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Osifová Z, Kalvoda T, Galgonek J, Culka M, Vondrášek J, Bouř P, Bednárová L, Andrushchenko V, Dračínský M, Rulíšek L. What are the minimal folding seeds in proteins? Experimental and theoretical assessment of secondary structure propensities of small peptide fragments. Chem Sci 2024; 15:594-608. [PMID: 38179543 PMCID: PMC10763034 DOI: 10.1039/d3sc04960d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/22/2023] [Indexed: 01/06/2024] Open
Abstract
Certain peptide sequences, some of them as short as amino acid triplets, are significantly overpopulated in specific secondary structure motifs in folded protein structures. For example, 74% of the EAM triplet is found in α-helices, and only 3% occurs in the extended parts of proteins (typically β-sheets). In contrast, other triplets (such as VIV and IYI) appear almost exclusively in extended parts (79% and 69%, respectively). In order to determine whether such preferences are structurally encoded in a particular peptide fragment or appear only at the level of a complex protein structure, NMR, VCD, and ECD experiments were carried out on selected tripeptides: EAM (denoted as pro-'α-helical' in proteins), KAM(α), ALA(α), DIC(α), EKF(α), IYI(pro-β-sheet or more generally, pro-extended), and VIV(β), and the reference α-helical CATWEAMEKCK undecapeptide. The experimental data were in very good agreement with extensive quantum mechanical conformational sampling. Altogether, we clearly showed that the pro-helical vs. pro-extended propensities start to emerge already at the level of tripeptides and can be fully developed at longer sequences. We postulate that certain short peptide sequences can be considered minimal "folding seeds". Admittedly, the inherent secondary structure propensity can be overruled by the large intramolecular interaction energies within the folded and compact protein structures. Still, the correlation of experimental and computational data presented herein suggests that the secondary structure propensity should be considered as one of the key factors that may lead to understanding the underlying physico-chemical principles of protein structure and folding from the first principles.
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Affiliation(s)
- Zuzana Osifová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
- Department of Organic Chemistry, Faculty of Science, Charles University Hlavova 2030 Prague 128 00 Czech Republic
| | - Tadeáš Kalvoda
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Jakub Galgonek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Martin Culka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Jiří Vondrášek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Lucie Bednárová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Martin Dračínský
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
| | - Lubomír Rulíšek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2, 160 00, Praha 6 Czech Republic
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2
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Zubova EA, Strelnikov IA. Experimental detection of conformational transitions between forms of DNA: problems and prospects. Biophys Rev 2023; 15:1053-1078. [PMID: 37974981 PMCID: PMC10643659 DOI: 10.1007/s12551-023-01143-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 09/06/2023] [Indexed: 11/19/2023] Open
Abstract
Under different conditions, the DNA double helix can take different geometric forms. Of the large number of its conformations, in addition to the "canonical" B form, the A, C, and Z forms are widely known, and the D, Hoogsteen, and X forms are less known. DNA locally takes the A, C, and Z forms in the cell, in complexes with proteins. We compare different methods for detecting non-canonical DNA conformations: X-ray, IR, and Raman spectroscopy, linear and circular dichroism in both the infrared and ultraviolet regions, as well as NMR (measurement of chemical shifts and their anisotropy, scalar and residual dipolar couplings and inter-proton distances from NOESY (nuclear Overhauser effect spectroscopy) data). We discuss the difficulties in applying these methods, the problems of theoretical interpretation of the experimental results, and the prospects for reliable identification of non-canonical DNA conformations.
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Affiliation(s)
- Elena A. Zubova
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 4 Kosygin St., Moscow, 119991 Russia
| | - Ivan A. Strelnikov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 4 Kosygin St., Moscow, 119991 Russia
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3
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Karami A, Hasani M. Methods to functionalize gold nanoparticles with tandem-phosphorothioate DNA: role of physicochemical properties of the phosphorothioate backbone in DNA adsorption to gold nanoparticles. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2023; 15:4104-4113. [PMID: 37551768 DOI: 10.1039/d3ay00960b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Perception of the differences in the physicochemical properties of phosphorothioate DNA (PS-DNA) and phosphodiester DNA (PO-DNA) greatly aids in understanding the AuNP-DNA binding process. Replacing one non-bridging oxygen atom of the anionic phosphodiester backbone with a sulfur atom leads to a major change in the DNA adsorption mechanism of AuNPs. In this work, we investigated and compared salt-aging, low pH-assisted, and freeze-thaw methods for conjugating phosphorothioate-modified oligonucleotides to AuNPs. The results obtained clearly demonstrate that only the pH-assisted method can successfully bind tandem phosphorothioate DNA to gold nanoparticles and sufficiently maintain the colloidal stability of AuNPs. When a phosphate group is converted to a phosphorothioate group, the negative charge of the phosphate group is located on the sulfur atom. Due to the soft nature of sulfur (a very weak H-bond acceptor), the negative charge on the sulfur atom cannot be shielded even with the gradual addition of salt to increase the ionic strength, so, the pH-assisted based method is the best for the functionalization of AuNPs with tandem-PS DNA.
