1
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Birch-Price Z, Hardy FJ, Lister TM, Kohn AR, Green AP. Noncanonical Amino Acids in Biocatalysis. Chem Rev 2024; 124:8740-8786. [PMID: 38959423 PMCID: PMC11273360 DOI: 10.1021/acs.chemrev.4c00120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 07/05/2024]
Abstract
In recent years, powerful genetic code reprogramming methods have emerged that allow new functional components to be embedded into proteins as noncanonical amino acid (ncAA) side chains. In this review, we will illustrate how the availability of an expanded set of amino acid building blocks has opened a wealth of new opportunities in enzymology and biocatalysis research. Genetic code reprogramming has provided new insights into enzyme mechanisms by allowing introduction of new spectroscopic probes and the targeted replacement of individual atoms or functional groups. NcAAs have also been used to develop engineered biocatalysts with improved activity, selectivity, and stability, as well as enzymes with artificial regulatory elements that are responsive to external stimuli. Perhaps most ambitiously, the combination of genetic code reprogramming and laboratory evolution has given rise to new classes of enzymes that use ncAAs as key catalytic elements. With the framework for developing ncAA-containing biocatalysts now firmly established, we are optimistic that genetic code reprogramming will become a progressively more powerful tool in the armory of enzyme designers and engineers in the coming years.
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Affiliation(s)
| | | | | | | | - Anthony P. Green
- Manchester Institute of Biotechnology,
School of Chemistry, University of Manchester, Manchester M1 7DN, U.K.
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2
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Peng HC, Mohan S, Huq MT, Bull JA, Michaud T, Piercy TC, Hilber S, Wettasinghe AP, Slinker JD, Kreutz C, Stelling AL. Isotope-Edited Variable Temperature Infrared Spectroscopy for Measuring Transition Temperatures of Single A-T Watson-Crick Base Pairs in DNA Duplexes. Anal Chem 2024; 96:8868-8874. [PMID: 38775341 DOI: 10.1021/acs.analchem.4c00056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Experimental methods to determine transition temperatures for individual base pair melting events in DNA duplexes are lacking despite intense interest in these thermodynamic parameters. Here, we determine the dimensions of the thymine (T) C2═O stretching vibration when it is within the DNA duplex via isotopic substitutions at other atomic positions in the structure. First, we determined that this stretching state was localized enough to specific atoms in the molecule to make submolecular scale measurements of local structure and stability in high molecular weight complexes. Next, we develop a new isotope-edited variable temperature infrared method to measure melting transitions at various locations in a DNA structure. As an initial test of this "sub-molecular scale thermometer", we applied our T13C2 difference infrared signal to measure location-dependent melting temperatures (TmL) in a DNA duplex via variable temperature attenuated total reflectance Fourier transform infrared (VT-ATR-FTIR) spectroscopy. We report that the TmL of a single Watson-Crick A-T base pair near the end of an A-T rich sequence (poly T) is ∼34.9 ± 0.7°C. This is slightly lower than the TmL of a single base pair near the middle position of the poly T sequence (TmL ∼35.6±0.2°C). In addition, we also report that the TmL of a single Watson-Crick A-T base pair near the end of a 50% G-C sequence (12-mer) is ∼52.5 ± 0.3°C, which is slightly lower than the global melting Tm of the 12-mer sequence (TmL ∼54.0±0.9°C). Our results provide direct physical evidence for end fraying in DNA sequences with our novel spectroscopic methods.
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Affiliation(s)
- Hao-Che Peng
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Shrijaa Mohan
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Muhammad T Huq
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Julie A Bull
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Troy Michaud
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Turner C Piercy
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Stefan Hilber
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck 6020, Austria
| | - Ashan P Wettasinghe
- Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Jason D Slinker
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
- Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Christoph Kreutz
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck 6020, Austria
| | - Allison L Stelling
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
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3
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Hunt NT. Biomolecular infrared spectroscopy: making time for dynamics. Chem Sci 2024; 15:414-430. [PMID: 38179520 PMCID: PMC10763549 DOI: 10.1039/d3sc05223k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/24/2023] [Indexed: 01/06/2024] Open
Abstract
Time resolved infrared spectroscopy of biological molecules has provided a wealth of information relating to structural dynamics, conformational changes, solvation and intermolecular interactions. Challenges still exist however arising from the wide range of timescales over which biological processes occur, stretching from picoseconds to minutes or hours. Experimental methods are often limited by vibrational lifetimes of probe groups, which are typically on the order of picoseconds, while measuring an evolving system continuously over some 18 orders of magnitude in time presents a raft of technological hurdles. In this Perspective, a series of recent advances which allow biological molecules and processes to be studied over an increasing range of timescales, while maintaining ultrafast time resolution, will be reviewed, showing that the potential for real-time observation of biomolecular function draws ever closer, while offering a new set of challenges to be overcome.
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Affiliation(s)
- Neil T Hunt
- Department of Chemistry and York Biomedical Research Institute, University of York Heslington York YO10 5DD UK
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4
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Hassanuddin NA, Normaya E, Ismail H, Iqbal A, Piah MBM, Abd Hamid S, Ahmad MN. Methyl 4-pyridyl ketone thiosemicarbazone (4-PT) as an effective and safe inhibitor of mushroom tyrosinase and antibrowning agent. Int J Biol Macromol 2024; 255:128229. [PMID: 37981274 DOI: 10.1016/j.ijbiomac.2023.128229] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 11/12/2023] [Accepted: 11/16/2023] [Indexed: 11/21/2023]
Abstract
Enzymatic browning is of concern as it can affect food safety and quality. In this study, an effective and safe tyrosinase inhibitor and anti-browning agent, methyl 4-pyridyl ketone thiosemicarbazone (4-PT), was synthesised and characterised using Fourier-transform infrared (FTIR) spectroscopy, CHNS elemental analysis, and proton (1H) and carbon-13 (13C) nuclear magnetic resonance (NMR) spectroscopy. The vibrational frequencies of 4-PT were studied theoretically using vibrational energy distribution analysis (VEDA). Density functional theory (DFT) was applied to elucidate its chemical properties, including the Mulliken atomic charges, molecular electrostatic potential (MEP), quantum theory of atoms in molecules (QTAIM) and reduced density gradient non-covalent interactions (RDG-NCIs). Moreover, 4-PT was compared with kojic acid in terms of its effectiveness as a tyrosinase inhibitor and anti-browning agent. The toxicity and physicochemical properties of 4-PT were predicted via ADME evaluation, which proved that 4-PT is safer than kojic acid. Experimentally, 4-PT (IC50 = 5.82 μM, browning index (10 days) = 0.292 ± 0.002) was proven to be an effective tyrosinase inhibitor and anti-browning agent compared to kojic acid (IC50 = 128.17 μM, browning index (10 days) = 0.332 ± 0.002). Furthermore, kinetic analyses indicated that the type of tyrosinase inhibition is a mixed inhibition, with Km and Vmax values of 0.85 mM and 2.78 E-09 μM/s, respectively. Finally, the mechanism of 4-PT for tyrosinase inhibition was proven by 1D, second derivative and 2D IR spectroscopy, molecular docking and molecular dynamic simulation approaches.
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Affiliation(s)
- Nur Amanina Hassanuddin
- Experimental and Theoretical Research Lab (ETRL), Department of Chemistry, Kulliyyah of Science, IIUM, Kuantan, Pahang, Malaysia
| | - Erna Normaya
- Experimental and Theoretical Research Lab (ETRL), Department of Chemistry, Kulliyyah of Science, IIUM, Kuantan, Pahang, Malaysia; Sustainable Nanotechnology and Computational Modelling (SuNCoM) Research Group, Kulliyyah of Science, International Islamic University Malaysia, 25200 Kuantan, Pahang, Malaysia
| | - Hakimah Ismail
- Experimental and Theoretical Research Lab (ETRL), Department of Chemistry, Kulliyyah of Science, IIUM, Kuantan, Pahang, Malaysia
| | - Anwar Iqbal
- School of Chemical Science, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Mohd Bijarimi Mat Piah
- Faculty of Chemical & Natural Resources Engineering, Universiti Malaysia Pahang, Kuantan, Malaysia
| | - Shafida Abd Hamid
- Department of Chemistry, Kulliyyah of Science, IIUM, Kuantan, Pahang, Malaysia
| | - Mohammad Norazmi Ahmad
- Experimental and Theoretical Research Lab (ETRL), Department of Chemistry, Kulliyyah of Science, IIUM, Kuantan, Pahang, Malaysia; Sustainable Nanotechnology and Computational Modelling (SuNCoM) Research Group, Kulliyyah of Science, International Islamic University Malaysia, 25200 Kuantan, Pahang, Malaysia.
