology, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA
| | - E.M. McConnell
- Department of Chemistry and Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1T2S2
| | - M. McKeague
- Department of Chemistry, Faculty of Sciences, McGill University, Montreal, QC, Canada, H3A 0B8
- Department of Pharmacology and Therapeutics, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada, H3G 1Y6
| | - R. Patel
- Ph.D. Programs in Chemistry and Biochemistry, CUNY Graduate Center, 365 Fifth Avenue, New York, NY 10016, USA
| | - S. Shigdar
- School of Medicine, Deakin University, Geelong, VIC 3220, Australia
- Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Deakin University, Geelong, VIC 3220, Australia
| |
Collapse
|
3
|
Neralkar M, Xu B, Horiya S, Krauss IJ. Large-Scale Synthesis of Man 9GlcNAc 2 High-Mannose Glycan and the Effect of the Glycan Core on Multivalent Recognition by HIV Antibody 2G12. ACS Infect Dis 2022; 8:2232-2241. [PMID: 36278940 DOI: 10.1021/acsinfecdis.2c00442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Access to homogeneous high-mannose glycans in high-mg quantities is necessary for carbohydrate-based HIV vaccine development research. We have used directed evolution to design highly antigenic oligomannose clusters that are recognized in low-nM affinity by HIV antibodies. Herein we report an optimized large-scale synthesis of Man9GlcNAc2 including improved building block synthesis and a fully stereoselective 5 + 6 coupling, yielding 290 mg of glycan. We then use this glycan to study the effect of the GlcNAc2 core on the antigenicity of an evolved 2G12-binding glycopeptide, 10F2.
Collapse
Affiliation(s)
- Mahesh Neralkar
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, United States
| | - Bokai Xu
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, United States
| | - Satoru Horiya
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, United States
| | - Isaac J Krauss
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454, United States
| |
Collapse
|
4
|
Wu KB, Skrodzki CJA, Su Q, Lin J, Niu J. "Click handle"-modified 2'-deoxy-2'-fluoroarabino nucleic acid as a synthetic genetic polymer capable of post-polymerization functionalization. Chem Sci 2022; 13:6873-6881. [PMID: 35774169 PMCID: PMC9200136 DOI: 10.1039/d2sc00679k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/16/2022] [Indexed: 01/01/2023] Open
Abstract
The functions of natural nucleic acids such as DNA and RNA have transcended genetic information carriers and now encompass affinity reagents, molecular catalysts, nanostructures, data storage, and many others. However, the vulnerability of natural nucleic acids to nuclease degradation and the lack of chemical functionality have imposed a significant constraint on their ever-expanding applications. Herein, we report the synthesis and polymerase recognition of a 5-(octa-1,7-diynyl)uracil 2′-deoxy-2′-fluoroarabinonucleic acid (FANA) triphosphate. The DNA-templated, polymerase-mediated primer extension using this “click handle”-modified FANA (cmFANA) triphosphate and other FANA nucleotide triphosphates consisting of canonical nucleobases efficiently generated full-length products. The resulting cmFANA polymers exhibited excellent nuclease resistance and the ability to undergo efficient click conjugation with azide-functionalized molecules, thereby becoming a promising platform for serving as a programmable and evolvable synthetic genetic polymer capable of post-polymerization functionalization. Polymerase-mediated incorporation of a “click handle”-modified fluoroarabinonucleic acid (cmFANA) triphosphate produces a new class of nuclease-resistant, evolvable genetic polymers that can be functionalized with azide-containing molecules.![]()
Collapse
Affiliation(s)
- Kevin B Wu
- Department of Chemistry, Boston College 2609 Beacon Street, Chestnut Hill MA 20467 USA
| | | | - Qiwen Su
- Department of Chemistry, Boston College 2609 Beacon Street, Chestnut Hill MA 20467 USA
| | - Jennifer Lin
- Department of Chemistry, Boston College 2609 Beacon Street, Chestnut Hill MA 20467 USA
| | - Jia Niu
- Department of Chemistry, Boston College 2609 Beacon Street, Chestnut Hill MA 20467 USA
| |
Collapse
|
5
|
Redman RL, Krauss IJ. Directed Evolution of 2'-Fluoro-Modified, RNA-Supported Carbohydrate Clusters That Bind Tightly to HIV Antibody 2G12. J Am Chem Soc 2021; 143:8565-8571. [PMID: 34096703 DOI: 10.1021/jacs.1c03194] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Carbohydrate binding proteins (CBPs) are attractive targets in medicine and biology. Multivalency, with several glycans binding to several binding pockets in the CBP, is important for high-affinity interactions. Herein, we describe a novel platform for design of multivalent carbohydrate cluster ligands by directed evolution, in which serum-stable 2'-fluoro modified RNA (F-RNA) backbones evolve to present the glycan in optimal clusters. We have validated this method by the selection of oligomannose (Man9) glycan clusters from a sequence pool of ∼1013 that bind to broadly neutralizing HIV antibody 2G12 with 13 to 36 nM affinities.