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Affiliation(s)
- Abbas Karami
- Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174, Iran.
| | - Masoumeh Hasani
- Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174, Iran.
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Bakker MJ, Mládek A, Semrád H, Zapletal V, Pavlíková Přecechtělová J. Improving IDP theoretical chemical shift accuracy and efficiency through a combined MD/ADMA/DFT and machine learning approach. Phys Chem Chem Phys 2022; 24:27678-27692. [PMID: 36373847 DOI: 10.1039/d2cp01638a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This work extends the multi-scale computational scheme for the quantum mechanics (QM) calculations of Nuclear Magnetic Resonance (NMR) chemical shifts (CSs) in proteins that lack a well-defined 3D structure. The scheme couples the sampling of an intrinsically disordered protein (IDP) by classical molecular dynamics (MD) with protein fragmentation using the adjustable density matrix assembler (ADMA) and density functional theory (DFT) calculations. In contrast to our early investigation on IDPs (Pavlíková Přecechtělová et al., J. Chem. Theory Comput., 2019, 15, 5642-5658) and the state-of-the art NMR calculations for structured proteins, a partial re-optimization was implemented on the raw MD geometries in vibrational normal mode coordinates to enhance the accuracy of the MD/ADMA/DFT computational scheme. In addition, machine-learning based cluster analysis was performed on the scheme to explore its potential in producing protein structure ensembles (CLUSTER ensembles) that yield accurate CSs at a reduced computational cost. The performance of the cluster-based calculations is validated against results obtained with conventional structural ensembles consisting of MD snapshots extracted from the MD trajectory at regular time intervals (REGULAR ensembles). CS calculations performed with the refined MD/ADMA/DFT framework employed the 6-311++G(d,p) basis set that outperformed IGLO-III calculations with the same density functional approximation (B3LYP) and both explicit and implicit solvation. The partial geometry optimization did not universally improve the agreement of computed CSs with the experiment but substantially decreased errors associated with the ensemble averaging. A CLUSTER ensemble with 50 structures yielded ensemble averages close to those obtained with a REGULAR ensemble consisting of 500 MD frames. The cluster based calculations thus required only a fraction of the computational time.
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Affiliation(s)
- Michael J Bakker
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
| | - Arnošt Mládek
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
| | - Hugo Semrád
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic. .,Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
| | - Vojtěch Zapletal
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
| | - Jana Pavlíková Přecechtělová
- Faculty of Pharmacy in Hradec Králové, Charles University, Akademika Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic.
