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Ju H, Cheng L, Li M, Mei K, He S, Jia C, Guo X. Single-Molecule Electrical Profiling of Peptides and Proteins. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2401877. [PMID: 38639403 PMCID: PMC11267281 DOI: 10.1002/advs.202401877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/03/2024] [Indexed: 04/20/2024]
Abstract
In recent decades, there has been a significant increase in the application of single-molecule electrical analysis platforms in studying proteins and peptides. These advanced analysis methods have the potential for deep investigation of enzymatic working mechanisms and accurate monitoring of dynamic changes in protein configurations, which are often challenging to achieve in ensemble measurements. In this work, the prominent research progress in peptide and protein-related studies are surveyed using electronic devices with single-molecule/single-event sensitivity, including single-molecule junctions, single-molecule field-effect transistors, and nanopores. In particular, the successful commercial application of nanopores in DNA sequencing has made it one of the most promising techniques in protein sequencing at the single-molecule level. From single peptides to protein complexes, the correlation between their electrical characteristics, structures, and biological functions is gradually being established. This enables to distinguish different molecular configurations of these biomacromolecules through real-time electrical monitoring of their life activities, significantly improving the understanding of the mechanisms underlying various life processes.
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Affiliation(s)
- Hongyu Ju
- School of Pharmaceutical Science and TechnologyTianjin UniversityTianjin300072P. R. China
- Center of Single‐Molecule SciencesInstitute of Modern OpticsFrontiers Science Center for New Organic MatterTianjin Key Laboratory of Microscale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai UniversityTianjin300350P. R. China
| | - Li Cheng
- Center of Single‐Molecule SciencesInstitute of Modern OpticsFrontiers Science Center for New Organic MatterTianjin Key Laboratory of Microscale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai UniversityTianjin300350P. R. China
| | - Mengmeng Li
- Center of Single‐Molecule SciencesInstitute of Modern OpticsFrontiers Science Center for New Organic MatterTianjin Key Laboratory of Microscale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai UniversityTianjin300350P. R. China
| | - Kunrong Mei
- School of Pharmaceutical Science and TechnologyTianjin UniversityTianjin300072P. R. China
| | - Suhang He
- Center of Single‐Molecule SciencesInstitute of Modern OpticsFrontiers Science Center for New Organic MatterTianjin Key Laboratory of Microscale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai UniversityTianjin300350P. R. China
| | - Chuancheng Jia
- Center of Single‐Molecule SciencesInstitute of Modern OpticsFrontiers Science Center for New Organic MatterTianjin Key Laboratory of Microscale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai UniversityTianjin300350P. R. China
| | - Xuefeng Guo
- Center of Single‐Molecule SciencesInstitute of Modern OpticsFrontiers Science Center for New Organic MatterTianjin Key Laboratory of Microscale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai UniversityTianjin300350P. R. China
- Beijing National Laboratory for Molecular SciencesNational Biomedical Imaging CenterCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871P. R. China
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2
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Wolff AM, Nango E, Young ID, Brewster AS, Kubo M, Nomura T, Sugahara M, Owada S, Barad BA, Ito K, Bhowmick A, Carbajo S, Hino T, Holton JM, Im D, O'Riordan LJ, Tanaka T, Tanaka R, Sierra RG, Yumoto F, Tono K, Iwata S, Sauter NK, Fraser JS, Thompson MC. Mapping protein dynamics at high spatial resolution with temperature-jump X-ray crystallography. Nat Chem 2023; 15:1549-1558. [PMID: 37723259 PMCID: PMC10624634 DOI: 10.1038/s41557-023-01329-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 08/17/2023] [Indexed: 09/20/2023]
Abstract
Understanding and controlling protein motion at atomic resolution is a hallmark challenge for structural biologists and protein engineers because conformational dynamics are essential for complex functions such as enzyme catalysis and allosteric regulation. Time-resolved crystallography offers a window into protein motions, yet without a universal perturbation to initiate conformational changes the method has been limited in scope. Here we couple a solvent-based temperature jump with time-resolved crystallography to visualize structural motions in lysozyme, a dynamic enzyme. We observed widespread atomic vibrations on the nanosecond timescale, which evolve on the submillisecond timescale into localized structural fluctuations that are coupled to the active site. An orthogonal perturbation to the enzyme, inhibitor binding, altered these dynamics by blocking key motions that allow energy to dissipate from vibrations into functional movements linked to the catalytic cycle. Because temperature jump is a universal method for perturbing molecular motion, the method demonstrated here is broadly applicable for studying protein dynamics.