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5
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Maia RN, Mitra S, Baiz CR. Extracting accurate infrared lineshapes from weak vibrational probes at low concentrations. MethodsX 2023; 11:102309. [PMID: 37577166 PMCID: PMC10416016 DOI: 10.1016/j.mex.2023.102309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/31/2023] [Indexed: 08/15/2023] Open
Abstract
Fourier-transform infrared (FTIR) spectroscopy using vibrational probes is an ideal tool to detect changes in structure and local environments within biological molecules. However, challenges arise when dealing with weak infrared probes, such as thiocyanates, due to their inherent low signal strengths and overlap with solvent bands. In this protocol we demonstrate:•A streamlined approach for the precise extraction of weak infrared absorption lineshapes from a strong solvent background.•A protocol combining a spectral filter, background modeling, and subtraction.•Our methodology successfully extracts the CN stretching mode peak from methyl thiocyanate at remarkably low concentrations (0.25 mM) in water, previously a challenge for FTIR spectroscopy.This approach offers valuable insights and tools for more accurate FTIR measurements using weak vibrational probes. This enhanced precision can potentially enable new approaches to enhance our understanding of protein structure and dynamics in solution.
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Affiliation(s)
- Raiza N.A. Maia
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712-1224, USA
| | - Sunayana Mitra
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712-1224, USA
| | - Carlos R. Baiz
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712-1224, USA
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6
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Perera SM, Aikawa T, Shaner SE, Moran SD, Wang L. Effects of the Intramolecular Group and Solvent on Vibrational Coupling Modes and Strengths of Fermi Resonances in Aryl Azides: A DFT Study of 4-Azidotoluene and 4-Azido- N-phenylmaleimide. J Phys Chem A 2023; 127:8911-8921. [PMID: 37819373 DOI: 10.1021/acs.jpca.3c06312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
The high transition dipole strength of the azide asymmetric stretch makes aryl azides good candidates as vibrational probes (VPs). However, aryl azides have complex absorption profiles due to Fermi resonances (FRs). Understanding the origin and the vibrational modes involved in FRs of aryl azides is critically important toward developing them as VPs for studies of protein structures and structural changes in response to their surroundings. As such, we studied vibrational couplings in 4-azidotoluene and 4-azido-N-phenylmaleimide in two solvents, N,N-dimethylacetamide and tetrahydrofuran, to explore the origin and the effects of intramolecular group and solvent on the FRs of aryl azides using density functional theory (DFT) calculations with the B3LYP functional and seven basis sets, 6-31G(d,p), 6-31+G(d,p), 6-31++G(d,p), 6-311G(d,p), 6-311+G(d,p), 6-311++G(d,p), and 6-311++G(df,pd). Two combination bands consisting of the azide symmetric stretch and another mode form strong FRs with the azide asymmetric stretch for both molecules. The FR profile was altered by replacing the methyl group with maleimide. Solvents change the relative peak position and intensity more significantly for 4-azido-N-phenylmaleimide, which makes it a more sensitive VP. Furthermore, the DFT results indicate that a comparison among the results from different basis sets can be used as a means to predict more reliable vibrational spectra.
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Affiliation(s)
- Sathya M Perera
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Tenyu Aikawa
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Sarah E Shaner
- Department of Chemistry and Physics, Southeast Missouri State University, Cape Girardeau, Missouri 63701, United States
| | - Sean D Moran
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Lichang Wang
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901, United States
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7
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Al-Mualem ZA, Chen X, Shirley JC, Xu C, Baiz CR. BoxCARS 2D IR spectroscopy with pulse shaping. OPTICS EXPRESS 2023; 31:2700-2709. [PMID: 36785278 PMCID: PMC10018786 DOI: 10.1364/oe.471984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/31/2022] [Accepted: 09/15/2022] [Indexed: 06/18/2023]
Abstract
BoxCARS and pump-probe geometries are common implementations of two-dimensional infrared (2D IR) spectroscopy. BoxCARS is background-free, generally offering greater signal-to-noise ratio, which enables measuring weak vibrational echo signals. Pulse shapers have been implemented in the pump-probe geometry to accelerate data collection and suppress scatter and other unwanted signals by precise control of the pump-pulse delay and carrier phase. Here, we introduce a 2D-IR optical setup in the BoxCARS geometry that implements a pulse shaper for rapid acquisition of background-free 2D IR spectra. We show a signal-to-noise improvement using this new fast-scan BoxCARS setup versus the pump-probe geometry within the same configuration.
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Affiliation(s)
- Ziareena A. Al-Mualem
- Department of Chemistry, University of Texas at Austin, 105 E 24th Street, Austin, TX 78712, USA
- Authors contributed equally
| | - Xiaobing Chen
- Department of Chemistry, University of Texas at Austin, 105 E 24th Street, Austin, TX 78712, USA
- Authors contributed equally
| | - Joseph C. Shirley
- Department of Chemistry, University of Texas at Austin, 105 E 24th Street, Austin, TX 78712, USA
| | - Cong Xu
- Department of Chemistry, University of Texas at Austin, 105 E 24th Street, Austin, TX 78712, USA
| | - Carlos R. Baiz
- Department of Chemistry, University of Texas at Austin, 105 E 24th Street, Austin, TX 78712, USA
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8
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Structural Analysis and Classification of Low-Molecular-Weight Hyaluronic Acid by Near-Infrared Spectroscopy: A Comparison between Traditional Machine Learning and Deep Learning. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020809. [PMID: 36677867 PMCID: PMC9862636 DOI: 10.3390/molecules28020809] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/06/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
Confusing low-molecular-weight hyaluronic acid (LMWHA) from acid degradation and enzymatic hydrolysis (named LMWHA-A and LMWHA-E, respectively) will lead to health hazards and commercial risks. The purpose of this work is to analyze the structural differences between LMWHA-A and LMWHA-E, and then achieve a fast and accurate classification based on near-infrared (NIR) spectroscopy and machine learning. First, we combined nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, two-dimensional correlated NIR spectroscopy (2DCOS), and aquaphotomics to analyze the structural differences between LMWHA-A and LMWHA-E. Second, we compared the dimensionality reduction methods including principal component analysis (PCA), kernel PCA (KPCA), and t-distributed stochastic neighbor embedding (t-SNE). Finally, the differences in classification effect of traditional machine learning methods including partial least squares-discriminant analysis (PLS-DA), support vector classification (SVC), and random forest (RF) as well as deep learning methods including one-dimensional convolutional neural network (1D-CNN) and long short-term memory (LSTM) were compared. The results showed that genetic algorithm (GA)-SVC and RF were the best performers in traditional machine learning, but their highest accuracy in the test dataset was 90%, while the accuracy of 1D-CNN and LSTM models in the training dataset and test dataset classification was 100%. The results of this study show that compared with traditional machine learning, the deep learning models were better for the classification of LMWHA-A and LMWHA-E. Our research provides a new methodological reference for the rapid and accurate classification of biological macromolecules.
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9
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Dong T, Yu P, Zhao J, Wang J. Probing the local structure and dynamics of nucleotides using vibrationally enhanced alkynyl stretching. Phys Chem Chem Phys 2022; 24:29988-29998. [PMID: 36472165 DOI: 10.1039/d2cp03920f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Monitoring the site-specific local structure and dynamics of polynucleotides and DNA is important for understanding their biological functions. However, structurally characterizing these biomolecules with high time resolution has been known to be experimentally challenging. In this work, several 5-silylethynyl-2'-deoxynucleosides and 5-substituted phenylethynyl-2'-deoxynucleosides on the basis of deoxycytidine (dC) and deoxythymidine (dT) were synthesized, in which the alkynyl group shows intensified CC stretching vibration with infrared transition dipole moment magnitude close to that of typical CO stretching, and exhibits structural sensitivities in both vibrational frequency and spectral width. In particular, 5-trimethylsilylethynyl-2'-dC (TMSEdC, molecule 1a) was examined in detail using femtosecond nonlinear IR spectroscopy. The solvent dependent CC stretching frequency of 1a can be reasonably interpreted mainly as the hydrogen-bonding effect between the solvent and cytosine base ring structure. Transient 2D IR and pump-probe IR measurements of 1a carried out comparatively in two aprotic solvents (DMSO and THF) and one protic solvent (MeOH) further reveal solvent dependent ultrafast vibrational properties, including diagonal anharmonicity, spectral diffusion, vibrational relaxation and anisotropy dynamics. These observed sensitivities are rooted in an extended π-conjugation of the base ring structure in which the CC group is actively involved. Our results show that the intensified CC stretching vibration can potentially provide a site-specific IR probe for monitoring the equilibrium and ultrafast structural dynamics of polynucleotides.