Collapse
Affiliation(s)
- Richard L Redman
- Department of Chemistry, Brandeis University, 415 South Street MS 015, Waltham, Massachusetts 02454, United States
| | - Isaac J Krauss
- Department of Chemistry, Brandeis University, 415 South Street MS 015, Waltham, Massachusetts 02454, United States
| |
Collapse
|
6
|
Ochoa S, Milam VT. Modified Nucleic Acids: Expanding the Capabilities of Functional Oligonucleotides. Molecules 2020; 25:E4659. [PMID: 33066073 PMCID: PMC7587394 DOI: 10.3390/molecules25204659] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/20/2022] Open
Abstract
In the last three decades, oligonucleotides have been extensively investigated as probes, molecular ligands and even catalysts within therapeutic and diagnostic applications. The narrow chemical repertoire of natural nucleic acids, however, imposes restrictions on the functional scope of oligonucleotides. Initial efforts to overcome this deficiency in chemical diversity included conservative modifications to the sugar-phosphate backbone or the pendant base groups and resulted in enhanced in vivo performance. More importantly, later work involving other modifications led to the realization of new functional characteristics beyond initial intended therapeutic and diagnostic prospects. These results have inspired the exploration of increasingly exotic chemistries highly divergent from the canonical nucleic acid chemical structure that possess unnatural physiochemical properties. In this review, the authors highlight recent developments in modified oligonucleotides and the thrust towards designing novel nucleic acid-based ligands and catalysts with specifically engineered functions inaccessible to natural oligonucleotides.
Collapse
Affiliation(s)
- Steven Ochoa
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Valeria T. Milam
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
| |
Collapse
|
7
|
Nguyen DN, Redman RL, Horiya S, Bailey JK, Xu B, Stanfield RL, Temme JS, LaBranche CC, Wang S, Rodal AA, Montefiori DC, Wilson IA, Krauss IJ. The Impact of Sustained Immunization Regimens on the Antibody Response to Oligomannose Glycans. ACS Chem Biol 2020; 15:789-798. [PMID: 32109354 PMCID: PMC7091532 DOI: 10.1021/acschembio.0c00053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
The high mannose
patch (HMP) of the HIV envelope protein (Env)
is the structure most frequently targeted by broadly neutralizing
antibodies; therefore, many researchers have attempted to use mimics
of this region as a vaccine immunogen. In our previous efforts, vaccinating
rabbits with evolved HMP mimic glycopeptides containing Man9 resulted in an overall antibody response targeting the glycan core
and linker rather than the full glycan or Manα1→2Man
tips of Man9 glycans. A possible reason could be processing
of our immunogen by host serum mannosidases. We sought to test whether
more prolonged dosing could increase the antibody response to intact
glycans, possibly by increasing the availability of intact Man9 to germinal centers. Here, we describe a study investigating
the impact of immunization regimen on antibody response by testing
immunogen delivery through bolus, an exponential series of mini doses,
or a continuously infusing mini-osmotic pump. Our results indicate
that, with our glycopeptide immunogens, standard bolus immunization
elicited the strongest HIV Env-binding antibody response, even though
higher overall titers to the glycopeptide were elicited by the exponential
and pump regimens. Antibody selectivity for intact glycan was, if
anything, slightly better in the bolus-immunized animals.