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Affiliation(s)
- Alexander M Wolff
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA
| | - Eriko Nango
- RIKEN SPring-8 Center, Sayo-gun, Japan.
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Aoba-ku, Japan.
| | - Iris D Young
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Aaron S Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Minoru Kubo
- RIKEN SPring-8 Center, Sayo-gun, Japan
- Department of Life Science, Graduate School of Science, University of Hyogo, Hyogo, Japan
| | - Takashi Nomura
- RIKEN SPring-8 Center, Sayo-gun, Japan
- Department of Life Science, Graduate School of Science, University of Hyogo, Hyogo, Japan
| | | | | | - Benjamin A Barad
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Integrative Structural and Computational Biology, Scripps Research, San Diego, CA, USA
| | - Kazutaka Ito
- Laboratory for Drug Discovery, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Izunokuni-shi, Japan
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sergio Carbajo
- SLAC National Accelerator Laboratory, Linac Coherent Light Source, Menlo Park, CA, USA
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - Tomoya Hino
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
- Center for Research on Green Sustainable Chemistry, Tottori University, Tottori, Japan
| | - James M Holton
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dohyun Im
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Japan
| | - Lee J O'Riordan
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Tomoyuki Tanaka
- RIKEN SPring-8 Center, Sayo-gun, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Japan
| | - Rie Tanaka
- RIKEN SPring-8 Center, Sayo-gun, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Japan
| | - Raymond G Sierra
- SLAC National Accelerator Laboratory, Linac Coherent Light Source, Menlo Park, CA, USA
| | - Fumiaki Yumoto
- Structural Biology Research Center, Institute of Materials Structure Science, KEK/High Energy Accelerator Research Organization, Tsukuba, Japan
- Ginward Japan K.K., Tokyo, Japan
| | - Kensuke Tono
- RIKEN SPring-8 Center, Sayo-gun, Japan
- Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - So Iwata
- RIKEN SPring-8 Center, Sayo-gun, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Japan
| | - Nicholas K Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Michael C Thompson
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA, USA.
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3
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Premetis GE, Georgakis ND, Stathi A, Labrou NE. Metaviromics analysis of marine biofilm reveals a glycoside hydrolase endolysin with high specificity towards Acinetobacter baumannii. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140918. [PMID: 37150474 DOI: 10.1016/j.bbapap.2023.140918] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
Multidrug-resistant (MDR) bacteria are a growing threat to the public health. Among them, the Gram-negative Acinetobacter baumannii is considered today as the most dangerous MDR pathogen. Phage-derived endolysins are peptidoglycan (PG) hydrolytic enzymes that can function as effective tools in the fight against MDR bacteria. In the present work, the viral diversity of a marine environmental sample (biofilm), formed near an industrial zone, was mined for the identification of a putative endolysin (AbLys2) that belongs to the glycoside hydrolase family 24 (GH24, EC 3.2.1.17). The coding sequence of AbLys2 was cloned and expressed in E. coli. The lytic activity and specificity of the recombinant enzyme were evaluated against suspensions of a range of Gram-positive and Gram-negative human pathogens using turbidity assays. AbLys2 displayed enhanced selectivity towards A. baumannii cells, compared to other bacteria. Kinetics analysis was carried out to characterize the dependence of its lytic activity on pH and showed that the enzyme exhibits its maximal activity at pH 5.5. Thermostability analysis showed that AbLys2 displays melting temperature Tm 47.1 °C. Florescence microscopy and cell viability assays established that AbLys2 is active towards live cultures of A. baumannii cells with an inhibitory concentration IC50 3.41 ± 0.09 μM. Molecular modeling allowed the prediction of important amino acid residues involved in catalysis. The results of the present study suggest that AbLys2 provides efficient lytic and antimicrobial activity towards A. baumannii cells and therefore is a promising new antimicrobial against this pathogen.
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Affiliation(s)
- Georgios E Premetis
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 -Athens, Greece
| | - Nikolaos D Georgakis
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 -Athens, Greece
| | - Angeliki Stathi
- Department of Microbiology, "Aghia Sophia" Children's Hospital, 11527 Athens, Greece
| | - Nikolaos E Labrou
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 -Athens, Greece.
