1
|
Kaur R, Nikkel DJ, Wetmore SD. Computational studies of DNA repair: Insights into the function of monofunctional DNA glycosylases in the base excision repair pathway. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2020. [DOI: 10.1002/wcms.1471] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Rajwinder Kaur
- Department of Chemistry and Biochemistry University of Lethbridge Lethbridge Alberta Canada
| | - Dylan J. Nikkel
- Department of Chemistry and Biochemistry University of Lethbridge Lethbridge Alberta Canada
| | - Stacey D. Wetmore
- Department of Chemistry and Biochemistry University of Lethbridge Lethbridge Alberta Canada
| |
Collapse
|
2
|
Aydinoglu S, Pasti A, Biver T, Mennucci B. Auramine O interaction with DNA: a combined spectroscopic and TD-DFT analysis. Phys Chem Chem Phys 2019; 21:20606-20612. [DOI: 10.1039/c9cp03071a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
AuO fluorescent molecular rotor intercalation into DNA: calculations and experiments uncover binding details as absorbance/fluorescence features, energies involved and geometries.
Collapse
Affiliation(s)
- Sabriye Aydinoglu
- Department of Analytical Chemistry
- Faculty of Pharmacy – Cukurova University
- 01250 Sarıçam/Adana
- Turkey
| | - Andrea Pasti
- Department of Chemistry and Industrial Chemistry
- University of Pisa
- 56124 Pisa
- Italy
| | - Tarita Biver
- Department of Analytical Chemistry
- Faculty of Pharmacy – Cukurova University
- 01250 Sarıçam/Adana
- Turkey
- Department of Pharmacy
| | - Benedetta Mennucci
- Department of Chemistry and Industrial Chemistry
- University of Pisa
- 56124 Pisa
- Italy
| |
Collapse
|
3
|
Saranya V, Shankar R, Vijayakumar S. Structural exploration of viral matrix protein 40 interaction with the transition metal ions (Ag+ and Cu2+). J Biomol Struct Dyn 2018; 37:2875-2896. [DOI: 10.1080/07391102.2018.1498803] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- V. Saranya
- Department of Physics, Bharathiar University, Coimbatore, India
| | - R. Shankar
- Department of Physics, Bharathiar University, Coimbatore, India
| | - S. Vijayakumar
- Department of Medical Physics, Bharathiar University, Coimbatore, India
| |
Collapse
|
4
|
Radhika R, Shankar R, Vijayakumar S, Kolandaivel P. Role of 6-Mercaptopurine in the potential therapeutic targets DNA base pairs and G-quadruplex DNA: insights from quantum chemical and molecular dynamics simulations. J Biomol Struct Dyn 2017; 36:1369-1401. [PMID: 28436311 DOI: 10.1080/07391102.2017.1323013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The theoretical studies on DNA with the anticancer drug 6-Mercaptopurine (6-MP) are investigated using theoretical methods to shed light on drug designing. Among the DNA base pairs considered, 6-MP is stacked with GC with the highest interaction energy of -46.19 kcal/mol. Structural parameters revealed that structure of the DNA base pairs is deviated from the planarity of the equilibrium position due to the formation of hydrogen bonds and stacking interactions with 6-MP. These deviations are verified through the systematic comparison between X-H bond contraction and elongation and the associated blue shift and red shift values by both NBO analysis and vibrational analysis. Bent's rule is verified for the C-H bond contraction in the 6-MP interacted base pairs. The AIM results disclose that the higher values of electron density (ρ) and Laplacian of electron density (∇2ρ) indicate the increased overlap between the orbitals that represent the strong interaction and positive values of the total electron density show the closed-shell interaction. The relative sensitivity of the chemical shift values for the DNA base pairs with 6-MP is investigated to confirm the hydrogen bond strength. Molecular dynamics simulation studies of G-quadruplex DNA d(TGGGGT)4 with 6-MP revealed that the incorporation of 6-MP appears to cause local distortions and destabilize the G-quadruplex DNA.
Collapse
Affiliation(s)
- R Radhika
- a Department of Physics , Bharathiar University , Coimbatore , India
| | - R Shankar
- a Department of Physics , Bharathiar University , Coimbatore , India
| | - S Vijayakumar
- b Department of Medical Physics , Bharathiar University , Coimbatore , India
| | - P Kolandaivel
- a Department of Physics , Bharathiar University , Coimbatore , India
| |
Collapse
|
5
|
Skúpa K, Urban J. Modifications of the chromophore of Spinach aptamer based on QM:MM calculations. J Mol Model 2017; 23:46. [PMID: 28154983 DOI: 10.1007/s00894-017-3232-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/13/2017] [Indexed: 10/20/2022]
Abstract
Spinach aptamer was developed as an RNA analog of the green fluorescent protein. The aptamer interacts with its ligand and modifies its electronic spectrum so that it fluoresces brightly at the wavelength of 501 nm. Song et al. investigated modifications of the ligand in their experimental study and found a molecule emitting at 523 nm upon creating a complex with the Spinach aptamer. The crystal structure of the aptamer in complex with its original ligand has been published, which enabled us to study the system computationally. In this article, we suggest several new modifications of the ligand that shift the emission maximum of the complex to even longer wavelengths. Our results are based on combined quantum mechanical/molecular mechanical calculations with DFT method used for geometry optimization and TD-DFT for calculations of absorption and emission energies.
