1
|
Kimoto M, Tan HP, Matsunaga KI, Binte Mohd Mislan NA, Kawai G, Hirao I. Strict Interactions of Fifth Letters, Hydrophobic Unnatural Bases, in XenoAptamers with Target Proteins. J Am Chem Soc 2023; 145:20432-20441. [PMID: 37677157 PMCID: PMC10515488 DOI: 10.1021/jacs.3c06122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Indexed: 09/09/2023]
Abstract
XenoAptamers are DNA fragments containing additional letters (unnatural bases, UBs) that bind specifically to their target proteins with high affinities (sub-nanomolar KD values). One of the UBs is the highly hydrophobic 7-(2-thienyl)imidazo[4,5-b]pyridine (Ds), which significantly increases XenoAptamers' affinities to targets. Originally, Ds was developed as a third base pair with a complementary UB, 2-nitro-4-propynylpyrrole (Px), for replication, and thus it can be used for aptamer generation by an evolutional engineering method involving PCR amplification. However, it is unclear whether the Ds base is the best component as the hydrophobic fifth-letter ligand for interactions with target proteins. To optimize the ligand structure of the fifth letter, we prepared 13 Ds variants and examined the affinities of XenoAptamers containing these variants to target proteins. The results obtained using four XenoAptamers prepared by the replacement of Ds bases with variants indicated that subtle changes in the chemical structure of Ds significantly affect the XenoAptamer affinities. Among the variants, placing either 4-(2-thienyl)pyrrolo[2,3-b]pyridine (Ys) or 4-(2-thienyl)benzimidazole (Bs) at specific Ds positions in each original XenoAptamer greatly improved their affinities to targets. The Ys and Bs bases are variants derived by replacing only one nitrogen with a carbon in the Ds base. These results demonstrate the strict intramolecular interactions, which are not simple hydrophobic contacts between UBs and targets, thus providing a method to mature XenoAptamers' affinities to targets.
Collapse
Affiliation(s)
- Michiko Kimoto
- Xenolis
Pte. Ltd., 85 Science
Park Drive, #02-05B, The Cavendish, Singapore 118259, Singapore
| | - Hui Pen Tan
- Xenolis
Pte. Ltd., 85 Science
Park Drive, #02-05B, The Cavendish, Singapore 118259, Singapore
| | - Ken-ichiro Matsunaga
- Xenolis
Pte. Ltd., 85 Science
Park Drive, #02-05B, The Cavendish, Singapore 118259, Singapore
| | | | - Gota Kawai
- Chiba
Institute of Technology (CIT), Tsudanuma 2-17-1, Narashino, Chiba 275-0016, Japan
| | - Ichiro Hirao
- Xenolis
Pte. Ltd., 85 Science
Park Drive, #02-05B, The Cavendish, Singapore 118259, Singapore
| |
Collapse
|
2
|
Liang F, Liu YZ, Zhang P. Universal base analogues and their applications in DNA sequencing technology. RSC Adv 2013. [DOI: 10.1039/c3ra41492b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
3
|
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
|
4
|
Svozil D, Hobza P, Sponer J. Comparison of intrinsic stacking energies of ten unique dinucleotide steps in A-RNA and B-DNA duplexes. Can we determine correct order of stability by quantum-chemical calculations? J Phys Chem B 2010; 114:1191-203. [PMID: 20000584 DOI: 10.1021/jp910788e] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
High level ab initio methods have been used to study stacking interactions in ten unique base pair steps both in A-RNA and in B-DNA duplexes. The protocol for selection of geometries based on molecular dynamics (MD) simulations is proposed, and its suitability is demonstrated by comparison with stacking in steps at fiber diffraction geometries. It is shown that fiber diffraction geometries are not sufficiently accurate for interaction energy calculations. In addition, the protocol for selection of geometries based on MD simulations allows for the evaluation of the variability of the intrinsic stacking energies along the MD trajectories. The uncertainty in stacking energies (difference between the most and least stable geometry) due to the dynamical nature of systems can be, in some cases, as large as 3.0 kcal x mol(-1), which is almost 50% of the actual sequence dependence of base stacking energies (the energy difference between the most and least stable sequences). Thus, assessing