1
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Jeon J, Yau WM, Tycko R. Early events in amyloid-β self-assembly probed by time-resolved solid state NMR and light scattering. Nat Commun 2023; 14:2964. [PMID: 37221174 DOI: 10.1038/s41467-023-38494-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/04/2023] [Indexed: 05/25/2023] Open
Abstract
Self-assembly of amyloid-β peptides leads to oligomers, protofibrils, and fibrils that are likely instigators of neurodegeneration in Alzheimer's disease. We report results of time-resolved solid state nuclear magnetic resonance (ssNMR) and light scattering experiments on 40-residue amyloid-β (Aβ40) that provide structural information for oligomers that form on time scales from 0.7 ms to 1.0 h after initiation of self-assembly by a rapid pH drop. Low-temperature ssNMR spectra of freeze-trapped intermediates indicate that β-strand conformations within and contacts between the two main hydrophobic segments of Aβ40 develop within 1 ms, while light scattering data imply a primarily monomeric state up to 5 ms. Intermolecular contacts involving residues 18 and 33 develop within 0.5 s, at which time Aβ40 is approximately octameric. These contacts argue against β-sheet organizations resembling those found previously in protofibrils and fibrils. Only minor changes in the Aβ40 conformational distribution are detected as larger assemblies develop.
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Affiliation(s)
- Jaekyun Jeon
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0520, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland/National Institute of Standards and Technology, Rockville, MD, 20850, USA
| | - Wai-Ming Yau
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0520, USA
| | - Robert Tycko
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0520, USA.
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2
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Bhagawati M, Hoffmann S, Höffgen KS, Piehler J, Busch KB, Mootz HD. In Cellulo Protein Semi‐Synthesis from Endogenous and Exogenous Fragments Using the Ultra‐Fast Split Gp41‐1 Intein. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Maniraj Bhagawati
- Department of Chemistry and Pharmacy Institute of Biochemistry, University of Münster Corrensstrasse 36 48149 Münster Germany
| | - Simon Hoffmann
- Department of Chemistry and Pharmacy Institute of Biochemistry, University of Münster Corrensstrasse 36 48149 Münster Germany
| | - Katharina S. Höffgen
- Department of Chemistry and Pharmacy Institute of Biochemistry, University of Münster Corrensstrasse 36 48149 Münster Germany
| | - Jacob Piehler
- Department of Biology and Center for Cellular Nanoanalytics University of Osnabrück Barbarastrasse 11 49076 Osnabrück Germany
| | - Karin B. Busch
- Institute of Molecular Cell Biology University of Münster Schlossplatz 5 48149 Münster Germany
| | - Henning D. Mootz
- Department of Chemistry and Pharmacy Institute of Biochemistry, University of Münster Corrensstrasse 36 48149 Münster Germany
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3
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Bhagawati M, Hoffmann S, Höffgen KS, Piehler J, Busch KB, Mootz HD. In Cellulo Protein Semi-Synthesis from Endogenous and Exogenous Fragments Using the Ultra-Fast Split Gp41-1 Intein. Angew Chem Int Ed Engl 2020; 59:21007-21015. [PMID: 32777124 PMCID: PMC7693240 DOI: 10.1002/anie.202006822] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/15/2020] [Indexed: 12/19/2022]
Abstract
Protein semi-synthesis inside live cells from exogenous and endogenous parts offers unique possibilities for studying proteins in their native context. Split-intein-mediated protein trans-splicing is predestined for such endeavors and has seen some successes, but a much larger variety of established split inteins and associated protocols is urgently needed. We characterized the association and splicing parameters of the Gp41-1 split intein, which favorably revealed a nanomolar affinity between the intein fragments combined with the exceptionally fast splicing rate. Following bead-loading of a chemically modified intein fragment precursor into live mammalian cells, we fluorescently labeled target proteins on their N- and C-termini with short peptide tags, thus ensuring minimal perturbation of their structure and function. In combination with a nuclear-entrapment strategy to minimize cytosolic fluorescence background, we applied our technique for super-resolution imaging and single-particle tracking of the outer mitochondrial protein Tom20 in HeLa cells.