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4
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He J, Dmochowski IJ. Local Xenon-Protein Interaction Produces Global Conformational Change and Allosteric Inhibition in Lysozyme. Biochemistry 2023; 62:1659-1669. [PMID: 37192381 PMCID: PMC10821772 DOI: 10.1021/acs.biochem.3c00046] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Noble gases have well-established biological effects, yet their molecular mechanisms remain poorly understood. Here, we investigated, both experimentally and computationally, the molecular modes of xenon (Xe) action in bacteriophage T4 lysozyme (T4L). By combining indirect gassing methods with a colorimetric lysozyme activity assay, a reversible, Xe-specific (20 ± 3)% inhibition effect was observed. Accelerated molecular dynamic simulations revealed that Xe exerts allosteric inhibition on the protein by expanding a C-terminal hydrophobic cavity. Xe-induced cavity expansion results in global conformational changes, with long-range transduction distorting the active site where peptidoglycan binds. Interestingly, the peptide substrate binding site that enables lysozyme specificity does not change conformation. Two T4L mutants designed to reshape the C-terminal Xe cavity established a correlation between cavity expansion and enzyme inhibition. This work also highlights the use of Xe flooding simulations to identify new cryptic binding pockets. These results enrich our understanding of Xe-protein interactions at the molecular level and inspire further biochemical investigations with noble gases.
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Affiliation(s)
- Jiayi He
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Ivan J Dmochowski
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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5
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Jang SS, Dubnik S, Hon J, Hellenkamp B, Lynall DG, Shepard KL, Nuckolls C, Gonzalez RL. Characterizing the Conformational Free-Energy Landscape of RNA Stem-Loops Using Single-Molecule Field-Effect Transistors. J Am Chem Soc 2023; 145:402-412. [PMID: 36547391 PMCID: PMC10025942 DOI: 10.1021/jacs.2c10218] [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: 12/24/2022]
Abstract
We have developed and used single-molecule field-effect transistors (smFETs) to characterize the conformational free-energy landscape of RNA stem-loops. Stem-loops are one of the most common RNA structural motifs and serve as building blocks for the formation of complex RNA structures. Given their prevalence and integral role in RNA folding, the kinetics of stem-loop (un)folding has been extensively characterized using both experimental and computational approaches. Interestingly, these studies have reported vastly disparate timescales of (un)folding, which has been interpreted as evidence that (un)folding of even simple stem-loops occurs on a highly rugged conformational energy landscape. Because smFETs do not rely on fluorophore reporters of conformation or mechanical (un)folding forces, they provide a unique approach that has allowed us to directly monitor tens of thousands of (un)folding events of individual stem-loops at a 200 μs time resolution. Our results show that under our experimental conditions, stem-loops (un)fold over a 1-200 ms timescale during which they transition between ensembles of unfolded and folded conformations, the latter of which is composed of at least two sub-populations. The 1-200 ms timescale of (un)folding we observe here indicates that smFETs report on complete (un)folding trajectories in which unfolded conformations of the RNA spend long periods of time wandering the free-energy landscape before sampling one of several misfolded conformations or the natively folded conformation. Our findings highlight the extremely rugged landscape on which even the simplest RNA structural elements fold and demonstrate that smFETs are a unique and powerful approach for characterizing the conformational free-energy of RNA.
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Affiliation(s)
- Sukjin S. Jang
- Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA
| | - Sarah Dubnik
- Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA
| | - Jason Hon
- Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA
| | - Björn Hellenkamp
- Department of Electrical Engineering, Columbia University, 3000 Broadway, New York, 10027, USA
| | - David G. Lynall
- Department of Electrical Engineering, Columbia University, 3000 Broadway, New York, 10027, USA
| | - Kenneth L. Shepard
- Department of Electrical Engineering, Columbia University, 3000 Broadway, New York, 10027, USA
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA
| | - Ruben L. Gonzalez
- Department of Chemistry, Columbia University, 3000 Broadway, New York, NY 10027, USA
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6
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Turvey MW, Gabriel KN, Lee W, Taulbee JJ, Kim JK, Chen S, Lau CJ, Kattan RE, Pham JT, Majumdar S, Garcia D, Weiss GA, Collins PG. Single-molecule Taq DNA polymerase dynamics. SCIENCE ADVANCES 2022; 8:eabl3522. [PMID: 35275726 PMCID: PMC8916733 DOI: 10.1126/sciadv.abl3522] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
Taq DNA polymerase functions at elevated temperatures with fast conformational dynamics-regimes previously inaccessible to mechanistic, single-molecule studies. Here, single-walled carbon nanotube transistors recorded the motions of Taq molecules processing matched or mismatched template-deoxynucleotide triphosphate pairs from 22° to 85°C. By using four enzyme orientations, the whole-enzyme closures of nucleotide incorporations were distinguished from more rapid, 20-μs closures of Taq's fingers domain testing complementarity and orientation. On average, one transient closure was observed for every nucleotide binding event; even complementary substrate pairs averaged five transient closures between each catalytic incorporation at 72°C. The rate and duration of the transient closures and the catalytic events had almost no temperature dependence, leaving all of Taq's temperature sensitivity to its rate-determining open state.