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5
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Najgebauer P, Staś M, Wrzalik R, Broda MA, Wieczorek PP, Andrushchenko V, Kupka T. Muscimol hydration and vibrational spectroscopy – The impact of explicit and implicit water. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Krupová M, Leszczenko P, Sierka E, Emma Hamplová S, Pelc R, Andrushchenko V. Vibrational Circular Dichroism Unravels Supramolecular Chirality and Hydration Polymorphism of Nucleoside Crystals. Chemistry 2022; 28:e202201922. [DOI: 10.1002/chem.202201922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Monika Krupová
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Hylleraas Centre for Quantum Molecular Sciences Department of Chemistry UiT The Arctic University of Norway N-9037 Tromsø Norway
| | - Patrycja Leszczenko
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Faculty of Chemistry Jagiellonian University Gronostajowa 2 30-387 Kraków Poland
| | - Ewa Sierka
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Faculty of Chemistry Jagiellonian University Gronostajowa 2 30-387 Kraków Poland
| | - Sára Emma Hamplová
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Department of Biology and Biochemistry University of Bath Claverton Down Bath BA2 7AY United Kingdom
| | - Radek Pelc
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Third Faculty of Medicine Charles University Ruská 87 10000 Prague Czech Republic
| | - Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
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7
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Fingerhut BP. The mutual interactions of RNA, counterions and water - quantifying the electrostatics at the phosphate-water interface. Chem Commun (Camb) 2021; 57:12880-12897. [PMID: 34816825 PMCID: PMC8640580 DOI: 10.1039/d1cc05367a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/01/2021] [Indexed: 11/25/2022]
Abstract
The structure and dynamics of polyanionic biomolecules, like RNA, are decisively determined by their electric interactions with the water molecules and the counterions in the environment. The solvation dynamics of the biomolecules involves a subtle balance of non-covalent and many-body interactions with structural fluctuations due to thermal motion occurring in a femto- to subnanosecond time range. This complex fluctuating many particle scenario is crucial in defining the properties of biological interfaces with far reaching significance for the folding of RNA structures and for facilitating RNA-protein interactions. Given the inherent complexity, suited model systems, carefully calibrated and benchmarked by experiments, are required to quantify the relevant interactions of RNA with the aqueous environment. In this feature article we summarize our recent progress in the understanding of the electrostatics at the biological interface of double stranded RNA (dsRNA) and transfer RNA (tRNA). Dimethyl phosphate (DMP) is introduced as a viable and rigorously accessible model system allowing the interaction strength with water molecules and counterions, their relevant fluctuation timescales and the spatial reach of interactions to be established. We find strong (up to ≈90 MV cm-1) interfacial electric fields with fluctuations extending up to ≈20 THz and demonstrate how the asymmetric stretching vibration νAS(PO2)- of the polarizable phosphate group can serve as the most sensitive probe for interfacial interactions, establishing a rigorous link between simulations and experiment. The approach allows for the direct interfacial observation of interactions of biologically relevant Mg2+ counterions with phosphate groups in contact pair geometries via the rise of a new absorption band imposed by exchange repulsion interactions at short interatomic distances. The systematic extension to RNA provides microscopic insights into the changes of the hydration structure that accompany the temperature induced melting of the dsRNA double helix and quantify the ionic interactions in the folded tRNA. The results show that pairs of negatively charged phosphate groups and Mg2+ ions represent a key structural feature of RNA embedded in water. They highlight the importance of binding motifs made of contact pairs in the electrostatic stabilization of RNA structures that have a strong impact on the surface potential and enable the fine tuning of the local electrostatic properties which are expected to be relevant for mediating the interactions between biomolecules.
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8
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Polavarapu PL, Santoro E, Covington CL, Johnson JL, Puente AR, Schley ND, Kallingathodi Z, Prakasan PC, Haleema S, Thomas AA, Ibnusaud I. How important are the intermolecular hydrogen bonding interactions in methanol solvent for interpreting the chiroptical properties? SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 247:119094. [PMID: 33142265 DOI: 10.1016/j.saa.2020.119094] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/10/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
Two crispine A analogs and tetrahydrofuro[2,3-b]furan-3,3a(6aH)-diol, endowed with hydroxyl groups that can participate in intramolecular hydrogen bonding, have been synthesized and experimental vibrational circular dichroism (VCD) spectra and optical rotatory dispersion (ORD) data have been measured in CD3OD/CH3OH solvents. The absolute configurations (ACs) of these compounds have been determined using their synthetic schemes, supplemented wherever possible with X-ray diffraction data. The ACs are also analyzed with quantum chemical (QC) calculations of VCD and ORD utilizing implicit solvation as well as explicit solvation models, with the later employing classical molecular dynamics (MD) simulations. It is found that VCD calculations with implicit solvation model are adequate for determining the ACs, despite propensity of studied compounds for intermolecular hydrogen bonding between solute and solvent molecules. This observation is important because time-consuming MD simulations may not be necessary in the type of situations studied here. Additionally, it is found that the QC predicted VCD spectra provided enough diastereomer discrimination for determining the correct AC of studied compounds independently. The same observation did not apply to ORD.