Collapse
Affiliation(s)
- Dung N. Nguyen
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Richard L. Redman
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Satoru Horiya
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Jennifer K. Bailey
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Bokai Xu
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Robyn L. Stanfield
- Department of Integrative Structural and Computational Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - J. Sebastian Temme
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Celia C. LaBranche
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Shiyu Wang
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Avital A. Rodal
- Department of Biology, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - David C. Montefiori
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Isaac J. Krauss
- Department of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| |
Collapse
|
8
|
Nguyen DN, Xu B, Stanfield RL, Bailey JK, Horiya S, Temme JS, Leon DR, LaBranche CC, Montefiori DC, Costello CE, Wilson IA, Krauss IJ. Oligomannose Glycopeptide Conjugates Elicit Antibodies Targeting the Glycan Core Rather than Its Extremities. ACS CENTRAL SCIENCE 2019; 5:237-249. [PMID: 30834312 PMCID: PMC6396197 DOI: 10.1021/acscentsci.8b00588] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Indexed: 06/01/2023]
Abstract
Up to ∼20% of HIV-infected individuals eventually develop broadly neutralizing antibodies (bnAbs), and many of these antibodies (∼40%) target a region of dense high-mannose glycosylation on gp120 of the HIV envelope protein, known as the "high-mannose patch" (HMP). Thus, there have been numerous attempts to develop glycoconjugate vaccine immunogens that structurally mimic the HMP and might elicit bnAbs targeting this conserved neutralization epitope. Herein, we report on the immunogenicity of glycopeptides, designed by in vitro selection, that bind tightly to anti-HMP antibody 2G12. By analyzing the fine carbohydrate specificity of rabbit antibodies elicited by these immunogens, we found that they differ from some natural human bnAbs, such as 2G12 and PGT128, in that they bind primarily to the core structures within the glycan, rather than to the Manα1 → 2Man termini (2G12) or to the whole glycan (PGT128). Antibody specificity for the glycan core may result from extensive serum mannosidase trimming of the immunogen in the vaccinated animals. This finding has broad implications for vaccine design aiming to target glycan-dependent HIV neutralizing antibodies.
Collapse
Affiliation(s)
- Dung N. Nguyen
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Bokai Xu
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Robyn L. Stanfield
- Department
of Integrative Structural and Computational Biology and the Skaggs
Institute for Chemical Biology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Jennifer K. Bailey
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Satoru Horiya
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - J. Sebastian Temme
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| | - Deborah R. Leon
- Department
of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts 02215, United States
| | - Celia C. LaBranche
- Department
of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - David C. Montefiori
- Department
of Surgery, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Catherine E. Costello
- Department
of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, Massachusetts 02215, United States
| | - Ian A. Wilson
- Department
of Integrative Structural and Computational Biology and the Skaggs
Institute for Chemical Biology, The Scripps
Research Institute, La Jolla, California 92037, United States
| | - Isaac J. Krauss
- Department
of Chemistry, Brandeis University, Waltham, Massachusetts 02454-9110, United States
| |
Collapse
|
9
|
MacPherson IS, Temme JS, Krauss IJ. DNA display of folded RNA libraries enabling RNA-SELEX without reverse transcription. Chem Commun (Camb) 2018; 53:2878-2881. [PMID: 28220154 DOI: 10.1039/c6cc09991b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A method for the physical attachment of folded RNA libraries to their encoding DNA is presented as a way to circumvent the reverse transcription step during systematic evolution of RNA ligands by exponential enrichment (RNA-SELEX). A DNA library is modified with one isodC base to stall T7 polymerase and a 5' "capture strand" which anneals to the nascent RNA transcript. This method is validated in a selection of RNA aptamers against human α-thrombin with dissociation constants in the low nanomolar range. This method will be useful in the discovery of RNA aptamers and ribozymes containing base modifications that make them resistant to accurate reverse transcription.
Collapse
Affiliation(s)
- I S MacPherson
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawai'i at Manoa, 651 Ilalo St., Biosciences Building, Suite 325, Honolulu, Hawaii 96813-5525, USA. and Department of Chemistry, Brandeis University, 415 South St. MS 015, Waltham, MA 02454-9110, USA.
| | - J S Temme
- Department of Chemistry, Brandeis University, 415 South St. MS 015, Waltham, MA 02454-9110, USA.
| | - I J Krauss
- Department of Chemistry, Brandeis University, 415 South St. MS 015, Waltham, MA 02454-9110, USA.
| |
Collapse
|
10
|
Vorobyeva MA, Davydova AS, Vorobjev PE, Pyshnyi DV, Venyaminova AG. Key Aspects of Nucleic Acid Library Design for in Vitro Selection. Int J Mol Sci 2018; 19:E470. [PMID: 29401748 PMCID: PMC5855692 DOI: 10.3390/ijms19020470] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/31/2018] [Accepted: 02/02/2018] [Indexed: 02/07/2023] Open
Abstract
Nucleic acid aptamers capable of selectively recognizing their target molecules have nowadays been established as powerful and tunable tools for biospecific applications, be it therapeutics, drug delivery systems or biosensors. It is now generally acknowledged that in vitro selection enables one to generate aptamers to almost any target of interest. However, the success of selection and the affinity of the resulting aptamers depend to a large extent on the nature and design of an initial random nucleic acid library. In this review, we summarize and discuss the most important features of the design of nucleic acid libraries for in vitro selection such as the nature of the library (DNA, RNA or modified nucleotides), the length of a randomized region and the presence of fixed sequences. We also compare and contrast different randomization strategies and consider computer methods of library design and some other aspects.