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Affiliation(s)
- Tiantian Dong
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Pengyun Yu
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Juan Zhao
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jianping Wang
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China. .,University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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10
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Kraka E, Quintano M, La Force HW, Antonio JJ, Freindorf M. The Local Vibrational Mode Theory and Its Place in the Vibrational Spectroscopy Arena. J Phys Chem A 2022; 126:8781-8798. [DOI: 10.1021/acs.jpca.2c05962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elfi Kraka
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Mateus Quintano
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Hunter W. La Force
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Juliana J. Antonio
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
| | - Marek Freindorf
- Computational and Theoretical Chemistry Group (CATCO), Department of Chemistry, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas75275-0314, United States
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11
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An Y, Sedinkin SL, Venditti V. Solution NMR methods for structural and thermodynamic investigation of nanoparticle adsorption equilibria. NANOSCALE ADVANCES 2022; 4:2583-2607. [PMID: 35769933 PMCID: PMC9195484 DOI: 10.1039/d2na00099g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Accepted: 05/07/2022] [Indexed: 05/09/2023]
Abstract
Characterization of dynamic processes occurring at the nanoparticle (NP) surface is crucial for developing new and more efficient NP catalysts and materials. Thus, a vast amount of research has been dedicated to developing techniques to characterize sorption equilibria. Over recent years, solution NMR spectroscopy has emerged as a preferred tool for investigating ligand-NP interactions. Indeed, due to its ability to probe exchange dynamics over a wide range of timescales with atomic resolution, solution NMR can provide structural, kinetic, and thermodynamic information on sorption equilibria involving multiple adsorbed species and intermediate states. In this contribution, we review solution NMR methods for characterizing ligand-NP interactions, and provide examples of practical applications using these methods as standalone techniques. In addition, we illustrate how the integrated analysis of several NMR datasets was employed to elucidate the role played by support-substrate interactions in mediating the phenol hydrogenation reaction catalyzed by ceria-supported Pd nanoparticles.
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Affiliation(s)
- Yeongseo An
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Sergey L Sedinkin
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University Hach Hall, 2438 Pammel Drive Ames Iowa 50011 USA +1-515-294-7550 +1-515-294-1044
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University Ames Iowa 50011 USA
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12
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Intermolecular Vibration Energy Transfer Process in Two CL-20-Based Cocrystals Theoretically Revealed by Two-Dimensional Infrared Spectra. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27072153. [PMID: 35408551 PMCID: PMC9000797 DOI: 10.3390/molecules27072153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/21/2022] [Accepted: 03/25/2022] [Indexed: 11/17/2022]
Abstract
Inspired by the recent cocrystallization and theory of energetic materials, we theoretically investigated the intermolecular vibrational energy transfer process and the non-covalent intermolecular interactions between explosive compounds. The intermolecular interactions between 2,4,6-trinitrotoluene (TNT) and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and between 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) and CL-20 were studied using calculated two-dimensional infrared (2D IR) spectra and the independent gradient model based on the Hirshfeld partition (IGMH) method, respectively. Based on the comparison of the theoretical infrared spectra and optimized geometries with experimental results, the theoretical models can effectively reproduce the experimental geometries. By analyzing cross-peaks in the 2D IR spectra of TNT/CL-20, the intermolecular vibrational energy transfer process between TNT and CL-20 was calculated, and the conclusion was made that the vibrational energy transfer process between CL-20 and TNTII (TNTIII) is relatively slower than between CL-20 and TNTI. As the vibration energy transfer is the bridge of the intermolecular interactions, the weak intermolecular interactions were visualized using the IGMH method, and the results demonstrate that the intermolecular non-covalent interactions of TNT/CL-20 include van der Waals (vdW) interactions and hydrogen bonds, while the intermolecular non-covalent interactions of HMX/CL-20 are mainly comprised of vdW interactions. Further, we determined that the intermolecular interaction can stabilize the trigger bond in TNT/CL-20 and HMX/CL-20 based on Mayer bond order density, and stronger intermolecular interactions generally indicate lower impact sensitivity of energetic materials. We believe that the results obtained in this work are important for a better understanding of the cocrystal mechanism and its application in the field of energetic materials.
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13
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Garrett P, Baiz CR. Dynamic effect of polymers at the surfactant-water interface: an ultrafast study. SOFT MATTER 2022; 18:1793-1800. [PMID: 35170620 DOI: 10.1039/d1sm01651b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Interfaces play a role in controlling the rates and outcomes of chemical processes. Characterizing the interactions at heterogeneous interfaces is critical to developing a comprehensive model of the role of interfaces and confinement in modulating chemical reactions. Reverse micelles are an ideal model system for exploring the effect of encapsulated species on interfacial environments. Here, we use a combination of ultrafast two-dimensional infrared (2D IR) spectroscopy and molecular dynamics (MD) simulations to characterize the picosecond interfacial dynamics in reverse micelles (RMs) containing acrylamide monomers and polyacrylamide polymers within the aqueous phase. The ester carbonyl vibrations of the sorbitan monostearate surfactants are examined to extract interfacial hydrogen-bonding populations and dynamics. Hydrogen bond populations at the ester carbonyl positions remain unchanged with the inclusion of either polymer or monomer species. Hydrogen-bond dynamics are not altered with the addition of monomer but are slowed down twofold in the presence of encapsulated polyacrylamide polymer species as a result of polymer chains partially localizing to the interface. These findings imply that kinetics of reactions that occur at interfaces or in confined environments could be modulated by interfacial localization of the different components.
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Affiliation(s)
- Paul Garrett
- Department of Chemistry, The University of Texas at Austin, Austin, TX, USA.
| | - Carlos R Baiz
- Department of Chemistry, The University of Texas at Austin, Austin, TX, USA.
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14
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Price DA, Wedamulla P, Hill TD, Loth TM, Moran SD. The polarization dependence of 2D IR cross-peaks distinguishes parallel-stranded and antiparallel-stranded DNA G-quadruplexes. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120596. [PMID: 34801392 DOI: 10.1016/j.saa.2021.120596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/01/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
Guanine-rich nucleic acid sequences have a tendency to form four-stranded non-canonical motifs known as G-quadruplexes. These motifs may adopt a wide range of structures characterized by size, strand orientation, guanine base conformation, and fold topology. Using three K+-bound model systems, we show that vibrational coupling between guanine C6 = O and ring modes varies between parallel-stranded and antiparallel-stranded G-quadruplexes, and that such structures can be distinguished by comparison of the polarization dependences of cross-peaks in their two-dimensional infrared (2D IR) spectra. Combined with previously defined vibrational frequency trends, this analysis reveals key features of a 30-nucleotide unimolecular variant of the Bcl-2 proximal promoter that are consistent with its reported structure. This study shows that 2D IR spectroscopy is a convenient method for analyzing G-quadruplex structures that can be applied to complex sequences where traditional high-resolution methods are limited by solubility and disorder.
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Affiliation(s)
- David A Price
- School of Chemical and Biomolecular Sciences, Southern Illinois University Carbondale, 1245 Lincoln Drive MC 4409, Carbondale, IL 62901, United States
| | - Poornima Wedamulla
- School of Chemical and Biomolecular Sciences, Southern Illinois University Carbondale, 1245 Lincoln Drive MC 4409, Carbondale, IL 62901, United States
| | - Tayler D Hill
- School of Chemical and Biomolecular Sciences, Southern Illinois University Carbondale, 1245 Lincoln Drive MC 4409, Carbondale, IL 62901, United States
| | - Taylor M Loth
- School of Chemical and Biomolecular Sciences, Southern Illinois University Carbondale, 1245 Lincoln Drive MC 4409, Carbondale, IL 62901, United States
| | - Sean D Moran
- School of Chemical and Biomolecular Sciences, Southern Illinois University Carbondale, 1245 Lincoln Drive MC 4409, Carbondale, IL 62901, United States.
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15
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Abstract
Many of the proposed applications of metal-organic framework (MOF) materials may fail to materialize if the community does not fully address the difficult fundamental work needed to map out the 'time gap' in the literature - that is, the lack of investigation into the time-dependent behaviours of MOFs as opposed to equilibrium or steady-state properties. Although there are a range of excellent investigations into MOF dynamics and time-dependent phenomena, these works represent only a tiny fraction of the vast number of MOF studies. This Review provides an overview of current research into the temporal evolution of MOF structures and properties by analysing the time-resolved experimental techniques that can be used to monitor such behaviours. We focus on innovative techniques, while also discussing older methods often used in other chemical systems. Four areas are examined: MOF formation, guest motion, electron motion and framework motion. In each area, we highlight the disparity between the relatively small amount of (published) research on key time-dependent phenomena and the enormous scope for acquiring the wider and deeper understanding that is essential for the future of the field.
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16
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Kübel J, Westenhoff S, Maj M. Giving voice to the weak: Application of active noise reduction in transient infrared spectroscopy. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.139059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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17
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Thielges MC. Transparent window 2D IR spectroscopy of proteins. J Chem Phys 2021; 155:040903. [PMID: 34340394 PMCID: PMC8302233 DOI: 10.1063/5.0052628] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/21/2021] [Indexed: 02/01/2023] Open
Abstract
Proteins are complex, heterogeneous macromolecules that exist as ensembles of interconverting states on a complex energy landscape. A complete, molecular-level understanding of their function requires experimental tools to characterize them with high spatial and temporal precision. Infrared (IR) spectroscopy has an inherently fast time scale that can capture all states and their dynamics with, in principle, bond-specific spatial resolution. Two-dimensional (2D) IR methods that provide richer information are becoming more routine but remain challenging to apply to proteins. Spectral congestion typically prevents selective investigation of native vibrations; however, the problem can be overcome by site-specific introduction of amino acid side chains that have vibrational groups with frequencies in the "transparent window" of protein spectra. This Perspective provides an overview of the history and recent progress in the development of transparent window 2D IR of proteins.
