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Caldwell SJ, Haydon IC, Piperidou N, Huang PS, Bick MJ, Sjöström HS, Hilvert D, Baker D, Zeymer C. Tight and specific lanthanide binding in a de novo TIM barrel with a large internal cavity designed by symmetric domain fusion. Proc Natl Acad Sci U S A 2020; 117:30362-30369. [PMID: 33203677 PMCID: PMC7720202 DOI: 10.1073/pnas.2008535117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
De novo protein design has succeeded in generating a large variety of globular proteins, but the construction of protein scaffolds with cavities that could accommodate large signaling molecules, cofactors, and substrates remains an outstanding challenge. The long, often flexible loops that form such cavities in many natural proteins are difficult to precisely program and thus challenging for computational protein design. Here we describe an alternative approach to this problem. We fused two stable proteins with C2 symmetry-a de novo designed dimeric ferredoxin fold and a de novo designed TIM barrel-such that their symmetry axes are aligned to create scaffolds with large cavities that can serve as binding pockets or enzymatic reaction chambers. The crystal structures of two such designs confirm the presence of a 420 cubic Ångström chamber defined by the top of the designed TIM barrel and the bottom of the ferredoxin dimer. We functionalized the scaffold by installing a metal-binding site consisting of four glutamate residues close to the symmetry axis. The protein binds lanthanide ions with very high affinity as demonstrated by tryptophan-enhanced terbium luminescence. This approach can be extended to other metals and cofactors, making this scaffold a modular platform for the design of binding proteins and biocatalysts.
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Affiliation(s)
- Shane J Caldwell
- Department of Biochemistry, University of Washington, Seattle, WA 98195
- Institute for Protein Design, University of Washington, Seattle, WA 98195
| | - Ian C Haydon
- Department of Biochemistry, University of Washington, Seattle, WA 98195
- Institute for Protein Design, University of Washington, Seattle, WA 98195
| | - Nikoletta Piperidou
- Laboratory of Organic Chemistry, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland
| | - Po-Ssu Huang
- Department of Biochemistry, University of Washington, Seattle, WA 98195
- Institute for Protein Design, University of Washington, Seattle, WA 98195
- Department of Bioengineering, Stanford University, Shriram Center for Bioengineering and Chemical Engineering, Stanford, CA 94305
| | - Matthew J Bick
- Department of Biochemistry, University of Washington, Seattle, WA 98195
- Institute for Protein Design, University of Washington, Seattle, WA 98195
| | - H Sebastian Sjöström
- Laboratory of Organic Chemistry, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA 98195;
- Institute for Protein Design, University of Washington, Seattle, WA 98195
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195
| | - Cathleen Zeymer
- Laboratory of Organic Chemistry, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland;
- Department of Chemistry, Technische Universität München, 85747 Garching, Germany
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Hetrick KJ, Aguilar Ramos MA, Raines RT. Terbium(III) Luminescence-Based Assay for Esterase Activity. Anal Chem 2019; 91:8615-8621. [PMID: 31247727 DOI: 10.1021/acs.analchem.9b01954] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Esterases catalyze the hydrolysis of esters to form a carboxylic acid and alcohol. These enzymes play a key role in both the detoxification of xenobiotic compounds and the metabolism of drugs and prodrugs. Numerous fluorogenic probes have been developed to monitor esterase activity. Most are based on an aromatic alcohol, and the others are based on an aromatic acid. These restrictions leave unexplored the specificity of esterases for aliphatic esters. Here, we report on the use of esters of thiopheneacetic acid coupled with the luminescence of terbium(III) as the basis for a continuous assay of esterase activity. This probe allows for a wide variation of the alcohol moiety and the detection of its hydrolysis at submicromolar concentrations. The assay verifies steady-state kinetic parameters for catalysis by pig liver esterase from either initial rates or the integration of progress curves, and its utility is evident with unpurified esterases in bacterial and human cell lysates.