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Affiliation(s)
- Maniraj Bhagawati
- Department of Chemistry and PharmacyInstitute of Biochemistry, University of MünsterCorrensstrasse 3648149MünsterGermany
| | - Simon Hoffmann
- Department of Chemistry and PharmacyInstitute of Biochemistry, University of MünsterCorrensstrasse 3648149MünsterGermany
| | - Katharina S. Höffgen
- Department of Chemistry and PharmacyInstitute of Biochemistry, University of MünsterCorrensstrasse 3648149MünsterGermany
| | - Jacob Piehler
- Department of Biology and Center for Cellular NanoanalyticsUniversity of OsnabrückBarbarastrasse 1149076OsnabrückGermany
| | - Karin B. Busch
- Institute of Molecular Cell BiologyUniversity of MünsterSchlossplatz 548149MünsterGermany
| | - Henning D. Mootz
- Department of Chemistry and PharmacyInstitute of Biochemistry, University of MünsterCorrensstrasse 3648149MünsterGermany
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4
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Khoo KK, Galleano I, Gasparri F, Wieneke R, Harms H, Poulsen MH, Chua HC, Wulf M, Tampé R, Pless SA. Chemical modification of proteins by insertion of synthetic peptides using tandem protein trans-splicing. Nat Commun 2020; 11:2284. [PMID: 32385250 PMCID: PMC7210297 DOI: 10.1038/s41467-020-16208-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/20/2020] [Indexed: 12/20/2022] Open
Abstract
Manipulation of proteins by chemical modification is a powerful way to decipher their function. However, most ribosome-dependent and semi-synthetic methods have limitations in the number and type of modifications that can be introduced, especially in live cells. Here, we present an approach to incorporate single or multiple post-translational modifications or non-canonical amino acids into proteins expressed in eukaryotic cells. We insert synthetic peptides into GFP, NaV1.5 and P2X2 receptors via tandem protein trans-splicing using two orthogonal split intein pairs and validate our approach by investigating protein function. We anticipate the approach will overcome some drawbacks of existing protein enigineering methods.
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Affiliation(s)
- K K Khoo
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - I Galleano
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - F Gasparri
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - R Wieneke
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Strasse 9, 60438, Frankfurt/Main, Germany
| | - H Harms
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - M H Poulsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - H C Chua
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - M Wulf
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - R Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Strasse 9, 60438, Frankfurt/Main, Germany
| | - S A Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark.
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5
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Li G, Ma F, Cao Q, Zheng Z, DeLaney K, Liu R, Li L. Nanosecond photochemically promoted click chemistry for enhanced neuropeptide visualization and rapid protein labeling. Nat Commun 2019; 10:4697. [PMID: 31619683 PMCID: PMC6795811 DOI: 10.1038/s41467-019-12548-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 09/17/2019] [Indexed: 12/28/2022] Open
Abstract
Comprehensive protein identification and concomitant structural probing of proteins are of great biological significance. However, this is challenging to accomplish simultaneously in one confined space. Here, we develop a nanosecond photochemical reaction (nsPCR)-based click chemistry, capable of structural probing of proteins and enhancing their identifications through on-demand removal of surrounding matrices within nanoseconds. The nsPCR is initiated using a photoactive compound, 2-nitrobenzaldehyde (NBA), and is examined by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). Benefiting from the on-demand matrix-removal effect, this nsPCR strategy enables enhanced neuropeptide identification and visualization from complex tissue samples such as mouse brain tissue. The design shows great promise for structural probing of proteins up to 155 kDa due to the exclusive accessibility of nsPCR to primary amine groups, as demonstrated by its general applicability using a series of proteins with various lysine residues from multiple sample sources, with accumulated labeling efficiencies greater than 90%. Mass spectrometry-based quantitative proteomics aim to identify and quantify proteins from complex biological samples. Here, the authors developed a method for simultaneous high-throughput protein labelling and on-demand matrix removal within nanoseconds.