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Affiliation(s)
| | - Ernesto Santoro
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Cody L Covington
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA; Department of Chemistry, Austin Peay State University, Clarksville, TN 37044, USA
| | - Jordan L Johnson
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Andrew R Puente
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Nathan D Schley
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA.
| | - Zabeera Kallingathodi
- Institute for Integrated Programmes and Research in Basic Sciences, Mahatma Gandhi University, Kottayam 686560, India
| | - Prasanth C Prakasan
- Institute for Integrated Programmes and Research in Basic Sciences, Mahatma Gandhi University, Kottayam 686560, India
| | - Simimole Haleema
- Institute for Integrated Programmes and Research in Basic Sciences, Mahatma Gandhi University, Kottayam 686560, India
| | - Annu Anna Thomas
- Institute for Integrated Programmes and Research in Basic Sciences, Mahatma Gandhi University, Kottayam 686560, India
| | - Ibrahim Ibnusaud
- Institute for Integrated Programmes and Research in Basic Sciences, Mahatma Gandhi University, Kottayam 686560, India.
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9
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Demissie TB, Sundar MS, Thangavel K, Andrushchenko V, Bedekar AV, Bouř P. Origins of Optical Activity in an Oxo-Helicene: Experimental and Computational Studies. ACS OMEGA 2021; 6:2420-2428. [PMID: 33521480 PMCID: PMC7841950 DOI: 10.1021/acsomega.0c06079] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 12/24/2020] [Indexed: 05/08/2023]
Abstract
Helicenes are known to provide extremely strong optical activity. Prediction of the properties of helicenes may facilitate their design and synthesis for analytical or materials sciences. On a model 7,12,17-trioxa[11]helicene molecule, experimental results from multiple spectroscopic techniques are analyzed on the basis of density functional theory (DFT) simulations to test computational methodology and analyze the origins of chirality. Infrared (IR), vibrational circular dichroism (VCD), electronic circular dichroism (ECD), magnetic circular dichroism (MCD), and Raman optical activity (ROA, computations only) spectra are compared. Large dissymmetry factors are predicted both for vibrational (ROA/Raman ∼ VCD/IR ∼ 10-3) and electronic (ECD/Abs ∼10-2) optical activity, which could be verified experimentally except for ROA. Largest VCD signals come from a strong vibrational coupling of the C-H in-plane and out-of-plane bending modes in stacked helicene rings. The sum-over-states (SOS) approach appeared convenient for simulation of MCD spectra. Our results demonstrated that selected computational methods can be successfully used for reliable modeling of spectral and chiroptical properties of large helicenes. In particular, they can be used for guiding rational design of strongly chiral chromophores.
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Affiliation(s)
- Taye B. Demissie
- Institute
of Organic Chemistry and Biochemistry, Academy
of Sciences, Flemingovo
náměstí 2, 16610 Prague, Czech Republic
- Materials
Science Program, Department of Chemistry, Addis Ababa University, P. O. Box 1176, Addis Ababa 1176, Ethiopia
- Department
of Chemistry, University of Botswana, Notwane Rd, P/bag
UB 00704 Gaborone, Botswana
| | - M. Shyam Sundar
- Institute
of Organic Chemistry and Biochemistry, Academy
of Sciences, Flemingovo
náměstí 2, 16610 Prague, Czech Republic
| | - Karthick Thangavel
- Institute
of Organic Chemistry and Biochemistry, Academy
of Sciences, Flemingovo
náměstí 2, 16610 Prague, Czech Republic
- Department
of Physics, School of Electrical and Electronics Engineering, SASTRA Deemed University, Thanjavur, 613 401 Tamil Nadu, India
| | - Valery Andrushchenko
- Institute
of Organic Chemistry and Biochemistry, Academy
of Sciences, Flemingovo
náměstí 2, 16610 Prague, Czech Republic
| | - Ashutosh V. Bedekar
- Department
of Chemistry, Faculty of Science, The Maharaja
Sayajirao University of Baroda, Vadodara 390 002, India
| | - Petr Bouř
- Institute
of Organic Chemistry and Biochemistry, Academy
of Sciences, Flemingovo
náměstí 2, 16610 Prague, Czech Republic
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10
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Wilson AL, Outeiral C, Dowd SE, Doig AJ, Popelier PLA, Waltho JP, Almond A. Deconvolution of conformational exchange from Raman spectra of aqueous RNA nucleosides. Commun Chem 2020; 3:56. [PMID: 36703475 PMCID: PMC9814580 DOI: 10.1038/s42004-020-0298-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 04/06/2020] [Indexed: 01/29/2023] Open
Abstract
Ribonucleic acids (RNAs) are key to the central dogma of molecular biology. While Raman spectroscopy holds great potential for studying RNA conformational dynamics, current computational Raman prediction and assignment methods are limited in terms of system size and inclusion of conformational exchange. Here, a framework is presented that predicts Raman spectra using mixtures of sub-spectra corresponding to major conformers calculated using classical and ab initio molecular dynamics. Experimental optimization allowed purines and pyrimidines to be characterized as predominantly syn and anti, respectively, and ribose into exchange between equivalent south and north populations. These measurements are in excellent agreement with Raman spectroscopy of ribonucleosides, and previous experimental and computational results. This framework provides a measure of ribonucleoside solution populations and conformational exchange in RNA subunits. It complements other experimental techniques and could be extended to other molecules, such as proteins and carbohydrates, enabling biological insights and providing a new analytical tool.