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Affiliation(s)
- Megan C. Thielges
- Department of Chemistry, Indiana University, Bloomington,
Indiana 47405, USA
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18
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Tumbic GW, Hossan MY, Thielges MC. Protein Dynamics by Two-Dimensional Infrared Spectroscopy. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2021; 14:299-321. [PMID: 34314221 PMCID: PMC8713465 DOI: 10.1146/annurev-anchem-091520-091009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Proteins function as ensembles of interconverting structures. The motions span from picosecond bond rotations to millisecond and longer subunit displacements. Characterization of functional dynamics on all spatial and temporal scales remains challenging experimentally. Two-dimensional infrared spectroscopy (2D IR) is maturing as a powerful approach for investigating proteins and their dynamics. We outline the advantages of IR spectroscopy, describe 2D IR and the information it provides, and introduce vibrational groups for protein analysis. We highlight example studies that illustrate the power and versatility of 2D IR for characterizing protein dynamics and conclude with a brief discussion of the outlook for biomolecular 2D IR.
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Affiliation(s)
- Goran W Tumbic
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, USA;
| | - Md Yeathad Hossan
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, USA;
| | - Megan C Thielges
- Department of Chemistry, Indiana University, Bloomington, Indiana 47401, USA;
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19
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Watson MD, Lee JC. Coupling chemical biology and vibrational spectroscopy for studies of amyloids in vitro and in cells. Curr Opin Chem Biol 2021; 64:90-97. [PMID: 34186291 DOI: 10.1016/j.cbpa.2021.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/04/2021] [Accepted: 05/18/2021] [Indexed: 01/21/2023]
Abstract
Amyloid diseases are characterized by the aggregation of various proteins to form insoluble β-sheet-rich fibrils leading to cell death. Vibrational spectroscopies have emerged as attractive methods to study this process because of the rich structural information that can be extracted without large, perturbative probes. Importantly, specific vibrations such as the amide-I band directly report on secondary structure changes, which are key features of amyloid formation. Beyond intrinsic vibrations, the incorporation of unnatural vibrational probes can improve sensitivity for secondary structure determination (e.g. isotopic labeling), can provide residue-specific information of the surrounding polarity (e.g. unnatural amino acid), and are translatable into cellular studies. Here, we review the latest studies that have leveraged tools from chemical biology for the incorporation of novel vibrational probes into amyloidogenic proteins for both mechanistic and cellular studies.
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Affiliation(s)
- Matthew D Watson
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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20
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Procacci B, Rutherford SH, Greetham GM, Towrie M, Parker AW, Robinson CV, Howle CR, Hunt NT. Differentiation of bacterial spores via 2D-IR spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 249:119319. [PMID: 33360210 DOI: 10.1016/j.saa.2020.119319] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/26/2020] [Accepted: 12/05/2020] [Indexed: 06/12/2023]
Abstract
Ultrafast 2D-IR spectroscopy is a powerful tool for understanding the spectroscopy and dynamics of biological molecules in the solution phase. A number of recent studies have begun to explore the utility of the information-rich 2D-IR spectra for analytical applications. Here, we report the application of ultrafast 2D-IR spectroscopy for the detection and classification of bacterial spores. 2D-IR spectra of Bacillus atrophaeus and Bacillus thuringiensis spores as dry films on CaF2 windows were obtained. The sporulated nature of the bacteria was confirmed using 2D-IR diagonal and off-diagonal peaks arising from the calcium dipicolinate CaDP·3H2O biomarker for sporulation. Distinctive peaks, in the protein amide I region of the spectrum were used to differentiate the two types of spore. The identified marker modes demonstrate the potential for the use of 2D-IR methods as a direct means of spore classification. We discuss these new results in perspective with the current state of analytical 2D-IR measurements, showing that the potential exists to apply 2D-IR spectroscopy to detect the spores on surfaces and in suspensions as well as in dry films. The results demonstrate how applying 2D-IR screening methodologies to spores would enable the creation of a library of spectra for classification purposes.
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Affiliation(s)
- Barbara Procacci
- Department of Chemistry and York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, UK
| | - Samantha H Rutherford
- Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, UK
| | - Gregory M Greetham
- STFC Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | - Michael Towrie
- STFC Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | - Anthony W Parker
- STFC Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | - Camilla V Robinson
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
| | - Christopher R Howle
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
| | - Neil T Hunt
- Department of Chemistry and York Biomedical Research Institute, University of York, Heslington, York YO10 5DD, UK
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21
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Ramos S, Mammoser CC, Thibodeau KE, Thielges MC. Dynamics underlying hydroxylation selectivity of cytochrome P450cam. Biophys J 2021; 120:912-923. [PMID: 33545101 PMCID: PMC8008267 DOI: 10.1016/j.bpj.2021.01.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/18/2021] [Accepted: 01/27/2021] [Indexed: 10/22/2022] Open
Abstract
Structural heterogeneity and the dynamics of the complexes of enzymes with substrates can determine the selectivity of catalysis; however, fully characterizing how remains challenging as heterogeneity and dynamics can vary at the spatial level of an amino acid residue and involve rapid timescales. We demonstrate the nascent approach of site-specific two-dimensional infrared (IR) spectroscopy to investigate the archetypical cytochrome P450, P450cam, to better delineate the mechanism of the lower regioselectivity of hydroxylation of the substrate norcamphor in comparison to the native substrate camphor. Specific locations are targeted throughout the enzyme by selectively introducing cyano groups that have frequencies in a spectrally isolated region of the protein IR spectrum as local vibrational probes. Linear and two-dimensional IR spectroscopy were applied to measure the heterogeneity and dynamics at each probe and investigate how they differentiate camphor and norcamphor recognition. The IR data indicate that the norcamphor complex does not fully induce a large-scale conformational change to a closed state of the enzyme adopted in the camphor complex. Additionally, a probe directed at the bound substrate experiences rapidly interconverting states in the norcamphor complex that explain the hydroxylation product distribution. Altogether, the study reveals large- and small-scale structural heterogeneity and dynamics that could contribute to selectivity of a cytochrome P450 and illustrates the approach of site-selective IR spectroscopy to elucidate protein dynamics.
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Affiliation(s)
- Sashary Ramos
- Department of Chemistry, Indiana University, Bloomington, Indiana
| | | | | | - Megan C Thielges
- Department of Chemistry, Indiana University, Bloomington, Indiana.
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22
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Mukherjee P, Chandra Singh P. Experimental insight into enzyme catalysis and dynamics: A review on applications of state of art spectroscopic methods. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 122:33-62. [PMID: 32951815 DOI: 10.1016/bs.apcsb.2020.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enzymes are dynamic in nature and understanding their activity depends on exploring their overall structural fluctuation as well as transformation at the active site in free state as well as turnover conditions. In this chapter, the application of several different spectroscopy techniques viz. single molecule spectroscopy, ultrafast spectroscopy and Raman spectroscopy in the context of enzyme dynamics and catalysis are discussed. The importance of such studies are significant in the understanding of new discoveries of drugs, cure for some lethal diseases, gene modification as well as in industrial applications.
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Affiliation(s)
- Puspal Mukherjee
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, West Bengal, India
| | - Prashant Chandra Singh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, West Bengal, India
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23
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Linear and Non-Linear Middle Infrared Spectra of Penicillin G in the CO Stretching Mode Region. Symmetry (Basel) 2021. [DOI: 10.3390/sym13010106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this work we report the linear and non-linear IR spectral response characterization of the CO bonds of PenicillinG sodium salt in D2O and in DMSO−d6 solutions. In order to better characterize the spectral IR features in the CO stretching region, broadband middle infrared pump-probe spectra are recorded. The role of hydrogen bonds in determining the inhomogeneous broadening and in tuning anharmonicity of the different types of oscillators is exploited. Narrow band pump experiments, at the three central frequencies of β−lactam, amide and carboxylate CO stretching modes, identify the couplings between the different types of CO oscillators opening the possibility to gather structural dynamic information. Our results show that the strongest coupling is between the β−lactam and the carboxylate CO vibrational modes.