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Affiliation(s)
- Kenton J Hetrick
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States.,Broad Institute of MIT and Harvard , Cambridge , Massachusetts 02142 , United States
| | - Miguel A Aguilar Ramos
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Ronald T Raines
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States.,Broad Institute of MIT and Harvard , Cambridge , Massachusetts 02142 , United States
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Bhattacharya K, Bernasconi L, Picard D. Luminescence resonance energy transfer between genetically encoded donor and acceptor for protein-protein interaction studies in the molecular chaperone HSP70/HSP90 complexes. Sci Rep 2018; 8:2801. [PMID: 29434293 PMCID: PMC5809404 DOI: 10.1038/s41598-018-21210-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/31/2018] [Indexed: 12/11/2022] Open
Abstract
Complex patterns of protein-protein interactions (PPInts) are involved in almost all cellular processes. This has stimulated the development of a wide range of methods to characterize PPInts in detail. Methods with fluorescence resonance energy transfer can be technically challenging and suffer from several limitations, which could be overcome by switching to luminescence resonance energy transfer (LRET) with lanthanide ions such as Tb3+. With LRET, energy transfer between PPInt partners works over a larger distance and with less topological constraints; moreover, the long-lived luminescence of lanthanides allows one to bypass the short-lived background fluorescence. We have developed a novel LRET method to investigate PPInts between partners expressed as fusion proteins with genetically encoded donor and acceptor moieties. Upon UV excitation of a tryptophan within a lanthanide binding peptide, the Tb3+ luminescence is harnessed to excite either a green or a red fluorescent protein. We demonstrate the usefulness of the LRET assay by applying it to analyze the interactions of the molecular chaperones HSP70 and HSP90 with their common co-chaperone HOP/Sti1. We recapitulate the previously described interaction specificities between the HSP70/HSP90 C-termini and tetratricopeptide repeat domains of HOP/Sti1 and demonstrate the impact of single point mutants on domain-domain interactions.
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Affiliation(s)
- Kaushik Bhattacharya
- Département de Biologie Cellulaire, Université de Genève, 30 Quai Ernest-Ansermet, Sciences III, 1211 Genève 4, Switzerland
| | - Lilia Bernasconi
- Département de Biologie Cellulaire, Université de Genève, 30 Quai Ernest-Ansermet, Sciences III, 1211 Genève 4, Switzerland
| | - Didier Picard
- Département de Biologie Cellulaire, Université de Genève, 30 Quai Ernest-Ansermet, Sciences III, 1211 Genève 4, Switzerland.
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Bag SS, Yashmeen A. Uracil-amino acid as a scaffold for β-sheet peptidomimetics: Study of photophysics and interaction with BSA protein. Bioorg Med Chem Lett 2017; 27:5387-5392. [PMID: 29153423 DOI: 10.1016/j.bmcl.2017.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 11/05/2017] [Accepted: 11/08/2017] [Indexed: 10/18/2022]
Abstract
We report herein the uracil-di-aza-amino acid (UrAA) as a new family of molecular scaffold to induce β-hairpin structure with H-bonded β-sheet conformation in a short peptide. This has been demonstrated in two conceptual fluorescent pentapeptides wherein triazolylpyrenyl alanine and/or triazolylmethoxynapthyl alanine (TPyAlaDo and/or TMNapAlaDo) are embedded into two arms of the uracil-amino acid via an intervening leucine. Conformational analysis by CD, IR, variable temperature and 2D NMR spectroscopy reveals the β-hairpin structures for both the peptides. Study of photophysical property reveals that the pentapeptide containing fluorescent triazolyl unnatural amino acids TMNapAlaDo and TPyAlaDo at the two termini exhibits dual path entry to exciplex emission-either via FRET from TMNapAlaDo to TPyAlaDo or via direct excitation of a FRET acceptor, TPyAlaDo. The other pentapeptide with TPyAlaDo/TPyAlaDo pair shows excimer emission. Furthermore, both the peptides maintaining their fundamental photophysics are found to interact with BSA as only a test biomolecule.