Collapse
Affiliation(s)
- Katarína Skúpa
- Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Bratislava, Slovakia.
| | - Ján Urban
- Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Bratislava, Slovakia
| |
Collapse
|
6
|
Chehel Amirani M, Tang T. A QM:MM model for the interaction of DNA nucleotides with carbon nanotubes. Phys Chem Chem Phys 2015; 17:7564-75. [PMID: 25708519 DOI: 10.1039/c4cp05222f] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hybrid materials formed by DNA and carbon nanotubes (CNTs) have shown very interesting properties, but their simulation in solution using quantum mechanical approaches is still a challenge in the computational chemistry community. In this paper, we developed a QM:MM model to study the interactions between charged DNA nucleotides and carbon nanotubes in solution. All four types of DNA nucleotides were taken to interact with two CNTs of similar diameter but different chiralities: (4,4) and (7,0). The nucleotides and CNTs were treated at the QM level, while added water and neutralizing ions were modeled at the MM level. ONIOM simulations were performed at the (M06-2X/6-31G(d):Amber) level for the hybrids, as well as for individually solvated CNTs and nucleotides, which allowed us to evaluate the energy of binding. Our binding energy (BE) values range from 146.60 to 503.43 kJ mol(-1), indicating strong physisorption of nucleotides on CNTs. The relatively large BE, compared with past studies on nucleobase-CNT binding in a vacuum, could be due to the larger size of nucleotides compared with nucleobases, the charges on the nucleotides, and the inclusion of solution which causes the release of water molecules upon hybridization.
Collapse
|
7
|
An Y, Bloom JWG, Wheeler SE. Quantifying the π-Stacking Interactions in Nitroarene Binding Sites of Proteins. J Phys Chem B 2015; 119:14441-50. [DOI: 10.1021/acs.jpcb.5b08126] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Yi An
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Jacob W. G. Bloom
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| | - Steven E. Wheeler
- Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States
| |
Collapse
|
8
|
Bigler DJ, Peterson LW, Cafiero M. DFT and MP2 study of the effects of mutations on the binding of ligands within the SULT1A3 active site. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
9
|
Chung LW, Sameera WMC, Ramozzi R, Page AJ, Hatanaka M, Petrova GP, Harris TV, Li X, Ke Z, Liu F, Li HB, Ding L, Morokuma K. The ONIOM Method and Its Applications. Chem Rev 2015; 115:5678-796. [PMID: 25853797 DOI: 10.1021/cr5004419] [Citation(s) in RCA: 738] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Lung Wa Chung
- †Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China
| | - W M C Sameera
- ‡Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano Nishihiraki-cho, Sakyo, Kyoto 606-8103, Japan
| | - Romain Ramozzi
- ‡Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano Nishihiraki-cho, Sakyo, Kyoto 606-8103, Japan
| | - Alister J Page
- §Newcastle Institute for Energy and Resources, The University of Newcastle, Callaghan 2308, Australia
| | - Miho Hatanaka
- ‡Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano Nishihiraki-cho, Sakyo, Kyoto 606-8103, Japan
| | - Galina P Petrova
- ∥Faculty of Chemistry and Pharmacy, University of Sofia, Bulgaria Boulevard James Bourchier 1, 1164 Sofia, Bulgaria
| | - Travis V Harris
- ‡Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano Nishihiraki-cho, Sakyo, Kyoto 606-8103, Japan.,⊥Department of Chemistry, State University of New York at Oswego, Oswego, New York 13126, United States
| | - Xin Li
- #State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Zhuofeng Ke
- ∇School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Fengyi Liu
- ○Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Hai-Bei Li
- ■School of Ocean, Shandong University, Weihai 264209, China
| | - Lina Ding
- ▲School of Pharmaceutical Sciences, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan 450001, China
| | - Keiji Morokuma
- ‡Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano Nishihiraki-cho, Sakyo, Kyoto 606-8103, Japan
| |
Collapse
|
10
|
Wilson KA, Wetmore SD. A Survey of DNA–Protein π–Interactions: A Comparison of Natural Occurrences and Structures, and Computationally Predicted Structures and Strengths. CHALLENGES AND ADVANCES IN COMPUTATIONAL CHEMISTRY AND PHYSICS 2015. [DOI: 10.1007/978-3-319-14163-3_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
|
11
|
Hussain HB, Wilson KA, Wetmore SD. Serine and Cysteine π-Interactions in Nature: A Comparison of the Frequency, Structure, and Stability of Contacts Involving Oxygen and Sulfur. Aust J Chem 2015. [DOI: 10.1071/ch14598] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Despite many DNA–protein π-interactions in high-resolution crystal structures, only four X–H···π or X···π interactions were found between serine (Ser) or cysteine (Cys) and DNA nucleobase π-systems in over 100 DNA–protein complexes (where X = O for Ser and X = S for Cys). Nevertheless, 126 non-covalent contacts occur between Ser or Cys and the aromatic amino acids in many binding arrangements within proteins. Furthermore, Ser and Cys protein–protein π-interactions occur with similar frequencies and strengths. Most importantly, due to the great stability that can be provided to biological macromolecules (up to –20 kJ mol–1 for neutral π-systems or –40 kJ mol–1 for cationic π-systems), Ser and Cys π-interactions should be considered when analyzing protein stability and function.