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24
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Park JY, Kwon HJ, Mondal S, Han H, Kwak K, Cho M. Two-dimensional IR spectroscopy reveals a hidden Fermi resonance band in the azido stretch spectrum of β-azidoalanine. Phys Chem Chem Phys 2020; 22:19223-19229. [PMID: 32812969 DOI: 10.1039/d0cp02693j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Azido stretch modes in a variety of azido-derivatized nonnatural amino acids and nucleotides have been used as a site-specific infrared (IR) probe for monitoring changes in their conformations and local electrostatic environments. The vibrational bands of azide probes are often accompanied by complex line shapes with shoulder peaks, which may arise either from incomplete background subtraction, Fermi resonance, or multiple conformers. The isotope substitution in the infrared probe has thus been introduced to remove Fermi resonances without causing a significant perturbation to the structure. Here, we synthesized and labeled the mid-N atoms of aliphatic azide derivatives with 15N to study the effects of isotope labelling on their vibrational properties. The FT-IR spectra of the aliphatic azide with asymmetric lineshape became a single symmetric band upon isotope substitution, which might be an indication of the removal of the hidden Fermi resonance from the system. We also noticed that the 2D-IR spectrum of unlabeled aliphatic azide has cross-peaks, even though it is not apparently identifiable. The 1D slice spectra obtained from the 2D-IR spectra reveal the existence of a hidden Fermi resonance peak. Furthermore, we show that this weak Fermi resonance does not produce discernible oscillatory beating patterns in the IR pump-probe spectrum, which has been used as evidence of the Fermi resonance. Therefore, we confirm that isotope labelling combined with 2D-IR spectroscopy is the most efficient and incisive way to identify the origin of small shoulder peaks in the linear and nonlinear vibrational spectra of various IR probe molecules.
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Affiliation(s)
- Jun Young Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Republic of Korea. and Department of Chemistry, Korea University, Seoul 02841, Republic of Korea.
| | - Hyeok-Jun Kwon
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea.
| | - Saptarsi Mondal
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Republic of Korea. and Department of Chemistry, Korea University, Seoul 02841, Republic of Korea.
| | - Hogyu Han
- Department of Chemistry, Korea University, Seoul 02841, Republic of Korea.
| | - Kyungwon Kwak
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Republic of Korea. and Department of Chemistry, Korea University, Seoul 02841, Republic of Korea.
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Republic of Korea. and Department of Chemistry, Korea University, Seoul 02841, Republic of Korea.
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25
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Park JY, Mondal S, Kwon HJ, Sahu PK, Han H, Kwak K, Cho M. Effect of isotope substitution on the Fermi resonance and vibrational lifetime of unnatural amino acids modified with IR probe: A 2D-IR and pump-probe study of 4-azido-L-phenyl alanine. J Chem Phys 2020; 153:164309. [DOI: 10.1063/5.0025289] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jun Young Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, South Korea
- Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Saptarsi Mondal
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, South Korea
- Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Hyeok-Jun Kwon
- Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Prabhat Kumar Sahu
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, South Korea
- Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Hogyu Han
- Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Kyungwon Kwak
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, South Korea
- Department of Chemistry, Korea University, Seoul 02841, South Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, South Korea
- Department of Chemistry, Korea University, Seoul 02841, South Korea
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26
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Flanagan JC, Cardenas AE, Baiz CR. Ultrafast Spectroscopy of Lipid-Water Interfaces: Transmembrane Crowding Drives H-Bond Dynamics. J Phys Chem Lett 2020; 11:4093-4098. [PMID: 32364385 DOI: 10.1021/acs.jpclett.0c00783] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Biology takes place in crowded, heterogeneous environments, and it is therefore essential to account for crowding effects in our understanding of biophysical processes at the molecular level. Comparable to the cytosol, proteins occupy approximately 30% of the plasma membrane surface; thus, crowding should have an effect on the local structure and dynamics at the lipid-water interface. Using a combination of ultrafast two-dimensional infrared spectroscopy and molecular dynamics simulations, we quantify the effects of membrane peptide concentration on the picosecond interfacial H-bond dynamics. The measurements reveal a nonmonotonic dependence of water orientation and dynamics as a function of transmembrane peptide:lipid ratio. We observe three dynamical regimes: a "pure lipid-like" regime at low peptide concentrations, a bulk-like region at intermediate peptide concentrations where dynamics are faster by ∼20% compared to those of the pure lipid bilayer, and a crowded regime where high peptide concentrations slow dynamics by ∼50%.
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27
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Kendrick WJ, Jirásek M, Peeks MD, Greetham GM, Sazanovich IV, Donaldson PM, Towrie M, Parker AW, Anderson HL. Mechanisms of IR amplification in radical cation polarons. Chem Sci 2020; 11:2112-2120. [PMID: 34123299 PMCID: PMC8150116 DOI: 10.1039/c9sc05717j] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 12/12/2019] [Indexed: 12/30/2022] Open
Abstract
Break down of the Born-Oppenheimer approximation is caused by mixing of electronic and vibrational transitions in the radical cations of some conjugated polymers, resulting in unusually intense vibrational bands known as infrared active vibrations (IRAVs). Here, we investigate the mechanism of this amplification, and show that it provides insights into intramolecular charge migration. Spectroelectrochemical time-resolved infrared (TRIR) and two-dimensional infrared (2D-IR) spectroscopies were used to investigate the radical cations of two butadiyne-linked conjugated porphyrin oligomers, a linear dimer and a cyclic hexamer. The 2D-IR spectra reveal strong coupling between all the IRAVs and the electronic π-π* polaron band. Intramolecular vibrational energy redistribution (IVR) and vibrational relaxation occur within ∼0.1-7 ps. TRIR spectra show that the transient ground state bleach (GSB) and excited state absorption (ESA) signals have anisotropies of 0.31 ± 0.07 and 0.08 ± 0.04 for the linear dimer and cyclic hexamer cations, respectively. The small TRIR anisotropy for the cyclic hexamer radical cation indicates that the vibrationally excited polaron migrates round the nanoring on a time scale faster than the measurement, i.e. within 0.5 ps, at 298 K. Density functional theory (DFT) calculations qualitatively reproduce the emergence of the IRAVs. The first singlet (S1) excited states of the neutral porphyrin oligomers exhibit similar IRAVs to the radical cations, implying that the excitons have similar electronic structures to polarons. Our results show that IRAVs originate from the strong coupling of charge redistribution to nuclear motion, and from the similar energies of electronic and vibrational transitions.
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Affiliation(s)
- William J Kendrick
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Michael Jirásek
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Martin D Peeks
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
| | - Gregory M Greetham
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Igor V Sazanovich
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Paul M Donaldson
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Anthony W Parker
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities Council Didcot OX11 0QX UK
| | - Harry L Anderson
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK
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28
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Portius P, Bühl M, George MW, Grevels FW, Turner JJ. Structure and Dynamics of Iron Pentacarbonyl. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00559] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter Portius
- Department of Chemistry, The University of Sheffield, Western Bank, Sheffield S3 7HF, United Kingdom
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Michael Bühl
- School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom
| | - Michael W. George
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo 315100, China
| | - Friedrich-Wilhelm Grevels
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstraße 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - James J. Turner
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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29
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Baryiames CP, Teel M, Baiz CR. Interfacial H-Bond Dynamics in Reverse Micelles: The Role of Surfactant Heterogeneity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11463-11470. [PMID: 31407910 DOI: 10.1021/acs.langmuir.9b01693] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Characterizing the hydrogen bond structure and dynamics at surfactant interfaces is essential for understanding how microscopic interactions translate to bulk microemulsion properties. Heterogeneous blends containing tens or hundreds of surfactants are common in the industry, but the most fundamental studies have been carried out on micelles composed of a single surfactant species. Therefore, the effect of surfactant heterogeneity on the interfacial structure and dynamics remains poorly understood. Here, we use ultrafast two-dimensional infrared spectroscopy and molecular dynamics simulations to characterize sub-picosecond solvation dynamics as a function of the surfactant composition in ∼120 nm water-in-oil reverse micelles. We probe the ester carbonyl vibrations of nonionic sorbitan surfactants, which are located precisely at the interface between the polar and nonpolar regions, and as such, report on the interfacial water dynamics. We show a 7% increase in hydrogen bond populations together with a 37% slowdown of interfacial hydrogen bond dynamics in heterogeneous mixtures containing hundreds of species, compared to more uniform compositions. Simulations, which are in semiquantitative agreement with experiments, indicate that structural diversity leads to decreased packing efficiency, which in turn drives water further into the otherwise hydrophobic region. Interestingly, this increase in hydration is accompanied by a slowdown of dynamics, indicating that water molecules solvating surfactants are conformationally constrained. These studies demonstrate that the composition and heterogeneity are key factors in determining interfacial properties.