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Affiliation(s)
- Mackenzie W. Turvey
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697-4575, USA
| | - Kristin N. Gabriel
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900, USA
| | - Wonbae Lee
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697-4575, USA
| | - Jeffrey J. Taulbee
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697-4575, USA
| | - Joshua K. Kim
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA
| | - Silu Chen
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA
| | - Calvin J. Lau
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697-4575, USA
| | - Rebecca E. Kattan
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900, USA
| | - Jenifer T. Pham
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA
| | - Sudipta Majumdar
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA
| | | | - Gregory A. Weiss
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA 92697-3900, USA
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA 92697-3958, USA
| | - Philip G. Collins
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697-4575, USA
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7
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Côté S, Bouilly D, Mousseau N. The molecular origin of the electrostatic gating of single-molecule field-effect biosensors investigated by molecular dynamics simulations. Phys Chem Chem Phys 2022; 24:4174-4186. [PMID: 35113103 DOI: 10.1039/d1cp04626h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Field-effect biosensors (bioFETs) offer a novel way to measure the kinetics of biomolecular events such as protein function and DNA hybridization at the single-molecule level on a wide range of time scales. These devices generate an electrical current whose fluctuations are correlated to the kinetics of the biomolecule under study. BioFETs are indeed highly sensitive to changes in the electrostatic potential (ESP) generated by the biomolecule. Here, using all-atom solvent explicit molecular dynamics simulations, we further investigate the molecular origin of the variation of this ESP for two prototypical cases of proteins or nucleic acids attached to a carbon nanotube bioFET: the function of the lysozyme protein and the hybridization of a 10-nt DNA sequence, as previously done experimentally. Our results show that the ESP changes significantly on the surface of the carbon nanotube as the state of these two biomolecules changes. More precisely, the ESP distributions calculated for these molecular states explain well the magnitude of the conductance fluctuations measured experimentally. The dependence of the ESP with salt concentration is found to agree with the reduced conductance fluctuations observed experimentally for the lysozyme, but to differ for the case of DNA, suggesting that other mechanisms might be at play in this case. Furthermore, we show that the carbon nanotube does not impact significantly the structural stability of the lysozyme, corroborating that the kinetic rates measured using bioFETs are similar to those measured by other techniques. For DNA, we find that the structural ensemble of the single-stranded DNA is significantly impacted by the presence of the nanotube, which, combined with the ESP analysis, suggests a stronger DNA-device interplay. Overall, our simulations strengthen the comprehension of the inner working of field-effect biosensors used for single-molecule kinetics measurements on proteins and nucleic acids.
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Affiliation(s)
- Sébastien Côté
- Département de Physique, Faculté des Arts et des Sciences, Université de Montréal, Montréal, Canada. .,Département de Physique, Cégep de Saint-Jérôme, Saint-Jérôme, Canada
| | - Delphine Bouilly
- Département de Physique, Faculté des Arts et des Sciences, Université de Montréal, Montréal, Canada. .,Institut de recherche en immunologie et cancérologie (IRIC), Université de Montréal, Montréal, Canada.
| | - Normand Mousseau
- Département de Physique, Faculté des Arts et des Sciences, Université de Montréal, Montréal, Canada.