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Affiliation(s)
- Gongyu Li
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Fengfei Ma
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Qinjingwen Cao
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Zhen Zheng
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Kellen DeLaney
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Rui Liu
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, 53705, USA. .,Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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6
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A mesophilic cysteine-less split intein for protein trans-splicing applications under oxidizing conditions. Proc Natl Acad Sci U S A 2019; 116:22164-22172. [PMID: 31611397 DOI: 10.1073/pnas.1909825116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Split intein-mediated protein trans-splicing has found extensive applications in chemical biology, protein chemistry, and biotechnology. However, an enduring limitation of all well-established split inteins has been the requirement to carry out the reaction in a reducing environment due to the presence of 1 or 2 catalytic cysteines that need to be in a reduced state for splicing to occur. The concomitant exposure of the fused proteins to reducing agents severely limits the scope of protein trans-splicing by excluding proteins sensitive to reducing conditions, such as those containing critical disulfide bonds. Here we report the discovery, characterization, and engineering of a completely cysteine-less split intein (CL intein) that is capable of efficient trans-splicing at ambient temperatures, without a denaturation step, and in the absence of reducing agents. We demonstrate its utility for the site-specific chemical modification of nanobodies and an antibody Fc fragment by N- and C-terminal trans-splicing with short peptide tags (CysTag) that consist of only a few amino acids and have been prelabeled on a single cysteine using classical cysteine bioconjugation. We also synthesized the short N-terminal fragment of the atypically split CL intein by solid-phase peptide synthesis. Furthermore, using the CL intein in combination with a nanobody-epitope pair as a high-affinity mediator, we showed chemical labeling of the extracellular domain of a cell surface receptor on living mammalian cells with a short CysTag containing a synthetic fluorophore. The CL intein thus greatly expands the scope of applications for protein trans-splicing.
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7
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Palei S, Becher KS, Nienberg C, Jose J, Mootz HD. Bacterial Cell-Surface Display of Semisynthetic Cyclic Peptides. Chembiochem 2018; 20:72-77. [PMID: 30216604 DOI: 10.1002/cbic.201800552] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Indexed: 01/20/2023]
Abstract
Semisynthetic cyclic peptides containing both non-proteinogenic building blocks, as the synthetic part, and a genetically encoded sequence amenable to DNA-based randomization hold great potential to expand the chemical space in the quest for novel bioactive peptides. Key to an efficient selection of novel binders to biomacromolecules is a robust method to link their genotype and phenotype. A novel bacterial cell surface display technology has been developed to present cyclic peptides composed of synthetic and genetically encoded fragments in their backbones. The fragments were combined by protein trans-splicing and intramolecular oxime ligation. To this end, a split intein half and an unnatural amino acid were displayed with the genetically encoded part on the surface of Escherichia coli. Addition of the synthetic fragment equipped with the split intein partner and an aminooxy moiety, as well as the application of a pH-shift protocol, resulted in the onsurface formation of the semisynthetic cyclic peptide. This approach will serve for the generation of cyclic peptide libraries suitable for selection by fluorescence-activated cell sorting, and more generally enables chemical modification of proteins on the bacterial surface.
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Affiliation(s)
- Shubhendu Palei
- Institute of Biochemistry, University of Muenster, Wilhelm-Klemm-Strasse 2, 48149, Münster, Germany.,International Graduate School of Chemistry (GSC-MS), University of Münster, 48149, Münster, Germany
| | - Kira S Becher
- Institute of Biochemistry, University of Muenster, Wilhelm-Klemm-Strasse 2, 48149, Münster, Germany
| | - Christian Nienberg
- Institute of Pharmaceutical and Medicinal Chemistry, University of Muenster, PharmaCampus, 48149, Münster, Germany
| | - Joachim Jose
- Institute of Pharmaceutical and Medicinal Chemistry, University of Muenster, PharmaCampus, 48149, Münster, Germany.,International Graduate School of Chemistry (GSC-MS), University of Münster, 48149, Münster, Germany
| | - Henning D Mootz
- Institute of Biochemistry, University of Muenster, Wilhelm-Klemm-Strasse 2, 48149, Münster, Germany.,International Graduate School of Chemistry (GSC-MS), University of Münster, 48149, Münster, Germany
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8
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Lee E, Min K, Chang YT, Kwon Y. Efficient and wash-free labeling of membrane proteins using engineered Npu DnaE split-inteins. Protein Sci 2018; 27:1568-1574. [PMID: 30151847 DOI: 10.1002/pro.3455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 01/01/2023]
Abstract
An efficient and wash-free method to conjugate a fluorescent tag to a target membrane protein is developed, using engineered Npu DnaE split-inteins. This approach allowed fast labeling while avoiding the strenuous synthesis of a long polypeptide. Two different modes of labeling, namely specific binding and covalent conjugation, are observed. The covalent labeling was monitored within 5 min, without background staining.