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Affiliation(s)
| | - Morgan Teel
- University of Texas at Austin , Austin 78712 , Texas , United States
| | - Carlos R Baiz
- University of Texas at Austin , Austin 78712 , Texas , United States
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30
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Humston JJ, Bhattacharya I, Jacob M, Cheatum CM. Optimized reconstructions of compressively sampled two-dimensional infrared spectra. J Chem Phys 2019; 150:234202. [PMID: 31228910 DOI: 10.1063/1.5097946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Compressive sampling has the potential to dramatically accelerate the pace of data collection in two-dimensional infrared (2D IR) spectroscopy. We have previously introduced the Generic Iteratively Reweighted Annihilating Filter (GIRAF) reconstruction algorithm to solve the reconstruction in 2D IR compressive sampling. Here, we report a thorough assessment of this method and comparison to our earlier efforts using the Total Variation (TV) algorithm. We show that the GIRAF algorithm has some distinct advantages over TV. Although it is no better or worse in terms of ameliorating the impacts of compressive sampling on the measured 2D IR line shape, we find that the nature of those effects is different for GIRAF than they were for TV. In addition to assessing the impacts on the line shape of a single oscillator, we also test the ability of the algorithm to reconstruct spectra that have transitions from more than one oscillator, such as the coupled carbonyl oscillators in rhodium dicarbonyl. Finally, and perhaps most importantly, we show that the GIRAF algorithm has a distinct denoising effect on the signal-to-noise ratio (SNR) of the 2D IR spectra that can increase the SNR by as much as 4× without any additional signal averaging and collecting fewer data points, which should further enhance the acceleration of data collection that can be achieved using compressive sampling and enable even more challenging experimental measurements.
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Affiliation(s)
| | - Ipshita Bhattacharya
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa 52242, USA
| | - Mathews Jacob
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa 52242, USA
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31
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Edington SC, Halling DB, Bennett SM, Middendorf TR, Aldrich RW, Baiz CR. Non-Additive Effects of Binding Site Mutations in Calmodulin. Biochemistry 2019; 58:2730-2739. [PMID: 31124357 DOI: 10.1021/acs.biochem.9b00096] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Despite decades of research on ion-sensing proteins, gaps persist in the understanding of ion binding affinity and selectivity even in well-studied proteins such as calmodulin. Site-directed mutagenesis is a powerful and popular tool for addressing outstanding questions about biological ion binding and is employed to selectively deactivate binding sites and insert chromophores at advantageous positions within ion binding structures. However, even apparently nonperturbative mutations can distort the binding dynamics they are employed to measure. We use Fourier transform infrared (FTIR) and ultrafast two-dimensional infrared (2D IR) spectroscopy of the carboxylate asymmetric stretching mode in calmodulin as a mutation- and label-independent probe of the conformational perturbations induced in calmodulin's binding sites by two classes of mutation, tryptophan insertion and carboxylate side-chain deletion, commonly used to study ion binding in proteins. Our results show that these mutations not only affect ion binding but also induce changes in calmodulin's conformational landscape along coordinates not probed by vibrational spectroscopy, remaining invisible without additional perturbation of binding site structure. Comparison of FTIR line shapes with 2D IR diagonal slices provides a clear example of how nonlinear spectroscopy produces well-resolved line shapes, refining otherwise featureless spectral envelopes into more informative vibrational spectra of proteins.
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Affiliation(s)
- Sean C Edington
- Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - D Brent Halling
- Department of Neuroscience , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Suzanna M Bennett
- Department of Neuroscience , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Thomas R Middendorf
- Department of Neuroscience , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Richard W Aldrich
- Department of Neuroscience , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Carlos R Baiz
- Department of Chemistry , The University of Texas at Austin , Austin , Texas 78712 , United States
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32
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Kossowska D, Park K, Park JY, Lim C, Kwak K, Cho M. Rational Design of an Acetylenic Infrared Probe with Enhanced Dipole Strength and Increased Vibrational Lifetime. J Phys Chem B 2019; 123:6274-6281. [DOI: 10.1021/acs.jpcb.9b04925] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Dorota Kossowska
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Kwanghee Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
| | - Jun Young Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Chaiho Lim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Kyungwon Kwak
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
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33
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Blankenburg L, Schroeder L, Habenstein F, Błasiak B, Kottke T, Bredenbeck J. Following local light-induced structure changes and dynamics of the photoreceptor PYP with the thiocyanate IR label. Phys Chem Chem Phys 2019; 21:6622-6634. [PMID: 30855039 DOI: 10.1039/c8cp05399e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoactive Yellow Protein (PYP) is a bacterial blue light receptor that enters a photocycle after excitation. The intermediate states are formed on time scales ranging from femtoseconds up to hundreds of milliseconds, after which the signaling state with a lifetime of about 1 s is reached. To investigate structural changes and dynamics, we incorporated the SCN IR label at distinct positions of the photoreceptor via cysteine mutation and cyanylation. FT-IR measurements of the SCN label at different sites of the well-established dark state structure of PYP characterized the spectral response of the label to differences in the environment. Under constant blue light irradiation, we observed the formation of the signaling state with significant changes of wavenumber and lineshape of the SCN bands. Thereby we deduced light-induced structural changes in the local environment of the labels. These results were supported by molecular dynamics simulations on PYP providing the solvent accessible surface area (SASA) at the different positions. To follow protein dynamics via the SCN label during the photocycle, we performed step-scan FT-IR measurements with a time resolution of 10 μs. Global analysis yielded similar time constants of τ1 = 70 μs, τ2 = 640 μs, and τ3 > 20 ms for the wild type and τ1 = 36 μs, τ2 = 530 μs, and τ3 > 20 ms for the SCN-labeled mutant PYP-A44C*, a mutant which provided a sufficiently large SCN difference signal to measure step-scan FT-IR spectra. In comparison to the protein (amide, E46) and chromophore bands the dynamics of the SCN label show a different behavior. This result indicates that the local kinetics sensed by the label are different from the global protein kinetics.
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Affiliation(s)
- Larissa Blankenburg
- Johann Wolfgang Goethe-University, Institute of Biophysics, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany.
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34
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Site-Specific Peptide Probes Detect Buried Water in a Lipid Membrane. Biophys J 2019; 116:1692-1700. [PMID: 31000156 DOI: 10.1016/j.bpj.2019.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 01/08/2023] Open
Abstract
Transmembrane peptides contain polar residues in the interior of the membrane, which may alter the electrostatic environment and favor hydration in the otherwise nonpolar environment of the membrane core. Here, we demonstrate a general, nonperturbative strategy to probe hydration of the peptide backbone at specific depths within the bilayer using a combination of site-specific isotope labels, ultrafast two-dimensional infrared spectroscopy, and spectral modeling based on molecular dynamics simulations. Our results show that the amphiphilic pH-low insertion peptide supports a highly heterogeneous environment, with significant backbone hydration of nonpolar residues neighboring charged residues. For example, a leucine residue located as far as 1 nm into the hydrophobic bulk reports hydrogen-bonded populations as high as ∼20%. These findings indicate that the polar nature of these residues may facilitate the transport of water molecules into the hydrophobic core of the membrane.
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35
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Kossowska D, Lee G, Han H, Kwak K, Cho M. Simultaneous enhancement of transition dipole strength and vibrational lifetime of an alkyne IR probe via π-d backbonding and vibrational decoupling. Phys Chem Chem Phys 2019; 21:24919-24925. [DOI: 10.1039/c9cp04356j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Alkyne IR probes 1–6 with Si and S (or Se) atoms incorporated into the CC bond were synthesized, and the vibrational properties of their CC stretch mode were studied using FTIR and femtosecond IR PP spectroscopies and quantum chemical calculations.
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Affiliation(s)
- Dorota Kossowska
- Center for Molecular Spectroscopy and Dynamics
- Institute for Basic Science (IBS)
- Seoul 02841
- Korea
- Department of Chemistry
| | - Giseong Lee
- Department of Chemistry
- Korea University
- Seoul 02841
- Korea
| | - Hogyu Han
- Department of Chemistry
- Korea University
- Seoul 02841
- Korea
| | - Kyungwon Kwak
- Center for Molecular Spectroscopy and Dynamics
- Institute for Basic Science (IBS)
- Seoul 02841
- Korea
- Department of Chemistry
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics
- Institute for Basic Science (IBS)
- Seoul 02841
- Korea
- Department of Chemistry
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36
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Deniz E, Eberl KB, Bredenbeck J. Note: An automatic liquid nitrogen refilling system for small (detector) Dewar vessels. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:116101. [PMID: 30501329 DOI: 10.1063/1.5046637] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/18/2018] [Indexed: 06/09/2023]
Abstract
Many infrared spectroscopy setups are in principle stable enough to run overnight or longer, but the detector's Dewar vessel must be refilled manually with liquid nitrogen (LN2) every couple of hours. Commercial automatic LN2 refilling systems work reliably only for large Dewars. Here, we present a refilling system which can non-invasively be applied to already installed small Dewars. The system reliably refills LN2 once it has dropped below an adjustable level, with quick refilling (<3 min) for a 0.6 l Dewar. Our design protects the setup and the detector from overflowing or running without LN2.