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8
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Woo SO, Oh M, Alhalhooly L, Farmakes J, Rajapakse AJ, Yang Z, Collins PG, Choi Y. Different Single-Enzyme Conformational Dynamics upon Binding Hydrolyzable or Nonhydrolyzable Ligands. J Phys Chem B 2021; 125:5750-5756. [PMID: 34038124 DOI: 10.1021/acs.jpcb.1c01589] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Single-molecule measurements of protein dynamics help unveil the complex conformational changes and transitions that occur during ligand binding and catalytic processes. Using high-resolution single-molecule nanocircuit techniques, we have investigated differences in the conformational dynamics and transitions of lysozyme interacting with three ligands: peptidoglycan substrate, substrate-based chitin analogue, and indole derivative inhibitors. While processing peptidoglycan, lysozyme followed one of the two mechanistic pathways for the hydrolysis of the glycosidic bonds: a concerted mechanism inducing direct conformational changes from open to fully closed conformations or a nonconcerted mechanism involving transient pauses in intermediate conformations between the open and closed conformations. In the presence of either chitin or an indole inhibitor, lysozyme was unable to access the fully closed conformation where catalysis occurs. Instead, lysozymes' conformational closures terminated at slightly closed, "excited" conformations that were approximately one-quarter of the full hinge-bending range. With the indole inhibitor, lysozyme reached this excited conformation in a single step without any evidence of rate-liming intermediates, but the same conformational motions with chitin involved three hidden, intermediate processes and features similar to the nonconcerted peptidoglycan mechanism. The similarities suggest that these hidden processes involve attempts to accommodate imperfectly aligned polysaccharides in the active site. The results provide a detailed glimpse of the enzyme-ligand interplay at the crux of molecular recognition, enzyme specificity, and catalysis.
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Affiliation(s)
- Sung Oh Woo
- Department of Physics, North Dakota State University, Fargo, North Dakota 5810, United States
| | - Myungkeun Oh
- Materials and Nanotechnology Program, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Lina Alhalhooly
- Department of Physics, North Dakota State University, Fargo, North Dakota 5810, United States
| | - Jasmin Farmakes
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Arith J Rajapakse
- Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
| | - Zhongyu Yang
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Philip G Collins
- Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
| | - Yongki Choi
- Department of Physics, North Dakota State University, Fargo, North Dakota 5810, United States.,Materials and Nanotechnology Program, North Dakota State University, Fargo, North Dakota 58108, United States
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9
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Resolving dynamics and function of transient states in single enzyme molecules. Nat Commun 2020; 11:1231. [PMID: 32144241 PMCID: PMC7060211 DOI: 10.1038/s41467-020-14886-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 02/08/2020] [Indexed: 11/23/2022] Open
Abstract
We use a hybrid fluorescence spectroscopic toolkit to monitor T4 Lysozyme (T4L) in action by unraveling the kinetic and dynamic interplay of the conformational states. In particular, by combining single-molecule and ensemble multiparameter fluorescence detection, EPR spectroscopy, mutagenesis, and FRET-positioning and screening, and other biochemical and biophysical tools, we characterize three short-lived conformational states over the ns-ms timescale. The use of 33 FRET-derived distance sets, to screen available T4L structures, reveal that T4L in solution mainly adopts the known open and closed states in exchange at 4 µs. A newly found minor state, undisclosed by, at present, more than 500 crystal structures of T4L and sampled at 230 µs, may be actively involved in the product release step in catalysis. The presented fluorescence spectroscopic toolkit will likely accelerate the development of dynamic structural biology by identifying transient conformational states that are highly abundant in biology and critical in enzymatic reactions. T4 Lysozyme (T4L) is a model protein whose structure is extensively studied. Here the authors combine single-molecule and ensemble FRET measurements, FRET-positioning and screening and EPR spectroscopy to study the structural dynamics of T4L and describe its conformational landscape during the catalytic cycle by an extended Michaelis–Menten mechanism and identify an excited conformational state of the enzyme.
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10
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Feher VA, Schiffer JM, Mermelstein DJ, Mih N, Pierce LCT, McCammon JA, Amaro RE. Mechanisms for Benzene Dissociation through the Excited State of T4 Lysozyme L99A Mutant. Biophys J 2019; 116:205-214. [PMID: 30606449 PMCID: PMC6349996 DOI: 10.1016/j.bpj.2018.09.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 06/23/2018] [Accepted: 09/27/2018] [Indexed: 12/23/2022] Open
Abstract
The atomic-level mechanisms that coordinate ligand release from protein pockets are only known for a handful of proteins. Here, we report results from accelerated molecular dynamics simulations for benzene dissociation from the buried cavity of the T4 lysozyme Leu99Ala mutant (L99A). In these simulations, benzene is released through a previously characterized, sparsely populated room-temperature excited state of the mutant, explaining the coincidence for experimentally measured benzene off rate and apo protein slow-timescale NMR relaxation rates between ground and excited states. The path observed for benzene egress is a multistep ligand migration from the buried cavity to ultimate release through an opening between the F/G-, H-, and I-helices and requires a number of cooperative multiresidue and secondary-structure rearrangements within the C-terminal domain of L99A. These rearrangements are identical to those observed along the ground state to excited state transitions characterized by molecular dynamic simulations run on the Anton supercomputer. Analyses of the molecular properties of the residues lining the egress path suggest that protein surface electrostatic potential may play a role in the release mechanism. Simulations of wild-type T4 lysozyme also reveal that benzene-egress-associated dynamics in the L99A mutant are potentially exaggerations of the substrate-processivity-related dynamics of the wild type.