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Affiliation(s)
- Alex L. Wilson
- grid.5379.80000000121662407Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Science, Faculty of Science and Engineering, The University of Manchester, M1 7DN Manchester, UK
| | - Carlos Outeiral
- grid.5379.80000000121662407Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Science, Faculty of Science and Engineering, The University of Manchester, M1 7DN Manchester, UK
| | - Sarah E. Dowd
- grid.5379.80000000121662407Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Science, Faculty of Science and Engineering, The University of Manchester, M1 7DN Manchester, UK
| | - Andrew J. Doig
- grid.5379.80000000121662407Division of Neuroscience and Experimental Psychology, Michael Smith Building, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, M13 9PT Manchester, UK
| | - Paul L. A. Popelier
- grid.5379.80000000121662407Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Science, Faculty of Science and Engineering, The University of Manchester, M1 7DN Manchester, UK
| | - Jonathan P. Waltho
- grid.5379.80000000121662407Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Science, Faculty of Science and Engineering, The University of Manchester, M1 7DN Manchester, UK ,grid.11835.3e0000 0004 1936 9262Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, S10 2TN Sheffield, UK
| | - Andrew Almond
- grid.5379.80000000121662407Manchester Institute of Biotechnology and Department of Chemistry, School of Natural Science, Faculty of Science and Engineering, The University of Manchester, M1 7DN Manchester, UK
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11
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Minguirbara A, Vamhindi BSDR, Koyambo-Konzapa SJ, Nsangou M. Effects of counterions and solvents on the geometrical and vibrational features of dinucleoside-monophosphate (dNMP): case of 3',5'-dideoxycytidine-monophosphate (dDCMP). J Mol Model 2020; 26:99. [PMID: 32285211 DOI: 10.1007/s00894-020-04369-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 03/25/2020] [Indexed: 11/26/2022]
Abstract
The effects of the interaction of the monovalent (Li+, Na+, K+) and divalent (Mg2+) counterions hexahydrated (6H2O), with the PO2- group, on the geometrical and vibrational characteristics of 3', 5'-dDCMP, were studied using the DFT/B3LYP/6-31++G(d) method. These calculations were performed using the explicit (6H2O) and hybrid (6H2O/Continuum) solvation models. The optimizations reveal that in the conformation g-g- and in the explicit model of solvation, the small ions (Li+, Na+) deviate from the bisector plane of the angle O1-P-O2 and the large ions (K+ and Mg2+) remain in this plane, whereas in the hybrid model of solvation, the counterions deviate from this plane. However, when the conformer is g+g+, the monovalent counterions deviate and divide the remainder of the plane regardless of the type of solvation model. In addition, the g-g- conformer is the most stable in the presence of the explicit solvent, while the g+g+ conformer is the most stable in the presence of the hybrid solvent. Finally, the normal modes of the conformers g-g- and g+g+ in the presence of the counterions in the hybrid model show a better agreement with the available experimental data of the DNA forms A, B (g-g-), and Z (g+g+) relatively to the explicit model. This very good agreement is illustrated by the very small deviations ≤ 0.08% (g-g-) and ≤ 0.41% (g+g+) observed between the calculated and experimental data for the PO2- (asymmetric) stretching mode in the presence of the counterion K+ in the hybrid model. Graphical abstract.
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Affiliation(s)
- Alain Minguirbara
- Department of Physics, Faculty of Science, University of Maroua, Maroua, P.O.Box 814, Cameroon
| | | | | | - Mama Nsangou
- CERDISFA, Department of Physics, Higher Teacher's Training College, University of Maroua, Maroua, P.O.Box 46, Cameroon.