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Affiliation(s)
- E Deniz
- Institute of Biophysics, Goethe University Frankfurt am Main, Frankfurt am Main 60438, Germany
| | - K B Eberl
- Institute of Biophysics, Goethe University Frankfurt am Main, Frankfurt am Main 60438, Germany
| | - J Bredenbeck
- Institute of Biophysics, Goethe University Frankfurt am Main, Frankfurt am Main 60438, Germany
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37
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Blaffert J, Haeri HH, Blech M, Hinderberger D, Garidel P. Spectroscopic methods for assessing the molecular origins of macroscopic solution properties of highly concentrated liquid protein solutions. Anal Biochem 2018; 561-562:70-88. [PMID: 30243977 DOI: 10.1016/j.ab.2018.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 09/08/2018] [Accepted: 09/17/2018] [Indexed: 01/14/2023]
Abstract
In cases of subcutaneous injection of therapeutic monoclonal antibodies, high protein concentrations (>50 mg/ml) are often required. During the development of these high concentration liquid formulations (HCLF), challenges such as aggregation, gelation, opalescence, phase separation, and high solution viscosities are more prone compared to low concentrated protein formulations. These properties can impair manufacturing processes, as well as protein stability and shelf life. To avoid such unfavourable solution properties, a detailed understanding about the nature of these properties and their driving forces are required. However, the fundamental mechanisms that lead to macroscopic solution properties, as above mentioned, are complex and not fully understood, yet. Established analytical methods for assessing the colloidal stability, i.e. the ability of a native protein to remain dispersed in solution, are restricted to dilute conditions and provide parameters such as the second osmotic virial coefficient, B22, and the diffusion interaction coefficient, kD. These parameters are routinely applied for qualitative estimations and identifications of proteins with challenging solution behaviours, such as high viscosities and aggregation, although the assays are prepared for low protein concentration conditions, typically between 0.1 and 20 mg/ml ("ideal" solution conditions). Quantitative analysis of samples of high protein concentration is difficult and it is hard to obtain information about the driving forces of such solution properties and corresponding protein-protein self-interactions. An advantage of using specific spectroscopic methods is the potential of directly analysing highly concentrated protein solutions at different solution conditions. This allows for collecting/gaining valuable information about the fundamental mechanisms of solution properties of the high protein concentration regime. In addition, the derived parameters might be more predictive as compared to the parameters originating from assays which are optimized for the low protein concentration range. The provided information includes structural data, molecular dynamics at various timescales and protein-solvent interactions, which can be obtained at molecular resolution. Herein, we provide an overview about spectroscopic techniques for analysing the origins of macroscopic solution behaviours in general, with a specific focus on pharmaceutically relevant high protein concentration and formulation conditions.
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Affiliation(s)
- Jacob Blaffert
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany
| | - Haleh Hashemi Haeri
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany
| | - Michaela Blech
- Boehringer Ingelheim Pharma GmbH & Co. KG, Protein Science, Birkerndorfer Str. 65, 88397, Biberach/Riß, Germany
| | - Dariush Hinderberger
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany
| | - Patrick Garidel
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany; Boehringer Ingelheim Pharma GmbH & Co. KG, Protein Science, Birkerndorfer Str. 65, 88397, Biberach/Riß, Germany.
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38
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Hogle DG, Cunningham AR, Tucker MJ. Equilibrium versus Nonequilibrium Peptide Dynamics: Insights into Transient 2D IR Spectroscopy. J Phys Chem B 2018; 122:8783-8795. [PMID: 30040900 DOI: 10.1021/acs.jpcb.8b05063] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Over the past two decades, two-dimensional infrared (2D IR) spectroscopy has evolved from the theoretical underpinnings of nonlinear spectroscopy as a means of investigating detailed molecular structure on an ultrafast time scale. The combined time and spectral resolution over which spectra can be collected on complex molecular systems has led to the precise structural resolution of dynamic species that have previously been impossible to directly observe through traditional methods. The adoption of 2D IR spectroscopy for the study of protein folding and peptide interactions has provided key details of how small changes in conformations can exert major influences on the activities of these complex molecular systems. Traditional 2D IR experiments are limited to molecules under equilibrium conditions, where small motions and fluctuations of these larger molecules often still lead to functionality. Utilizing techniques that allow the rapid initiation of chemical or structural changes in conjunction with 2D IR spectroscopy, i.e., transient 2D IR, a vast dynamic range becomes available to the spectroscopist uncovering structural content far from equilibrium. Furthermore, this allows the observation of reaction pathways of these macromolecules under quasi- and nonequilibrium conditions.
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Affiliation(s)
- David G Hogle
- Department of Chemistry , University of Nevada, Reno , 1664 North Virginia Street , Reno , Nevada 89557 , United States
| | - Amy R Cunningham
- Department of Chemistry , University of Nevada, Reno , 1664 North Virginia Street , Reno , Nevada 89557 , United States
| | - Matthew J Tucker
- Department of Chemistry , University of Nevada, Reno , 1664 North Virginia Street , Reno , Nevada 89557 , United States
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39
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Affiliation(s)
- Sean C. Edington
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Carlos R. Baiz
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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40
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Abstract
The temperature dependence of the low-frequency C-O bands in the IR spectrum of [(η4-norbornadiene)Fe(CO)3], reminiscent of signal coalescence in dynamic NMR, was interpreted by Grevels (in 1987) as chemical exchange due to very fast rotation of the diene group. Since then, there has been both support and objection to this interpretation. We discuss these various claims involving both one- and two-dimensional IR and, largely on the basis of new density functional theory calculations, furnish support for Grevels' original interpretation.
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Affiliation(s)
- James J Turner
- School of Chemistry , University of Nottingham, University Park , Nottingham NG7 2RD , United Kingdom
| | - Michael Bühl
- School of Chemistry , University of St. Andrews , St. Andrews , Fife KY16 9ST , United Kingdom
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41
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Abstract
Exciting new technological developments have pushed the boundaries of structural biology, and have enabled studies of biological macromolecules and assemblies that would have been unthinkable not long ago. Yet, the enhanced capabilities of structural biologists to pry into the complex molecular world have also placed new demands on the abilities of protein engineers to reproduce this complexity into the test tube. With this challenge in mind, we review the contents of the modern molecular engineering toolbox that allow the manipulation of proteins in a site-specific and chemically well-defined fashion. Thus, we cover concepts related to the modification of cysteines and other natural amino acids, native chemical ligation, intein and sortase-based approaches, amber suppression, as well as chemical and enzymatic bio-conjugation strategies. We also describe how these tools can be used to aid methodology development in X-ray crystallography, nuclear magnetic resonance, cryo-electron microscopy and in the studies of dynamic interactions. It is our hope that this monograph will inspire structural biologists and protein engineers alike to apply these tools to novel systems, and to enhance and broaden their scope to meet the outstanding challenges in understanding the molecular basis of cellular processes and disease.
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42
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Coordination to lanthanide ions distorts binding site conformation in calmodulin. Proc Natl Acad Sci U S A 2018; 115:E3126-E3134. [PMID: 29545272 DOI: 10.1073/pnas.1722042115] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The Ca2+-sensing protein calmodulin (CaM) is a popular model of biological ion binding since it is both experimentally tractable and essential to survival in all eukaryotic cells. CaM modulates hundreds of target proteins and is sensitive to complex patterns of Ca2+ exposure, indicating that it functions as a sophisticated dynamic transducer rather than a simple on/off switch. Many details of this transduction function are not well understood. Fourier transform infrared (FTIR) spectroscopy, ultrafast 2D infrared (2D IR) spectroscopy, and electronic structure calculations were used to probe interactions between bound metal ions (Ca2+ and several trivalent lanthanide ions) and the carboxylate groups in CaM's EF-hand ion-coordinating sites. Since Tb3+ is commonly used as a luminescent Ca2+ analog in studies of protein-ion binding, it is important to characterize distinctions between the coordination of Ca2+ and the lanthanides in CaM. Although functional assays indicate that Tb3+ fully activates many Ca2+-dependent proteins, our FTIR spectra indicate that Tb3+, La3+, and Lu3+ disrupt the bidentate coordination geometry characteristic of the CaM binding sites' strongly conserved position 12 glutamate residue. The 2D IR spectra indicate that, relative to the Ca2+-bound form, lanthanide-bound CaM exhibits greater conformational flexibility and larger structural fluctuations within its binding sites. Time-dependent 2D IR lineshapes indicate that binding sites in Ca2+-CaM occupy well-defined configurations, whereas binding sites in lanthanide-bound-CaM are more disordered. Overall, the results show that binding to lanthanide ions significantly alters the conformation and dynamics of CaM's binding sites.