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Affiliation(s)
- Euiyeon Lee
- Department of Biomedical Engineering, Dongguk University, Seoul, 04620, South Korea
| | - Kyoungmi Min
- Department of Biomedical Engineering, Dongguk University, Seoul, 04620, South Korea
| | - Young-Tae Chang
- Center for Self-assembly and Complexity, Institute for Basic Science (IBS), Pohang, 37673, South Korea.,Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Youngeun Kwon
- Department of Biomedical Engineering, Dongguk University, Seoul, 04620, South Korea
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9
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Ghosh U, Yau WM, Tycko R. Coexisting order and disorder within a common 40-residue amyloid-β fibril structure in Alzheimer's disease brain tissue. Chem Commun (Camb) 2018; 54:5070-5073. [PMID: 29707712 PMCID: PMC5953852 DOI: 10.1039/c8cc01967c] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Fibrils formed by 40- and 42-residue amyloid-β (Aβ40 and Aβ42) peptides exhibit molecular-level structural polymorphisms. A recent screen of fibrils derived from brain tissue of Alzheimer's disease patients revealed a single predominant Aβ40 polymorph. We present solid state nuclear magnetic resonance (ssNMR) data that define its coexisting structurally ordered and disordered segments.
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Affiliation(s)
- Ujjayini Ghosh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 5, Room 409, Bethesda, Maryland 20892-0520, USA.
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10
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Li X, Zhang XL, Cai YM, Zhang L, Lin Y, Meng Q. Site specific labeling of two proteins in one system by atypical split inteins. Int J Biol Macromol 2018; 109:921-931. [DOI: 10.1016/j.ijbiomac.2017.11.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/06/2017] [Accepted: 11/12/2017] [Indexed: 01/25/2023]
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11
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Kadina A, Kietrys AM, Kool ET. RNA Cloaking by Reversible Acylation. Angew Chem Int Ed Engl 2018; 57:3059-3063. [PMID: 29370460 PMCID: PMC5842138 DOI: 10.1002/anie.201708696] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 01/18/2018] [Indexed: 11/08/2022]
Abstract
We describe a selective and mild chemical approach for controlling RNA hybridization, folding, and enzyme interactions. Reaction of RNAs in aqueous buffer with an azide-substituted acylating agent (100-200 mm) yields several 2'-OH acylations per RNA strand in as little as 10 min. This poly-acylated ("cloaked") RNA is strongly blocked from hybridization with complementary nucleic acids, from cleavage by RNA-processing enzymes, and from folding into active aptamer structures. Importantly, treatment with a water-soluble phosphine triggers a Staudinger reduction of the azide groups, resulting in spontaneous loss of acyl groups ("uncloaking"). This fully restores RNA folding and biochemical activity.
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Affiliation(s)
- Anastasia Kadina
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Anna M Kietrys
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Eric T Kool
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
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12
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Affiliation(s)
- Anastasia Kadina
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
| | - Anna M. Kietrys
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
| | - Eric T. Kool
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
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13
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Li G, Yuan S, Zheng S, Liu Y, Huang G. In Situ Living Cell Protein Analysis by Single-Step Mass Spectrometry. Anal Chem 2018; 90:3409-3415. [DOI: 10.1021/acs.analchem.7b05055] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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14
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Schneider AFL, Hackenberger CPR. Fluorescent labelling in living cells. Curr Opin Biotechnol 2017; 48:61-68. [PMID: 28395178 DOI: 10.1016/j.copbio.2017.03.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/10/2017] [Indexed: 11/15/2022]
Abstract
The labelling of proteins with green fluorescent protein enabled the visualization of proteins in living cells for the first time. Since then, much progress has been made in the field. Modern strategies allow the labelling of proteins in live cells through a range of specialized methods with sophisticated chemical probes that show enhanced photophysical properties compared to fluorescent proteins. This review briefly summarizes recent advances in the field of fluorescent chemical protein labelling inside living cells and illustrates key aspects on the requirements and advantages of each given method.