Collapse
|
12
|
Chehel Amirani M, Tang T. Binding of nucleobases with graphene and carbon nanotube: a review of computational studies. J Biomol Struct Dyn 2014; 33:1567-97. [DOI: 10.1080/07391102.2014.954315] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
13
|
Wilson KA, Kellie JL, Wetmore SD. DNA-protein π-interactions in nature: abundance, structure, composition and strength of contacts between aromatic amino acids and DNA nucleobases or deoxyribose sugar. Nucleic Acids Res 2014; 42:6726-41. [PMID: 24744240 PMCID: PMC4041443 DOI: 10.1093/nar/gku269] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Four hundred twenty-eight high-resolution DNA-protein complexes were chosen for a bioinformatics study. Although 164 crystal structures (38% of those searched) contained no interactions, 574 discrete π-contacts between the aromatic amino acids and the DNA nucleobases or deoxyribose were identified using strict criteria, including visual inspection. The abundance and structure of the interactions were determined by unequivocally classifying the contacts as either π-π stacking, π-π T-shaped or sugar-π contacts. Three hundred forty-four nucleobase-amino acid π-π contacts (60% of all interactions identified) were identified in 175 of the crystal structures searched. Unprecedented in the literature, 230 DNA-protein sugar-π contacts (40% of all interactions identified) were identified in 137 crystal structures, which involve C-H···π and/or lone-pair···π interactions, contain any amino acid and can be classified according to sugar atoms involved. Both π-π and sugar-π interactions display a range of relative monomer orientations and therefore interaction energies (up to -50 (-70) kJ mol(-1) for neutral (charged) interactions as determined using quantum chemical calculations). In general, DNA-protein π-interactions are more prevalent than perhaps currently accepted and the role of such interactions in many biological processes may yet to be uncovered.
Collapse
Affiliation(s)
- Katie A Wilson
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, AB, T1K 3M4, Canada
| | - Jennifer L Kellie
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, AB, T1K 3M4, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, AB, T1K 3M4, Canada
| |
Collapse
|
14
|
An Y, Raju RK, Lu T, Wheeler SE. Aromatic interactions modulate the 5'-base selectivity of the DNA-binding autoantibody ED-10. J Phys Chem B 2014; 118:5653-9. [PMID: 24802982 DOI: 10.1021/jp502069a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present detailed computational analyses of the binding of four dinucleotides to a highly sequence-selective single-stranded DNA (ssDNA) binding antibody (ED-10) and selected point mutants. Anti-DNA antibodies are central to the pathogenesis of systemic lupus erythematosus (SLE), and a more complete understanding of the mode of binding of DNA and other ligands will be necessary to elucidate the role of anti-DNA antibodies in the kidney inflammation associated with SLE. Classical molecular mechanics based molecular dynamics simulations and density functional theory (DFT) computations were applied to pinpoint the origin of selectivity for the 5'-nucleotide. In particular, the strength of interactions between each nucleotide and the surrounding residues were computed using MMGBSA as well as DFT applied to a cluster model of the binding site. The results agree qualitatively with experimental binding free energies, and indicate that π-stacking, CH/π, NH/π, and hydrogen-bonding interactions all contribute to 5'-base selectivity in ED-10. Most importantly, the selectivity for dTdC over dAdC arises primarily from differences in the strength of π-stacking and XH/π interactions with the surrounding aromatic residues; hydrogen bonds play little role. These data suggest that a key Tyr residue, which is not present in other anti-DNA antibodies, plays a key role in the 5'-base selectivity, while we predict that the mutation of a single Trp residue can tune the selectivity for dTdC over dAdC.