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43
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Lee G, Kossowska D, Lim J, Kim S, Han H, Kwak K, Cho M. Cyanamide as an Infrared Reporter: Comparison of Vibrational Properties between Nitriles Bonded to N and C Atoms. J Phys Chem B 2018. [DOI: 10.1021/acs.jpcb.8b00887] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Giseong Lee
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Dorota Kossowska
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Joonhyung Lim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Soobin Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
| | - Hogyu Han
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Kyungwon Kwak
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Minhaeng Cho
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Korea
- Department of Chemistry, Korea University, Seoul 02841, Korea
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44
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Reppert M, Brumer P. Classical coherent two-dimensional vibrational spectroscopy. J Chem Phys 2018; 148:064101. [DOI: 10.1063/1.5017985] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mike Reppert
- Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Paul Brumer
- Chemical Physics Theory Group, Department of Chemistry, and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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45
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Kern-Michler D, Neumann C, Mielke N, van Wilderen LJGW, Reinfelds M, von Cosel J, Santoro F, Heckel A, Burghardt I, Bredenbeck J. Controlling Photochemistry via Isotopomers and IR Pre-excitation. J Am Chem Soc 2018; 140:926-931. [PMID: 29182322 DOI: 10.1021/jacs.7b08723] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
It is a photochemist's dream to be able to photoinduce a reaction of a specific molecular species in an ensemble of similar but not identical ones. The problem is that similar molecules often exhibit nearly identical UV-Vis absorption spectra, making them difficult or impossible to distinguish or to select spectroscopically. The ultrafast VIPER (VIbrationally Promoted Electronic Resonance) pulse sequence allows to pick a single species for electronic excitation based on its infrared spectrum. The latter usually shows more features, allowing the discrimination between species than the UV-Vis spectrum. Here, we show that it is possible to induce and monitor species-selective photochemistry even for molecules with virtually identical UV-Vis spectra, which is the case for isotopomers. Next to isotope-selective photochemistry in solution, applications to orthogonal photo-uncaging and species-selective spectroscopy and photochemistry in mixtures are within reach.
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Affiliation(s)
- Daniela Kern-Michler
- Institute of Biophysics, Goethe University Frankfurt , Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Carsten Neumann
- Institute of Biophysics, Goethe University Frankfurt , Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Nicole Mielke
- Institute of Biophysics, Goethe University Frankfurt , Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Luuk J G W van Wilderen
- Institute of Biophysics, Goethe University Frankfurt , Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
| | - Matiss Reinfelds
- Institute of Organic Chemistry and Chemical Biology, Goethe University Frankfurt , Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Jan von Cosel
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt , Max-von-Laue Str. 7, 60438 Frankfurt am Main, Germany
| | - Fabrizio Santoro
- Consiglio Nazionale delle Ricerche (CNR), Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR) , UOS di Pisa, Via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Alexander Heckel
- Institute of Organic Chemistry and Chemical Biology, Goethe University Frankfurt , Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Irene Burghardt
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt , Max-von-Laue Str. 7, 60438 Frankfurt am Main, Germany
| | - Jens Bredenbeck
- Institute of Biophysics, Goethe University Frankfurt , Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany
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46
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Kraack JP. Ultrafast structural molecular dynamics investigated with 2D infrared spectroscopy methods. Top Curr Chem (Cham) 2017; 375:86. [PMID: 29071445 DOI: 10.1007/s41061-017-0172-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 10/02/2017] [Indexed: 12/23/2022]
Abstract
Ultrafast, multi-dimensional infrared (IR) spectroscopy has been advanced in recent years to a versatile analytical tool with a broad range of applications to elucidate molecular structure on ultrafast timescales, and it can be used for samples in a many different environments. Following a short and general introduction on the benefits of 2D IR spectroscopy, the first part of this chapter contains a brief discussion on basic descriptions and conceptual considerations of 2D IR spectroscopy. Outstanding classical applications of 2D IR are used afterwards to highlight the strengths and basic applicability of the method. This includes the identification of vibrational coupling in molecules, characterization of spectral diffusion dynamics, chemical exchange of chemical bond formation and breaking, as well as dynamics of intra- and intermolecular energy transfer for molecules in bulk solution and thin films. In the second part, several important, recently developed variants and new applications of 2D IR spectroscopy are introduced. These methods focus on (i) applications to molecules under two- and three-dimensional confinement, (ii) the combination of 2D IR with electrochemistry, (iii) ultrafast 2D IR in conjunction with diffraction-limited microscopy, (iv) several variants of non-equilibrium 2D IR spectroscopy such as transient 2D IR and 3D IR, and (v) extensions of the pump and probe spectral regions for multi-dimensional vibrational spectroscopy towards mixed vibrational-electronic spectroscopies. In light of these examples, the important open scientific and conceptual questions with regard to intra- and intermolecular dynamics are highlighted. Such questions can be tackled with the existing arsenal of experimental variants of 2D IR spectroscopy to promote the understanding of fundamentally new aspects in chemistry, biology and materials science. The final part of the chapter introduces several concepts of currently performed technical developments, which aim at exploiting 2D IR spectroscopy as an analytical tool. Such developments embrace the combination of 2D IR spectroscopy and plasmonic spectroscopy for ultrasensitive analytics, merging 2D IR spectroscopy with ultra-high-resolution microscopy (nanoscopy), future variants of transient 2D IR methods, or 2D IR in conjunction with microfluidics. It is expected that these techniques will allow for groundbreaking research in many new areas of natural sciences.
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Affiliation(s)
- Jan Philip Kraack
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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47
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Ayres CM, Corcelli SA, Baker BM. Peptide and Peptide-Dependent Motions in MHC Proteins: Immunological Implications and Biophysical Underpinnings. Front Immunol 2017; 8:935. [PMID: 28824655 PMCID: PMC5545744 DOI: 10.3389/fimmu.2017.00935] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/21/2017] [Indexed: 01/28/2023] Open
Abstract
Structural biology of peptides presented by class I and class II MHC proteins has transformed immunology, impacting our understanding of fundamental immune mechanisms and allowing researchers to rationalize immunogenicity and design novel vaccines. However, proteins are not static structures as often inferred from crystallographic structures. Their components move and breathe individually and collectively over a range of timescales. Peptides bound within MHC peptide-binding grooves are no exception and their motions have been shown to impact recognition by T cell and other receptors in ways that influence function. Furthermore, peptides tune the motions of MHC proteins themselves, which impacts recognition of peptide/MHC complexes by other proteins. Here, we review the motional properties of peptides in MHC binding grooves and discuss how peptide properties can influence MHC motions. We briefly review theoretical concepts about protein motion and highlight key data that illustrate immunological consequences. We focus primarily on class I systems due to greater availability of data, but segue into class II systems as the concepts and consequences overlap. We suggest that characterization of the dynamic “energy landscapes” of peptide/MHC complexes and the resulting functional consequences is one of the next frontiers in structural immunology.
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Affiliation(s)
- Cory M Ayres
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Steven A Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
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Pindelska E, Sokal A, Kolodziejski W. Pharmaceutical cocrystals, salts and polymorphs: Advanced characterization techniques. Adv Drug Deliv Rev 2017; 117:111-146. [PMID: 28931472 DOI: 10.1016/j.addr.2017.09.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/21/2017] [Accepted: 09/14/2017] [Indexed: 12/11/2022]
Abstract
The main goal of a novel drug development is to obtain it with optimal physiochemical, pharmaceutical and biological properties. Pharmaceutical companies and scientists modify active pharmaceutical ingredients (APIs), which often are cocrystals, salts or carefully selected polymorphs, to improve the properties of a parent drug. To find the best form of a drug, various advanced characterization methods should be used. In this review, we have described such analytical methods, dedicated to solid drug forms. Thus, diffraction, spectroscopic, thermal and also pharmaceutical characterization methods are discussed. They all are necessary to study a solid API in its intrinsic complexity from bulk down to the molecular level, gain information on its structure, properties, purity and possible transformations, and make the characterization efficient, comprehensive and complete. Furthermore, these methods can be used to monitor and investigate physical processes, involved in the drug development, in situ and in real time. The main aim of this paper is to gather information on the current advancements in the analytical methods and highlight their pharmaceutical relevance.
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Choosing the optimal spectroscopic toolkit to understand protein function. Biosci Rep 2017; 37:BSR20160378. [PMID: 28522552 PMCID: PMC5463260 DOI: 10.1042/bsr20160378] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/16/2017] [Accepted: 05/18/2017] [Indexed: 12/02/2022] Open
Abstract
Spectroscopy was one of the earliest methods used to study the properties and reactions of proteins, and remains one of the most powerful and widely used approaches to this day. A sometimes bewildering range of spectroscopies is now available, applicable to different sample states, timescales and indeed biological questions. This editorial describes some of the most relevant spectroscopic methods together with a selection of illustrative examples.
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Le Sueur AL, Ramos S, Ellefsen JD, Cook S, Thielges MC. Evaluation of p-(13C,15N-Cyano)phenylalanine as an Extended Time Scale 2D IR Probe of Proteins. Anal Chem 2017; 89:5254-5260. [DOI: 10.1021/acs.analchem.6b04650] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Amanda L. Le Sueur
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Sashary Ramos
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Jonathan D. Ellefsen
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Silas Cook
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Megan C. Thielges
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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