- Department of Physics, Faculty of Science, University of Ngaoundere, Ngaoundere, P.O.Box 454, Cameroon.
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12
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Malik C, Kaur N, Singh B, Pandey A. Luminescence properties of tricalcium phosphate doped with dysprosium. Appl Radiat Isot 2020; 158:109062. [PMID: 32174376 DOI: 10.1016/j.apradiso.2020.109062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 01/24/2020] [Accepted: 01/24/2020] [Indexed: 11/30/2022]
Abstract
Tricalcium phosphate having effective atomic number Zeff = 15.785, equivalent to that of bones was studied for its thermoluminescence (TL) and photoluminescence (PL) properties. Different samples with varied concentrations of the dopant Dy3+ (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mol %) were synthesized by the chemical co-precipitation technique. Phase and compound confirmations were done using X-Ray Diffraction (XRD) and the phosphors' crystallite size was calculated using Scherrer's formula which was found to range between 27 nm and 49 nm. The surface morphological study was done using Field Emission-Scanning Electron Microscopy (FE-SEM). Other characterization techniques used for compound confirmation included Energy Dispersive X-Ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FTIR). Samples were further irradiated by gamma rays (emitted from Co-60) with dose varying from 10 Gy to 5 kGy in order to study their TL properties. Concentration optimization of the given phosphor was done in terms of its TL intensity and was found to be 0.5 mol %. The TL dose response of the phosphor was linear over a wide range of dose (10 Gy-3 kGy). Deconvolution was performed on the glow curve for 10 Gy dose, giving six peaks (at 127o, 153o, 185o, 218o, 313o and 335oC) suggesting the presence of six different types of traps. Other characteristics of the TL material i.e. repeatability and fading were also studied. Overall, the phosphor showed promising results for its utility in TL dosimetry. In addition to the TL, PL further confirmed the presence of dopant in the phosphor. Moreover, the dopant concentration was optimized in terms of the nanophosphor's PL intensity. The Commission International de l'Éclairage (CIE) was used to calculate chromaticity coordinates, colour rendering index and colour temperature in order to investigate the phosphor's application in white LEDs.
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Affiliation(s)
- Chirag Malik
- Department of Physics & Astrophysics, University of Delhi, New Delhi, 110007, India
| | - Najdeep Kaur
- Department of Physics, Sri Venkateswara College, University of Delhi, Benito Juarez Road, Dhaula Kuan, New Delhi, 110021, India
| | - Birendra Singh
- Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Anant Pandey
- Department of Physics, Sri Venkateswara College, University of Delhi, Benito Juarez Road, Dhaula Kuan, New Delhi, 110021, India.
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13
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Krupová M, Kessler J, Bouř P. Recent Trends in Chiroptical Spectroscopy: Theory and Applications of Vibrational Circular Dichroism and Raman Optical Activity. Chempluschem 2020; 85:561-575. [DOI: 10.1002/cplu.202000014] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/18/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Monika Krupová
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Faculty of Mathematics and PhysicsCharles University Ke Karlovu 3 12116 Prague 2 Czech Republic
| | - Jiří Kessler
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
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14
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Andrushchenko V, Pohle W. Influence of the hydrophobic domain on the self-assembly and hydrogen bonding of hydroxy-amphiphiles. Phys Chem Chem Phys 2019; 21:11242-11258. [PMID: 31099371 DOI: 10.1039/c9cp01475f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The amphiphiles 1-octadecanol (octadecyl (stearyl) alcohol, ODA) and 1,2-dioleoylglycerol (DOG) were studied by IR spectroscopy and X-ray diffraction combined with multiscale theoretical modeling. The computations allowed us to rationalize the experimental findings and deduce the supramolecular structure of the formed assemblies while providing a fairly detailed insight into their hydrogen-bonding patterns. IR spectra revealed that the amphiphilic assemblies dramatically differ in structural order and hydrogen-bond strength, both being high in ODA and low in DOG. On the other hand, both compounds demonstrated common features, namely a splitting of the IR bands arising from O-H stretching vibrations (νOH) as well as complete hydrophobicity. However, the observed phenomena have different origins in the two amphiphiles. While the νOH split in ODA occurs due to a vibrational coupling along the string of inter-layer O-HO hydrogen bonds, in DOG it arises from different types of hydrogen bonds (intra- and intermolecular). The hydrophobicity of ODA stems from the very tight O-HO hydrogen bonding network connecting the opposite monolayers in a densely packed tilted crystalline phase (Lc'), whereas in DOG it occurs because the polar sites are locked inside reverted micellar-like assemblies. ODA and DOG illustrate that, in the assemblies of amphiphilic hydroxyl compounds, hydrogen bonds can be formed in a wide structural latitude, which is primarily governed by the chemical nature of apolar chains. Such a wide structural variability of OH-involving hydrogen bonds can be essential for the biological functioning of relevant molecules, such as glycolipids, acylglycerols, and, potentially, glycoproteins and carbohydrates.