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Affiliation(s)
- Anselm Fabian Lowell Schneider
- Leibniz-Institut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, D-13125 Berlin, Germany
| | - Christian Peter Richard Hackenberger
- Leibniz-Institut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, D-13125 Berlin, Germany; Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Str. 2, D-12489 Berlin, Germany.
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15
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Bachmann AL, Mootz HD. N-terminal chemical protein labeling using the naturally split GOS-TerL intein. J Pept Sci 2017; 23:624-630. [PMID: 28332258 DOI: 10.1002/psc.2996] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 11/07/2022]
Abstract
Chemoselective and regioselective chemical protein labeling is of great importance, yet no current technique is sufficiently general and simple to perform. Protein trans-splicing by split inteins can be used to ligate short tags with chemical labels to either the N or the C terminus of a protein. The CysTag approach exploits split intein fragments without a cysteine fused with such a short tag containing a single cysteine that is easily amenable to selective modification using classical cysteine bioconjugation. Labeling of the protein of interest is achieved through transfer of the pre-labeled tag by protein trans-splicing. This protocol keeps other cysteines unmodified. While split inteins for C-terminal CysTag labeling were previously reported, no high-yielding and naturally split intein for N-terminal labeling has been available. In this work, the recently discovered GOS-TerL intein was explored as the only known naturally split intein that both lacks a cysteine in its N-terminal fragment and is active under ambient conditions. Thioredoxin as a model protein and a camelid nanobody were labeled with a synthetic fluorophore by transferring the pre-labeling CysTag in the protein trans-splicing reaction with yields of about 50 to 90%. The short N-terminal intein fragment was also chemically synthesized with a tag to enable protein labeling by semi-synthetic protein trans-splicing. Our results expand the scope of the CysTag labeling strategy, which achieves selective chemical modification without the requirement for sophisticated biorthogonal functional groups and rather builds on the plethora of commercially available reagents directed at the thiol side chain of cysteine. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
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Affiliation(s)
- Anne-Lena Bachmann
- Institute of Biochemistry, University of Muenster, Wilhelm-Klemm-Str. 2, 48149, Münster, Germany
| | - Henning D Mootz
- Institute of Biochemistry, University of Muenster, Wilhelm-Klemm-Str. 2, 48149, Münster, Germany
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16
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Abstract
Over the years, there have been remarkable efforts in the development of selective protein labeling strategies. In this review, we deliver a comprehensive overview of the currently available bioorthogonal and chemoselective reactions. The ability to introduce bioorthogonal handles to proteins is essential to carry out bioorthogonal reactions for protein labeling in living systems. We therefore summarize the techniques that allow for site-specific "installation" of bioorthogonal handles into proteins. We also highlight the biological applications that have been achieved by selective chemical labeling of proteins.
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Affiliation(s)
- Xi Chen
- Chemical Genomics Centre of the Max Planck Society, Otto-Hahn-Str. 15, 44227 Dortmund, Germany
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17
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Braner M, Kollmannsperger A, Wieneke R, Tampé R. 'Traceless' tracing of proteins - high-affinity trans-splicing directed by a minimal interaction pair. Chem Sci 2015; 7:2646-2652. [PMID: 28660037 PMCID: PMC5477019 DOI: 10.1039/c5sc02936h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 12/18/2015] [Indexed: 12/26/2022] Open
Abstract
Using a minimal lock-and-key element the affinity between the intein fragments for N-terminal protein trans-splicing was significantly increased, allowing for site-specific, ‘traceless’ covalent protein labeling in living mammalian cells at nanomolar probe concentrations.
Protein trans-splicing mediated by split inteins is a powerful technique for site-specific protein modification. Despite recent developments there is still an urgent need for ultra-small high-affinity intein tags for in vitro and in vivo approaches. To date, only very few in-cell applications of protein trans-splicing have been reported, all limited to C-terminal protein modifications. Here, we developed a strategy for covalent N-terminal intein-mediated protein labeling at (sub) nanomolar probe concentrations. Combined with a minimal synthetic lock-and-key element, the affinity between the intein fragments was increased more than 50-fold to 10 nM. Site-specific and efficient ‘traceless’ protein modification by high-affinity trans-splicing is demonstrated at nanomolar concentrations in living mammalian cells.