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Affiliation(s)
| | | | - Daniel J Mermelstein
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California
| | - Nathan Mih
- Department of Bioinformatics and Systems Biology, University of California San Diego, La Jolla, California
| | | | - J Andrew McCammon
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California
| | - Rommie E Amaro
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California.
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11
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12
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You S, Froberg J, Yu J, Haldar M, Sedigh A, Mallik S, Srivastava DK, Choi Y. Real-time monitoring of conformational transitions of single-molecule histone deacetylase 8 with nanocircuits. Chem Commun (Camb) 2018; 53:3307-3310. [PMID: 28261707 DOI: 10.1039/c6cc09949a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using single-molecule approaches, we directly observed the dynamic interaction between HDAC8 and various ligands as well as conformational interconversions during the catalytic reaction. Statistical analysis identified key kinetic parameters, demonstrating that the enzymatic activity is highly sensitive to both minor variations in the ligand structures and small synthetic molecules.
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Affiliation(s)
- Seungyong You
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108, USA.
| | - James Froberg
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108, USA.
| | - Junru Yu
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, USA
| | - Manas Haldar
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota 58108, USA
| | - Abbas Sedigh
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, USA
| | - Sanku Mallik
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota 58108, USA
| | - D K Srivastava
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, USA
| | - Yongki Choi
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108, USA.
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13
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Archer JJ, Karki S, Shi F, Sistani H, Levis RJ. Quantification of Protein-Ligand Interactions by Laser Electrospray Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1484-1492. [PMID: 29654537 DOI: 10.1007/s13361-018-1935-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 03/01/2018] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
Laser electrospray mass spectrometry (LEMS) measurement of the dissociation constant (Kd) for hen egg white lysozyme (HEWL) and N,N',N″-triacetylchitotriose (NAG3) revealed an apparent Kd value of 313.2 ± 25.9 μM for the ligand titration method. Similar measurements for N,N',N″,N″'-tetraacetylchitotetraose (NAG4) revealed an apparent Kd of 249.3 ± 13.6 μM. An electrospray ionization mass spectrometry (ESI-MS) experiment determined a Kd value of 9.8 ± 0.6 μM. In a second LEMS approach, a calibrated measurement was used to determine a Kd value of 6.8 ± 1.5 μM for NAG3. The capture efficiency of LEMS was measured to be 3.6 ± 1.8% and is defined as the fraction of LEMS sample detected after merging with the ESI plume. When the dilution is factored into the ligand titration measurement, the adjusted Kd value was 11.3 μM for NAG3 and 9.0 μM for NAG4. The calibration method for measuring Kd developed in this study can be applied to solutions containing unknown analyte concentrations. Graphical Abstract.
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Affiliation(s)
- Jieutonne J Archer
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Santosh Karki
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Fengjian Shi
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Habiballah Sistani
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA
| | - Robert J Levis
- Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, PA, 19122, USA.
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14
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Tian B, Xu S, Rogers JA, Cestellos-Blanco S, Yang P, Carvalho-de-Souza JL, Bezanilla F, Liu J, Bao Z, Hjort M, Cao Y, Melosh N, Lanzani G, Benfenati F, Galli G, Gygi F, Kautz R, Gorodetsky AA, Kim SS, Lu TK, Anikeeva P, Cifra M, Krivosudský O, Havelka D, Jiang Y. Roadmap on semiconductor-cell biointerfaces. Phys Biol 2018; 15:031002. [PMID: 29205173 PMCID: PMC6599646 DOI: 10.1088/1478-3975/aa9f34] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This roadmap outlines the role semiconductor-based materials play in understanding the complex biophysical dynamics at multiple length scales, as well as the design and implementation of next-generation electronic, optoelectronic, and mechanical devices for biointerfaces. The roadmap emphasizes the advantages of semiconductor building blocks in interfacing, monitoring, and manipulating the activity of biological components, and discusses the possibility of using active semiconductor-cell interfaces for discovering new signaling processes in the biological world.