Collapse
Affiliation(s)
- Maria A. Vorobyeva
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences, Lavrentiev Ave., 8, 630090 Novosibirsk, Russia; (A.S.D.); (P.E.V.); (D.V.P.); (A.G.V.)
| | - Anna S. Davydova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences, Lavrentiev Ave., 8, 630090 Novosibirsk, Russia; (A.S.D.); (P.E.V.); (D.V.P.); (A.G.V.)
| | - Pavel E. Vorobjev
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences, Lavrentiev Ave., 8, 630090 Novosibirsk, Russia; (A.S.D.); (P.E.V.); (D.V.P.); (A.G.V.)
- Department of Natural Sciences, Novosibirsk State University, Pirogova St., 2, 630090 Novosibirsk, Russia
| | - Dmitrii V. Pyshnyi
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences, Lavrentiev Ave., 8, 630090 Novosibirsk, Russia; (A.S.D.); (P.E.V.); (D.V.P.); (A.G.V.)
- Department of Natural Sciences, Novosibirsk State University, Pirogova St., 2, 630090 Novosibirsk, Russia
| | - Alya G. Venyaminova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Division of Russian Academy of Sciences, Lavrentiev Ave., 8, 630090 Novosibirsk, Russia; (A.S.D.); (P.E.V.); (D.V.P.); (A.G.V.)
| |
Collapse
|
11
|
Abstract
Directed evolution is a useful method for the discovery of nucleic acids, peptides, or proteins that have desired binding abilities or functions. Because of the abundance and importance of glycosylation in nature, directed evolution of glycopeptides and glycoproteins is also highly desirable. However, common directed evolution platforms such as phage-, yeast-, or mammalian-cell display are limited for these applications by several factors. Glycan structure at each glycosylation site is not genetically encoded, and yeast and mammalian cells produce a heterogeneous mixture of glycoforms at each site on the protein. Although yeast, mammalian and Escherichia coli cells can be engineered to produce a homogenous glycoform at all glycosylation sites, there are just a few specific glycan structures that can readily be accessed in this manner. Recently, we reported a novel system for the directed evolution of glycopeptide libraries, which could in principle be decorated with any desired glycan. Our method combines in vitro peptide selection by mRNA display with unnatural amino acid incorporation and chemical attachment of synthetic oligosaccharides. Here, we provide an updated and optimized protocol for this method, which is designed to create glycopeptide mRNA display libraries containing ~1013 sequences and select them for target binding. The target described here is the HIV broadly neutralizing monoclonal antibody 2G12; 2G12 binds to cluster of high-mannose oligosaccharides on the HIV envelope glycoprotein gp120; and glycopeptides that mimic this epitope may be useful in HIV vaccine applications. This method is expected to be readily applicable for other types of glycans and targets of interest in glycobiology.
Collapse
|
12
|
Evolution of Complex Target SELEX to Identify Aptamers against Mammalian Cell-Surface Antigens. Molecules 2017; 22:molecules22020215. [PMID: 28146093 PMCID: PMC5572134 DOI: 10.3390/molecules22020215] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 01/24/2017] [Indexed: 01/10/2023] Open
Abstract
The demand has increased for sophisticated molecular tools with improved detection limits. Such molecules should be simple in structure, yet stable enough for clinical applications. Nucleic acid aptamers (NAAs) represent a class of molecules able to meet this demand. In particular, aptamers, a class of small nucleic acid ligands that are composed of single-stranded modified/unmodified RNA/DNA molecules, can be evolved from a complex library using Systematic Evolution of Ligands by EXponential enrichment (SELEX) against almost any molecule. Since its introduction in 1990, in stages, SELEX technology has itself undergone several modifications, improving selection and broadening the repertoire of targets. This review summarizes these milestones that have pushed the field forward, allowing researchers to generate aptamers that can potentially be applied as therapeutic and diagnostic agents.
Collapse
|
13
|
Alexandre KB, Mufhandu HT, London GM, Chakauya E, Khati M. Progress and Perspectives on HIV-1 microbicide development. Virology 2016; 497:69-80. [PMID: 27429040 DOI: 10.1016/j.virol.2016.07.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 07/01/2016] [Accepted: 07/04/2016] [Indexed: 12/12/2022]
Abstract
The majority of HIV-1 infections occur via sexual intercourse. Women are the most affected by the epidemic, particularly in developing countries, due to their socio-economic dependence on men and the fact that they are often victims of gender based sexual violence. Despite significant efforts that resulted in the reduction of infection rates in some countries, there is still need for effective prevention methods against the virus. One of these methods for preventing sexual transmission in women is the use of microbicides. In this review we provide a summary of the progress made toward the discovery of affordable and effective HIV-1 microbicides and suggest future directions. We show that there is a wide range of compounds that have been proposed as potential microbicides. Although most of them have so far failed to show protection in humans, there are many promising ones currently in pre-clinical studies and in clinical trials.