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Affiliation(s)
- M Braner
- Institute of Biochemistry, Biocenter, and Cluster of Excellence - Macromolecular Complexes , Goethe-University Frankfurt , Max-von-Laue-Str. 9 , 60438 Frankfurt/M. , Germany .
| | - A Kollmannsperger
- Institute of Biochemistry, Biocenter, and Cluster of Excellence - Macromolecular Complexes , Goethe-University Frankfurt , Max-von-Laue-Str. 9 , 60438 Frankfurt/M. , Germany .
| | - R Wieneke
- Institute of Biochemistry, Biocenter, and Cluster of Excellence - Macromolecular Complexes , Goethe-University Frankfurt , Max-von-Laue-Str. 9 , 60438 Frankfurt/M. , Germany .
| | - R Tampé
- Institute of Biochemistry, Biocenter, and Cluster of Excellence - Macromolecular Complexes , Goethe-University Frankfurt , Max-von-Laue-Str. 9 , 60438 Frankfurt/M. , Germany .
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18
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Reinhardt U, Lotze J, Mörl K, Beck-Sickinger AG, Seitz O. Rapid Covalent Fluorescence Labeling of Membrane Proteins on Live Cells via Coiled-Coil Templated Acyl Transfer. Bioconjug Chem 2015; 26:2106-17. [PMID: 26367072 DOI: 10.1021/acs.bioconjchem.5b00387] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Fluorescently labeled proteins enable the microscopic imaging of protein localization and function in live cells. In labeling reactions targeted against specific tag sequences, the size of the fluorophore-tag is of major concern. The tag should be small to prevent interference with protein function. Furthermore, rapid and covalent labeling methods are desired to enable the analysis of fast biological processes. Herein, we describe the development of a method in which the formation of a parallel coiled coil triggers the transfer of a fluorescence dye from a thioester-linked coil peptide conjugate onto a cysteine-modified coil peptide. This labeling method requires only small tag sequences (max 23 aa) and occurs with high tag specificity. We show that size matching of the coil peptides and a suitable thioester reactivity allow the acyl transfer reaction to proceed within minutes (rather than hours). We demonstrate the versatility of this method by applying it to the labeling of different G-protein coupled membrane receptors including the human neuropeptide Y receptors 1, 2, 4, 5, the neuropeptide FF receptors 1 and 2, and the dopamine receptor 1. The labeled receptors are fully functional and able to bind the respective ligand with high affinity. Activity is not impaired as demonstrated by activation, internalization, and recycling experiments.
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Affiliation(s)
- Ulrike Reinhardt
- Institut für Chemie, Humboldt-Universität zu Berlin , Brook-Taylor-Strasse 2, D-12489 Berlin, Germany
| | - Jonathan Lotze
- Institut für Biochemie, Universität Leipzig , Brüderstrasse 34, D-04103 Leipzig, Germany
| | - Karin Mörl
- Institut für Biochemie, Universität Leipzig , Brüderstrasse 34, D-04103 Leipzig, Germany
| | | | - Oliver Seitz
- Institut für Chemie, Humboldt-Universität zu Berlin , Brook-Taylor-Strasse 2, D-12489 Berlin, Germany
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Bachmann AL, Matern JCJ, Schütz V, Mootz HD. Chemical-tag labeling of proteins using fully recombinant split inteins. Methods Mol Biol 2015; 1266:145-159. [PMID: 25560073 DOI: 10.1007/978-1-4939-2272-7_10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Chemical-tag labeling of proteins involving split inteins is an approach for the selective chemical modification of proteins without the requirement of any chemical synthesis to be performed. In a two-step protocol, a very short tag fused to a split intein auxiliary protein is first labeled in a bioconjugation reaction with a synthetic moiety either at its N-terminus (amine-tag) or at the side chain of an unnatural amino acid (click-tag). The labeled protein is then mixed with the protein of interest fused to the complementary intein fragment. In the resulting spontaneous protein trans-splicing reaction the split intein fragments remove themselves and ligate the tag to the protein of interest in a virtually traceless fashion. The reaction can be performed either using a purified protein of interest or to label a protein in the context of a living cell. All protein components are recombinantly expressed and all chemical reagents are commercially available.
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Affiliation(s)
- Anne-Lena Bachmann
- Department of Chemistry and Pharmacy, Institute of Biochemistry, University of Muenster, Wilhelm-Klemm-Str. 2, 48149, Münster, Germany
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