Collapse
Affiliation(s)
- Yi An
- Department of Chemistry, Texas A&M University , College Station, Texas 77843, United States
| | | | | | | |
Collapse
|
15
|
Schmidt TC, Paasche A, Grebner C, Ansorg K, Becker J, Lee W, Engels B. QM/MM investigations of organic chemistry oriented questions. Top Curr Chem (Cham) 2014; 351:25-101. [PMID: 22392477 DOI: 10.1007/128_2011_309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
About 35 years after its first suggestion, QM/MM became the standard theoretical approach to investigate enzymatic structures and processes. The success is due to the ability of QM/MM to provide an accurate atomistic picture of enzymes and related processes. This picture can even be turned into a movie if nuclei-dynamics is taken into account to describe enzymatic processes. In the field of organic chemistry, QM/MM methods are used to a much lesser extent although almost all relevant processes happen in condensed matter or are influenced by complicated interactions between substrate and catalyst. There is less importance for theoretical organic chemistry since the influence of nonpolar solvents is rather weak and the effect of polar solvents can often be accurately described by continuum approaches. Catalytic processes (homogeneous and heterogeneous) can often be reduced to truncated model systems, which are so small that pure quantum-mechanical approaches can be employed. However, since QM/MM becomes more and more efficient due to the success in software and hardware developments, it is more and more used in theoretical organic chemistry to study effects which result from the molecular nature of the environment. It is shown by many examples discussed in this review that the influence can be tremendous, even for nonpolar reactions. The importance of environmental effects in theoretical spectroscopy was already known. Due to its benefits, QM/MM can be expected to experience ongoing growth for the next decade.In the present chapter we give an overview of QM/MM developments and their importance in theoretical organic chemistry, and review applications which give impressions of the possibilities and the importance of the relevant effects. Since there is already a bunch of excellent reviews dealing with QM/MM, we will discuss fundamental ingredients and developments of QM/MM very briefly with a focus on very recent progress. For the applications we follow a similar strategy.
Collapse
Affiliation(s)
- Thomas C Schmidt
- Institut für Phys. und Theor. Chemie, Emil-Fischer-Strasse 42, Campus Hubland Nord, 97074, Würzburg, Germany
| | | | | | | | | | | | | |
Collapse
|
16
|
Copeland KL, Pellock SJ, Cox JR, Cafiero ML, Tschumper GS. Examination of tyrosine/adenine stacking interactions in protein complexes. J Phys Chem B 2013; 117:14001-8. [PMID: 24171662 DOI: 10.1021/jp408027j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The π-stacking interactions between tyrosine amino acid side chains and adenine-bearing ligands are examined. Crystalline protein structures from the protein data bank (PDB) exhibiting face-to-face tyrosine/adenine arrangements were used to construct 20 unique 4-methylphenol/N9-methyladenine (p-cresol/9MeA) model systems. Full geometry optimization of the 20 crystal structures with the M06-2X density functional theory method identified 11 unique low-energy conformations. CCSD(T) complete basis set (CBS) limit interaction energies were estimated for all of the structures to determine the magnitude of the interaction between the two ring systems. CCSD(T) computations with double-ζ basis sets (e.g., 6-31G*(0.25) and aug-cc-pVDZ) indicate that the MP2 method overbinds by as much as 3.07 kcal mol(-1) for the crystal structures and 3.90 kcal mol(-1) for the optimized structures. In the 20 crystal structures, the estimated CCSD(T) CBS limit interaction energy ranges from -4.00 to -6.83 kcal mol(-1), with an average interaction energy of -5.47 kcal mol(-1), values remarkably similar to the corresponding data for phenylalanine/adenine stacking interactions. Geometry optimization significantly increases the interaction energies of the p-cresol/9MeA model systems. The average estimated CCSD(T) CBS limit interaction energy of the 11 optimized structures is 3.23 kcal mol(-1) larger than that for the 20 crystal structures.
Collapse
Affiliation(s)
- Kari L Copeland
- Department of Chemistry and Biochemistry, University of Mississippi , University, Mississippi 38677, United States
| | | | | | | | | |
Collapse
|
17
|
Wells RA, Kellie JL, Wetmore SD. Significant strength of charged DNA-protein π-π interactions: a preliminary study of cytosine. J Phys Chem B 2013; 117:10462-74. [PMID: 23991905 DOI: 10.1021/jp406829d] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The present work characterized the preferred gas-phase structure and optimum interaction energy of both parallel stacked and perpendicular T-shaped dimers between cytosine (C), as a representative nucleobase, and aspartic/glutamic acid (DE), aspartate/glutamate (DE(-)) or arginine (R(+)), using detailed M06-2X/6-31+G(d,p) potential energy surface scans as a function of the relative monomer orientation. Through comparison to previous literature on the π-π interactions between the DNA nucleobases and the aromatic amino acid residues, this work will allow for comparisons between DNA-protein interactions involving aromatic and acyclic R-side chains, as well as comparisons of the relative geometric dependence and magnitude of π-π (C:DE), πcation-π (C:R(+)), and πanion-π (C:DE(-)) interactions. Our results show that the preferred relative monomer orientation is highly dependent on the monomer composition and charge, and is dictated by electrostatic-driven interactions. More importantly, for the first time, we report that the π-π interactions between cytosine and (neutral) aspartic/glutamic acid are up to approximately -40 kJ mol(-1), while the πcation-π or πanion-π interactions between cytosine and arginine or aspartate/glutamate are up to approximately -90 and -99 kJ mol(-1), respectively. An extensive investigation of the effects of the computational methodology implemented, including comparisons to detailed CCSD(T)/CBS potential energy surfaces and interaction energies, supports the use of M06-2X, as well as ωB97X-D, to study DNA-protein π-π interactions of varying composition and charge. Most importantly, the CCSD(T)/CBS results verify the strong nature of these DNA-protein π-π interactions, as well as the unique nature of the πcation-π and πanion-π counterparts. Therefore, our results emphasize that a wide variety of different types of noncovalent interactions between both cyclic and acyclic π-containing components can significantly contribute to the stability of DNA-protein complexes and likely play a larger role in biology than currently accepted.