Collapse
Affiliation(s)
- Kabamba B Alexandre
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa.
| | - Hazel T Mufhandu
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa
| | - Grace M London
- Department of Health Free State District Health Services and Health Programs, South Africa
| | - E Chakauya
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa
| | - M Khati
- Council for Scientific and Industrial Research, Pioneering Health Sciences Laboratory, Biosciences Unit, Pretoria, Gauteng, South Africa; University of Cape Town and Groote Schuur Hospital, Department of Medicine, Cape Town, South Africa
| |
Collapse
|
14
|
Kong D, Yeung W, Hili R. Generation of Synthetic Copolymer Libraries by Combinatorial Assembly on Nucleic Acid Templates. ACS COMBINATORIAL SCIENCE 2016; 18:355-70. [PMID: 27275512 DOI: 10.1021/acscombsci.6b00059] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Recent advances in nucleic acid-templated copolymerization have expanded the scope of sequence-controlled synthetic copolymers beyond the molecular architectures witnessed in nature. This has enabled the power of molecular evolution to be applied to synthetic copolymer libraries to evolve molecular function ranging from molecular recognition to catalysis. This Review seeks to summarize different approaches available to generate sequence-defined monodispersed synthetic copolymer libraries using nucleic acid-templated polymerization. Key concepts and principles governing nucleic acid-templated polymerization, as well as the fidelity of various copolymerization technologies, will be described. The Review will focus on methods that enable the combinatorial generation of copolymer libraries and their molecular evolution for desired function.
Collapse
Affiliation(s)
- Dehui Kong
- Department of Chemistry, University of Georgia, 140 Cedar
Street, Athens, Georgia 30602, United States
| | - Wayland Yeung
- Department of Chemistry, University of Georgia, 140 Cedar
Street, Athens, Georgia 30602, United States
| | - Ryan Hili
- Department of Chemistry, University of Georgia, 140 Cedar
Street, Athens, Georgia 30602, United States
| |
Collapse
|
15
|
Zhou C, Avins JL, Klauser PC, Brandsen BM, Lee Y, Silverman SK. DNA-Catalyzed Amide Hydrolysis. J Am Chem Soc 2016; 138:2106-9. [PMID: 26854515 DOI: 10.1021/jacs.5b12647] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
DNA catalysts (deoxyribozymes) for a variety of reactions have been identified by in vitro selection. However, for certain reactions this identification has not been achieved. One important example is DNA-catalyzed amide hydrolysis, for which a previous selection experiment instead led to DNA-catalyzed DNA phosphodiester hydrolysis. Subsequent efforts in which the selection strategy deliberately avoided phosphodiester hydrolysis led to DNA-catalyzed ester and aromatic amide hydrolysis, but aliphatic amide hydrolysis has been elusive. In the present study, we show that including modified nucleotides that bear protein-like functional groups (any one of primary amino, carboxyl, or primary hydroxyl) enables identification of amide-hydrolyzing deoxyribozymes. In one case, the same deoxyribozyme sequence without the modifications still retains substantial catalytic activity. Overall, these findings establish the utility of introducing protein-like functional groups into deoxyribozymes for identifying new catalytic function. The results also suggest the longer-term feasibility of deoxyribozymes as artificial proteases.
Collapse
Affiliation(s)
- Cong Zhou
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Joshua L Avins
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Paul C Klauser
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Benjamin M Brandsen
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Yujeong Lee
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Scott K Silverman
- Department of Chemistry, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| |
Collapse
|
16
|
Use of aptamers in immunoassays. Mol Immunol 2016; 70:149-54. [PMID: 26774749 DOI: 10.1016/j.molimm.2015.12.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/02/2015] [Accepted: 12/15/2015] [Indexed: 12/19/2022]
Abstract
Aptamers, short single-chain DNA or RNA oligonucleotides, react specifically with small molecules, as well as with proteins. Unlike antibodies, they may be obtained relatively easily. Aptamers are now widely employed in immunological studies and could replace antibodies in immunoassays. In this short review, methods for immobilizing aptamers on various insoluble materials (so-called apta-sorbents) are described. Recent findings on their use in the detection and isolation of immunoglobulins and their application in various immunoassays are also discussed.
Collapse
|