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Affiliation(s)
- Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic.
| | - Walter Pohle
- Center for Molecular Biomedicine, Department of Biophysics, Friedrich Schiller University Jena, Hans-Knöll-Str. 2, 07745 Jena, Germany.
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15
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Ghidinelli S, Abbate S, Boiadjiev SE, Lightner DA, Longhi G. l-Stercobilin-HCl and d-Urobilin-HCl. Analysis of Their Chiroptical and Conformational Properties by VCD, ECD, and CPL Experiments and MD and DFT Calculations. J Phys Chem B 2018; 122:12351-12362. [DOI: 10.1021/acs.jpcb.8b07954] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Simone Ghidinelli
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Sergio Abbate
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy
| | - Stefan E. Boiadjiev
- Department of Chemistry and Biochemistry, Medical University-Pleven, 1 St. Kl. Ohridski Str., 5800 Pleven, Bulgaria
| | - David A. Lightner
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, 89557-0020 Nevada, United States
| | - Giovanna Longhi
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Viale Europa 11, 25123 Brescia, Italy
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16
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Kessler J, Andrushchenko V, Kapitán J, Bouř P. Insight into vibrational circular dichroism of proteins by density functional modeling. Phys Chem Chem Phys 2018; 20:4926-4935. [PMID: 29384537 DOI: 10.1039/c7cp08016f] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Vibrational circular dichroism (VCD) spectroscopy is an excellent method to determine the secondary structure of proteins in solution. Comparison of experimental spectra with quantum-chemical simulations represents a convenient and objective way to extract information on the structure. This has been difficult for such large molecules where approximate theoretical models have to be used. In the present study we applied the Cartesian-coordinate based tensor transfer (CCT) making it possible to extend the density functional theory (DFT) and model spectral intensities of large globular proteins nearly at quantum-chemical precision. Indeed, comparison with experiment provided a better understanding of the dependence of VCD spectral shapes on the geometry, their sensitivity to fine structural details and interactions with the environment. On a model set of globular proteins the simulated spectra correlated well with experimental data and revealed which structural information can (and cannot) be obtained from this kind of spectroscopy. Although the VCD technique has been regarded as being rather insensitive to side-chain variations, we found that the spectra of human and hen lysozyme differing by a few amino acids only are quite distinct. This has been explained by long-distance coupling of the amide vibrations. Likewise, the modeling reproduced some spectral changes caused by protein deuteration even when the protein structure was conserved.
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Affiliation(s)
- Jiří Kessler
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague, Czech Republic.
| | - Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague, Czech Republic.
| | - Josef Kapitán
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague, Czech Republic.
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17
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Lemelin V, Bass AD, Wagner JR, Sanche L. Absolute vibrational excitation cross sections for 1-18 eV electron scattering from condensed dimethyl phosphate (DMP). J Chem Phys 2017; 147:234305. [DOI: 10.1063/1.5008486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- V. Lemelin
- Groupe en Sciences des Radiations, Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et Sciences des Radiations, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - A. D. Bass
- Groupe en Sciences des Radiations, Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et Sciences des Radiations, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - J. R. Wagner
- Groupe en Sciences des Radiations, Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et Sciences des Radiations, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - L. Sanche
- Groupe en Sciences des Radiations, Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et Sciences des Radiations, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
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18
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Fingerhut BP, Costard R, Elsaesser T. Predominance of short range Coulomb forces in phosphate-water interactions—a theoretical analysis. J Chem Phys 2016. [DOI: 10.1063/1.4962755] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Benjamin P. Fingerhut
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - Rene Costard
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
| | - Thomas Elsaesser
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany
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