Collapse
Affiliation(s)
- Rachael A Wells
- Department of Chemistry and Biochemistry, University of Lethbridge , 4401 University Drive West, Lethbridge, Alberta, Canada T1K 3M4
| | | | | |
Collapse
|
18
|
Biancardi A, Biver T, Secco F, Mennucci B. An investigation of the photophysical properties of minor groove bound and intercalated DAPI through quantum-mechanical and spectroscopic tools. Phys Chem Chem Phys 2013; 15:4596-603. [PMID: 23423468 DOI: 10.1039/c3cp44058c] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fluorescent probe 4',6-diamidino-2-phenylindole (DAPI) is a dye known to interact with polynucleotides in a non-univocal manner, both intercalation and minor groove binding modes being possible, and to specifically change its photophysical properties according to the different environments. To investigate this behavior, quantum-mechanical calculations using time-dependent density functional theory (TDDFT), coupled with polarizable continuum and/or atomistic models, were performed in combination with spectroscopic measurements of the probe in the different environments, ranging from a homogeneous solution to the minor groove or intercalation pockets of double stranded nucleic acids. According to our simulation, the electronic transition involves a displacement of the electron charge towards the external amidine groups and this feature makes the absorption energies very environment-sensitive while a much smaller sensitivity is seen in the fluorescence energies. Moreover, the calculations show that the DAPI molecule, when minor groove bound to the nucleic acid, presents both a reduced geometrical flexibility because of the rigid DNA pocket and a reduced polarization due to the very "apolar" microenvironment. All these effects can be used to better understand the observed enhancement of the fluorescence, which makes it an excellent marker for DNA.
Collapse
Affiliation(s)
- Alessandro Biancardi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento, 35-56126 Pisa, Italy.
| | | | | | | |
Collapse
|
19
|
Kellie JL, Wetmore SD. Selecting DFT methods for use in optimizations of enzyme active sites: applications to ONIOM treatments of DNA glycosylases. CAN J CHEM 2013. [DOI: 10.1139/cjc-2012-0506] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
When using a hybrid methodology to treat an enzymatic reaction, many factors contribute to selecting the method for the high-level region, which can be complicated by the presence of dispersion-driven interactions such as π–π stacking. In addition, the proper treatment of the reaction center often requires a large number of heavy atoms to be included in the high-level region, precluding the use of ab initio methods such as MP2 as well as large basis sets, in the optimization step. In the present work, popular DFT methods were tested to identify an appropriate functional for treating the high-level region in ONIOM optimizations of reactions catalyzed by nonmetalloenzymes. Eight different DFT methods (B3LYP, B97-2, MPW1K, MPWB1K, BB1K, B1B95, M06-2X, and ωB97X-D) in combination with four double-ζ quality Pople basis sets were tested for their ability to optimize noncovalent interactions (hydrogen bonding and π–π) and characterize reactions (proton transfer, SN2 hydrolysis, and unimolecular cleavage). Although the primary focus of this study is accurate structure determination, energetics were also examined at both the optimization level of theory, and with triple-ζ quality basis set and select (M06-2X or ωB97X-D) methods. If dispersion-driven interactions exist within the active site, then MPWB1K/6-31G(d,p) or M06-2X/6-31+G(d,p) are recommended for the optimization step with subsequent triple-ζ quality single-point energies. However, since dispersion-corrected functionals (M06-2X and ωB97X-D) generally require diffuse functions to yield appropriate geometries, the possible size of the high-level region is greatly limited with these methods. In contrast, if the model is large enough to recover steric constraints on π–π interactions, then B3LYP with a small basis set performs comparatively well for the optimization step and is significantly less computationally expensive. Interestingly, the functionals that afford the best geometries often do not yield the best energetics, which emphasizes the importance of structural benchmark studies.