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Affiliation(s)
- Bozhi Tian
- Department of Chemistry, University of Chicago, Chicago, IL 60637, United States of America
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15
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Mechanically switching single-molecule fluorescence of GFP by unfolding and refolding. Proc Natl Acad Sci U S A 2017; 114:11052-11056. [PMID: 29073015 DOI: 10.1073/pnas.1704937114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Green fluorescent protein (GFP) variants are widely used as genetically encoded fluorescent fusion tags, and there is an increasing interest in engineering their structure to develop in vivo optical sensors, such as for optogenetics and force transduction. Ensemble experiments have shown that the fluorescence of GFP is quenched upon denaturation. Here we study the dependence of fluorescence on protein structure by driving single molecules of GFP into different conformational states with optical tweezers and simultaneously probing the chromophore with fluorescence. Our results show that fluorescence is lost during the earliest events in unfolding, 3.5 ms before secondary structure is disrupted. No fluorescence is observed from the unfolding intermediates or the ensemble of compact and extended states populated during refolding. We further demonstrate that GFP can be mechanically switched between emissive and dark states. These data definitively establish that complete structural integrity is necessary to observe single-molecule fluorescence of GFP.
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16
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Lu M, Lu HP. Revealing Multiple Pathways in T4 Lysozyme Substep Conformational Motions by Single-Molecule Enzymology and Modeling. J Phys Chem B 2017; 121:5017-5024. [DOI: 10.1021/acs.jpcb.7b03039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Maolin Lu
- Department of Chemistry and
Center for Photochemical Sciences, Bowling Green State University, Bowling
Green, Ohio 43403, United States
| | - H. Peter Lu
- Department of Chemistry and
Center for Photochemical Sciences, Bowling Green State University, Bowling
Green, Ohio 43403, United States
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17
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Gül OT, Pugliese KM, Choi Y, Sims PC, Pan D, Rajapakse AJ, Weiss GA, Collins PG. Single Molecule Bioelectronics and Their Application to Amplification-Free Measurement of DNA Lengths. BIOSENSORS-BASEL 2016; 6:bios6030029. [PMID: 27348011 PMCID: PMC5039648 DOI: 10.3390/bios6030029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/08/2016] [Accepted: 06/15/2016] [Indexed: 01/17/2023]
Abstract
As biosensing devices shrink smaller and smaller, they approach a scale in which single molecule electronic sensing becomes possible. Here, we review the operation of single-enzyme transistors made using single-walled carbon nanotubes. These novel hybrid devices transduce the motions and catalytic activity of a single protein into an electronic signal for real-time monitoring of the protein’s activity. Analysis of these electronic signals reveals new insights into enzyme function and proves the electronic technique to be complementary to other single-molecule methods based on fluorescence. As one example of the nanocircuit technique, we have studied the Klenow Fragment (KF) of DNA polymerase I as it catalytically processes single-stranded DNA templates. The fidelity of DNA polymerases makes them a key component in many DNA sequencing techniques, and here we demonstrate that KF nanocircuits readily resolve DNA polymerization with single-base sensitivity. Consequently, template lengths can be directly counted from electronic recordings of KF’s base-by-base activity. After measuring as few as 20 copies, the template length can be determined with <1 base pair resolution, and different template lengths can be identified and enumerated in solutions containing template mixtures.
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Affiliation(s)
- O Tolga Gül
- Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697, USA
- Department of Physics, Polatlı Faculty of Science and Arts, Gazi University, Polatlı 06900, Turkey
| | - Kaitlin M Pugliese
- Department of Chemistry, University of California at Irvine, Irvine, CA 92697, USA
| | - Yongki Choi
- Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697, USA
- Department of Physics, North Dakota State University, Fargo, ND 58108, USA
| | - Patrick C Sims
- Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697, USA
| | - Deng Pan
- Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697, USA
| | - Arith J Rajapakse
- Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697, USA
| | - Gregory A Weiss
- Department of Chemistry, University of California at Irvine, Irvine, CA 92697, USA.
- Department of Molecular Biology and Biochemistry, University of California at Irvine, Irvine, CA 92697, USA.
| | - Philip G Collins
- Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697, USA.
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