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Affiliation(s)
- Subhendu Sekhar Bag
- Bioorganic Chemistry Laboratory, Department of Chemistry, Indian Institute of Technology Guwahati, North Guwhati 781039, Assam, India.
| | - Afsana Yashmeen
- Bioorganic Chemistry Laboratory, Department of Chemistry, Indian Institute of Technology Guwahati, North Guwhati 781039, Assam, India
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Bag SS, Jana S, Pradhan MK. Synthesis, photophysical properties of triazolyl-donor/acceptor chromophores decorated unnatural amino acids: Incorporation of a pair into Leu-enkephalin peptide and application of triazolylperylene amino acid in sensing BSA. Bioorg Med Chem 2016; 24:3579-95. [DOI: 10.1016/j.bmc.2016.05.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 05/29/2016] [Accepted: 05/30/2016] [Indexed: 02/03/2023]
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Bag SS, Jana S, Pradhan MK, Pal S. Trichromophoric pentapeptide: impact of β-sheet conformation on dual path to excimer emission and sensing of BSA. RSC Adv 2016. [DOI: 10.1039/c6ra14084j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We established dual mechanisms for excimer emission-either via FRET or direct excitation of a FRET acceptor- in a conceptually novel trichromophoric pentapeptide which serves as an effective fluorescence light-up probe for protein–peptide interaction.
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Affiliation(s)
- Subhendu Sekhar Bag
- Bioorganic Chemistry Laboratory
- Department of Chemistry
- Indian Institute of Technology Guwahati
- North Guwhati-781039
- India
| | - Subhashis Jana
- Bioorganic Chemistry Laboratory
- Department of Chemistry
- Indian Institute of Technology Guwahati
- North Guwhati-781039
- India
| | - Manoj Kumar Pradhan
- Bioorganic Chemistry Laboratory
- Department of Chemistry
- Indian Institute of Technology Guwahati
- North Guwhati-781039
- India
| | - Sunit Pal
- Bioorganic Chemistry Laboratory
- Department of Chemistry
- Indian Institute of Technology Guwahati
- North Guwhati-781039
- India
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Barb AW, Subedi GP. An encodable lanthanide binding tag with reduced size and flexibility for measuring residual dipolar couplings and pseudocontact shifts in large proteins. JOURNAL OF BIOMOLECULAR NMR 2016; 64:75-85. [PMID: 26728077 PMCID: PMC4884023 DOI: 10.1007/s10858-015-0009-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 12/28/2015] [Indexed: 05/03/2023]
Abstract
Metal ions serve important roles in structural biology applications from long-range perturbations seen in magnetic resonance experiments to electron-dense signatures in X-ray crystallography data; however, the metal ion must be secured in a molecular framework to achieve the maximum benefit. Polypeptide-based lanthanide-binding tags (LBTs) represent one option that can be directly encoded within a recombinant protein expression construct. However, LBTs often exhibit significant mobility relative to the target molecule. Here we report the characterization of improved LBTs sequences for insertion into a protein loop. These LBTs were inserted to connect two parallel alpha helices of an immunoglobulin G (IgG)-binding Z domain platform. Variants A and B bound Tb(3+) with high affinity (0.70 and 0.13 μM, respectively) and displayed restricted LBT motion. Compared to the parent construct, the metal-bound A experienced a 2.5-fold reduction in tag motion as measured by magnetic field-induced residual dipolar couplings and was further studied in a 72.2 kDa complex with the human IgG1 fragment crystallizable (IgG1 Fc) glycoprotein. The appearance of both pseudo-contact shifts (-0.221 to 0.081 ppm) and residual dipolar couplings (-7.6 to 14.3 Hz) of IgG1 Fc resonances in the IgG1 Fc:(variant A:Tb(3+))2 complex indicated structural restriction of the LBT with respect to the Fc. These studies highlight the applicability of improved LBT sequences with reduced mobility to probe the structure of macromolecular systems.
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Affiliation(s)
- Adam W Barb
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, IA, 50011, USA.
| | - Ganesh P Subedi
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, 2214 Molecular Biology Building, Ames, IA, 50011, USA
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