Collapse
Affiliation(s)
- Jennifer L. Kellie
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K 3M4, Canada
| | - Stacey D. Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K 3M4, Canada
| |
Collapse
|
20
|
Mládek A, Krepl M, Svozil D, Čech P, Otyepka M, Banáš P, Zgarbová M, Jurečka P, Šponer J. Benchmark quantum-chemical calculations on a complete set of rotameric families of the DNA sugar–phosphate backbone and their comparison with modern density functional theory. Phys Chem Chem Phys 2013; 15:7295-310. [DOI: 10.1039/c3cp44383c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
21
|
KOLB BRIAN, THONHAUSER T. MOLECULAR BIOLOGY AT THE QUANTUM LEVEL: CAN MODERN DENSITY FUNCTIONAL THEORY FORGE THE PATH? ACTA ACUST UNITED AC 2012. [DOI: 10.1142/s1793984412300063] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Recent years have seen vast improvements in the ability of rigorous quantum-mechanical methods to treat systems of interest to molecular biology. In this review article, we survey common computational methods used to study such large, weakly bound systems, starting from classical simulations and reaching to quantum chemistry and density functional theory. We sketch their underlying frameworks and investigate their strengths and weaknesses when applied to potentially large biomolecules. In particular, density functional theory — a framework that can treat thousands of atoms on firm theoretical ground — can now accurately describe systems dominated by weak van der Waals interactions. This newfound ability has rekindled interest in using this tried-and-true approach to investigate biological systems of real importance. In this review, we focus on some new methods within the density functional theory that allow for accurate inclusion of the weak interactions that dominate binding in biological macromolecules. Recent work utilizing these methods to study biologically relevant systems will be highlighted, and a vision for the future of density functional theory within molecular biology will be discussed.
Collapse
Affiliation(s)
- BRIAN KOLB
- Department of Physics, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
| | - T. THONHAUSER
- Department of Physics, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
| |
Collapse
|
22
|
Biancardi A, Cammi R, Cappelli C, Mennucci B, Tomasi J. Modelling vibrational coupling in DNA oligomers: a computational strategy combining QM and continuum solvation models. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1157-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
23
|
Rutledge LR, Wetmore SD. A computational proposal for the experimentally observed discriminatory behavior of hypoxanthine, a weak universal nucleobase. Phys Chem Chem Phys 2012; 14:2743-53. [PMID: 22270716 DOI: 10.1039/c2cp23600a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A computational model composed of six nucleobases was used to investigate why hypoxanthine does not yield duplexes of equal stability when paired opposite each of the natural DNA nucleobases. The magnitudes of all nearest-neighbor interactions in a DNA helix were calculated, including hydrogen-bonding, intra- and interstrand stacking interactions, as well as 1-3 intrastrand stacking interactions. Although the stacking interactions in DNA relevant arrangements are significant and account for at least one third of the total stabilization energy in our nucleobase complexes, the trends in the magnitude of the stacking interactions cannot explain the relative experimental melting temperatures previously reported in the literature. Furthermore, although the total hydrogen-bonding interactions explain why hypoxanthine preferentially pairs with cytosine, the experimental trend for the remaining nucleobases (A, T, G) is not explained. In fact, the calculated pairing preference of hypoxanthine matches that determined experimentally only when the sum of all types of nearest-neighbor interactions is considered. This finding highlights a strong correlation between the relative magnitude of the total nucleobase-nucleobase interactions and measured melting temperatures for DNA strands containing hypoxanthine despite the potential role of other factors (including hydration, temperature, sugar-phosphate backbone). By considering a large range of sequence combinations, we reveal that the binding preference of hypoxanthine is strongly dependent on the nucleobase sequence, which may explain the varied ability of hypoxanthine to universally bind to the natural bases. As a result, we propose that future work should closely examine the interplay between the dominant nucleobase-nucleobase interactions and the overall strand stability to fully understand how sequence context affects the universal binding properties of modified bases and to aid the design of new molecules with ambiguous pairing properties.
Collapse
Affiliation(s)
- Lesley R Rutledge
- Department of Chemistry & Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, Canada T1K 3M4
| | | |
Collapse
|
24
|
Churchill CDM, Eriksson LA, Wetmore SD. Formation mechanism and structure of a guanine-uracil DNA intrastrand cross-link. Chem Res Toxicol 2011; 24:2189-99. [PMID: 22060045 DOI: 10.1021/tx2003239] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The formation and structure of the 5'-G[8-5]U-3' intrastrand cross-link are studied using density functional theory and molecular dynamics simulations due to the potential role of this lesion in the activity of 5-halouracils in antitumor therapies. Upon UV irradiation of 5-halouracil-containing DNA, a guanine radical cation reacts with the uracil radical to form the cross-link, which involves phosphorescence or an intersystem crossing and a rate-determining step of bond formation. Following ionizing radiation, guanine and the uracil radical react, with a rate-limiting step involving hydrogen atom removal. Although cross-link formation from UV radiation is favored, comparison of calculated reaction thermokinetics with that for related experimentally observed purine-pyrimidine cross-links suggests this lesion is also likely to form from ionizing radiation. For the first time, the structure of 5'-G[8-5]U-3' within DNA is identified by molecular dynamics simulations. Furthermore, three conformations of cross-linked DNA are revealed, which differ in the configuration of the complementary bases. Distortions, such as unwinding, are localized to the cross-linked dinucleotide and complementary nucleotides, with minimal changes to the flanking bases. Global changes to the helix, such as bending and groove alterations, parallel cisplatin-induced distortions, which indicate 5'-G[8-5]U-3', may contribute to the cytotoxicity of halouracils in tumor cell DNA using similar mechanisms.
Collapse
Affiliation(s)
- Cassandra D M Churchill
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, Canada T1K 3M4
| | | | | |
Collapse
|
25
|
Rutledge LR, Wetmore SD. Modeling the chemical step utilized by human alkyladenine DNA glycosylase: a concerted mechanism AIDS in selectively excising damaged purines. J Am Chem Soc 2011; 133:16258-69. [PMID: 21877721 DOI: 10.1021/ja207181c] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Human alkyladenine DNA glycosylase (AAG) initiates the repair of a wide variety of (neutral or cationic) alkylated and deaminated purines by flipping damaged nucleotides out of the DNA helix and catalyzing the hydrolytic N-glycosidic bond cleavage. Unfortunately, the limited number of studies on the catalytic pathway has left many unanswered questions about the hydrolysis mechanism. Therefore, detailed ONIOM(M06-2X/6-31G(d):AMBER) reaction potential energy surface scans are used to gain the first atomistic perspective of the repair pathway used by AAG. The lowest barrier for neutral 1,N(6)-ethenoadenine (εA) and cationic N(3)-methyladenine (3MeA) excision corresponds to a concerted (A(N)D(N)) mechanism, where our calculated ΔG(‡) = 87.3 kJ mol(-1) for εA cleavage is consistent with recent kinetic data. The use of a concerted mechanism supports previous speculations that AAG uses a nonspecific strategy to excise both neutral (εA) and cationic (3MeA) lesions. We find that AAG uses nonspecific active site DNA-protein π-π interactions to catalyze the removal of inherently more difficult to excise neutral lesions, and strongly bind to cationic lesions, which comes at the expense of raising the excision barrier for cationic substrates. Although proton transfer from the recently proposed general acid (protein-bound water) to neutral substrates does not occur, hydrogen-bond donation lowers the catalytic barrier, which clarifies the role of a general acid in the excision of neutral lesions. Finally, our work shows that the natural base adenine (A) is further inserted into the AAG active site than the damaged substrates, which results in the loss of a hydrogen bond with Y127 and misaligns the general base (E125) and water nucleophile to lead to poor nucleophile activation. Therefore, our work proposes how AAG discriminates against the natural purines in the chemical step and may also explain why some damaged pyrimidines are bound but are not excised by this enzyme.
Collapse
Affiliation(s)
- Lesley R Rutledge
- Department of Chemistry and Biochemistry, University of Lethbridge, Alberta T1K 3M4, Canada
| | | |
Collapse
|
26
|
Leavens FMV, Churchill CDM, Wang S, Wetmore SD. Evaluating how discrete water molecules affect protein-DNA π-π and π(+)-π stacking and T-shaped interactions: the case of histidine-adenine dimers. J Phys Chem B 2011; 115:10990-1003. [PMID: 21809837 DOI: 10.1021/jp205424z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Changes in the magnitude of (M06-2X/6-31+G(d,p)) π-π stacking and T-shaped (nucleobase-edge and amino acid-edge) interactions between (neutral or protonated) histidine (His) and adenine (A) dimers upon microsolvation with up to four discrete water molecules were determined. A variety of histidine-water interactions were considered including conventional (N-H···O, N···H-O, C-H···O) hydrogen bonding and nonconventional (X-H···π (neutral His) or lone-pair···π (protonated His)) contacts. Overall, the effects of discrete His-H(2)O interactions on the neutral histidine-adenine π-π contacts are negligible (<3 kJ mol(-1) or 15%) regardless of the type of water binding, the number of water molecules bound, or the His-A dimer (stacked or (amino acid- or nucleobase-edge) T-shaped) configuration. This suggests that previously reported gas-phase binding strengths for a variety of neutral amino acid-nucleobase dimers are likely relevant for a wide variety of (microsolvated) environments. In contrast, the presence of water decreases the histidine-adenine π(+)-π interaction by up to 15 kJ mol(-1) (or 30%) for all water binding modes and orientations, as well as different stacked and T-shaped His(+)-A dimers. Regardless of the larger effect of discrete histidine-water interactions on the magnitude of the π(+)-π compared with π-π interactions, the π(+)-π binding strengths remain substantially larger than the corresponding π-π contacts. These findings emphasize the distinct nature of π(+)-π and π-π interactions and suggest that π(+)-π contacts can provide significant stabilization in biological systems relative to π-π contacts under many different environmental conditions.
Collapse
Affiliation(s)
- Fern M V Leavens
- Department of Chemistry & Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, Canada, T1K 3M4
| | | | | | | |
Collapse
|
27
|
Churchill CDM, Wetmore SD. Developing a computational model that accurately reproduces the structural features of a dinucleoside monophosphate unit within B-DNA. Phys Chem Chem Phys 2011; 13:16373-83. [PMID: 21842033 DOI: 10.1039/c1cp21689a] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The ability of a dinucleoside monophosphate to mimic the conformation of B-DNA was tested using a combination of different phosphate models (anionic, neutral, counterion), environments (gas, water), and density functionals (B3LYP, MPWB1K, M06-2X) with the 6-31G(d,p) basis set. Three sequences (5'-GX(Py)-3', where X(Py) = T, U or (Br)U) were considered, which vary in the (natural or modified) 3' pyrimidine nucleobase (X(Py)). These bases were selected due to their presence in natural DNA, structural similarity to T and/or applications in radical-initiated anti-tumour therapies. The accuracy of each of the 54 model, method and sequence combinations was judged based on the ability to reproduce key structural features of natural B-DNA, including the stacked base-base orientation and important backbone torsion angles. B3LYP yields distorted or tilted relative base-base orientations, while many computational challenges were encountered for MPWB1K. Despite wide use in computational studies of DNA, the neutral (protonated) phosphate model could not consistently predict a stacked arrangement for all sequences. In contrast, stacked base-base arrangements were obtained for all sequences with M06-2X in conjunction with both the anionic and (sodium) counterion phosphate models. However, comparison of calculated and experimental backbone conformations reveals the charge-neutralized counterion phosphate model best mimics B-DNA. Structures optimized with implicit solvent (water) are comparable to gas-phase structures, which suggests similar results should be obtained in an environment of intermediate polarity. We recommend the use of either gas-phase or water M06-2X optimizations with the counterion phosphate model to study the structure and/or reactivity of natural or modified DNA with a dinucleoside monophosphate.
Collapse
Affiliation(s)
- Cassandra D M Churchill
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, Canada T1K 3M4
| | | |
Collapse
|
28
|
Abstract
Popular explanations of substituent effects in π-stacking interactions hinge upon substituent-induced changes in the aryl π-system. This entrenched view has been used to explain substituent effects in countless stacking interactions over the past 2 decades. However, for a broad range of stacked dimers, it is shown that substituent effects are better described as arising from local, direct interactions of the substituent with the proximal vertex of the other ring. Consequently, substituent effects in stacking interactions are additive, regardless of whether the substituents are on the same or opposite rings. Substituent effects are also insensitive to the introduction of heteroatoms on distant parts of either stacked ring. This local, direct interaction viewpoint provides clear, unambiguous explanations of substituent effects for myriad stacking interactions that are in accord with robust computational data, including DFT-D and new benchmark CCSD(T) results. Many of these computational results cannot be readily explained using traditional π-polarization-based models. Analyses of stacking interactions based solely on the sign of the electrostatic potential above the face of an aromatic ring or the molecular quadrupole moment face a similar fate. The local, direct interaction model provides a simple means of analyzing substituent effects in complex aromatic systems and also offers simple explanations of the crystal packing of fluorinated benzenes and the recently published dependence of the stability of protein-RNA complexes on the regiochemistry of fluorinated base analogues [J. Am. Chem. Soc.2011, 133, 3687-3689].
Collapse
Affiliation(s)
- Steven E Wheeler
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
| |
Collapse
|
29
|
Tafipolsky M, Engels B. Accurate Intermolecular Potentials with Physically Grounded Electrostatics. J Chem Theory Comput 2011; 7:1791-803. [DOI: 10.1021/ct200185h] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Maxim Tafipolsky
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Bernd Engels
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| |
Collapse
|
30
|
Biancardi A, Biver T, Marini A, Mennucci B, Secco F. Thiazole orange (TO) as a light-switch probe: a combined quantum-mechanical and spectroscopic study. Phys Chem Chem Phys 2011; 13:12595-602. [DOI: 10.1039/c1cp20812h] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
31
|
|
32
|
North MA, Bhattacharyya S, Truhlar DG. Improved Density Functional Description of the Electrochemistry and Structure−Property Descriptors of Substituted Flavins. J Phys Chem B 2010; 114:14907-15. [DOI: 10.1021/jp108024b] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Michael A. North
- Department of Chemistry, University of Wisconsin—Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin 54702, United States, and Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Sudeep Bhattacharyya
- Department of Chemistry, University of Wisconsin—Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin 54702, United States, and Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Donald G. Truhlar
- Department of Chemistry, University of Wisconsin—Eau Claire, 105 Garfield Avenue, Eau Claire, Wisconsin 54702, United States, and Department of Chemistry and Supercomputing Institute, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|