the relative magnitude of the gas phase stacking energy using a single geometry for each sequence is insufficient to obtain an unambiguous order of gas phase stacking energies in canonical double helices. Though the ordering of ten unique dinucleotide steps cannot be definitive, some general conclusions were drawn. The stacking energies of base pair steps in A-RNA are more evenly separated compared to B-DNA, and their ordering is less sensitive to the dynamics of the system compared to be B-DNA. The most stable step both in B-DNA and A-RNA is the GC/GC [corrected] step that is well separated from the second most stable step CG/CG. [corrected] Also the least stable step (the CC/GG step) is well separated from the rest of the structures. The calculations further show that B-DNA stacking is favorable only marginally (on average by 1.14 kcal x mol(-1) per base pair step) over A-RNA stacking, and this difference vanishes after subtracting the stabilizing van der Waals effect of the thymine 5-methyl group that is absent in RNA. Basically, no correlation between the sequence dependence of gas phase stacking energies and the sequence dependence of DeltaG degrees(37) free energies used in nearest-neighbor models was found either for B-DNA or for A-RNA. This reflects the complexity of the balance of forces that are responsible for the sequence dependence of thermodynamics stability of nucleic acids, which masks the effect of the intrinsic interactions between the stacked base pairs.
Collapse
Affiliation(s)
- Daniel Svozil
- Faculty of Chemical Technology, Laboratory of Informatics and Chemistry, Institute of Chemical Technology, Technická 3, 166 28, Prague 6, Czech Republic.
| | | | | |
Collapse
|
5
|
Computational evaluation of the stability of 2′-O-methyl-RNA/RNA duplexes incorporating 3-deazaguanine derivatives by ab initio calculations and a molecular dynamics simulation. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2008.12.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
6
|
Lait LA, Rutledge LR, Millen AL, Wetmore SD. yDNA versus xDNA Pyrimidine Nucleobases: Computational Evidence for Dependence of Duplex Stability on Spacer Location. J Phys Chem B 2008; 112:12526-36. [DOI: 10.1021/jp805547p] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Linda A. Lait
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
| | - Lesley R. Rutledge
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
| | - Andrea L. Millen
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
| | - Stacey D. Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, Alberta, T1K 3M4, Canada
| |
Collapse
|
7
|
Sponer J, Riley KE, Hobza P. Nature and magnitude of aromatic stacking of nucleic acid bases. Phys Chem Chem Phys 2008; 10:2595-610. [PMID: 18464974 DOI: 10.1039/b719370j] [Citation(s) in RCA: 270] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This review summarises recent advances in quantum chemical calculations of base-stacking forces in nucleic acids. We explain in detail the very complex relationship between the gas-phase base-stacking energies, as revealed by quantum chemical (QM) calculations, and the highly variable roles of these interactions in nucleic acids. This issue is rarely discussed in quantum chemical and physical chemistry literature. We further extensively discuss methods that are available for base-stacking studies, complexity of comparison of stacking calculations with gas phase experiments, balance of forces in stacked complexes of nucleic acid bases, and the relation between QM and force field descriptions. We also review all recent calculations on base-stacking systems, including details analysis of the B-DNA stacking. Specific attention is paid to the highest accuracy QM calculations, to the decomposition of the interactions, and development of dispersion-balanced DFT methods. Future prospects of computational studies of base stacking are discussed.
Collapse
Affiliation(s)
- Jirí Sponer
- Institute of Organic Chemistry and Biochemistry, vvi, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Prague 6, Czech Republic
| | | | | |
Collapse
|
8
|
Langner KM, Kedzierski P, Sokalski WA, Leszczynski J. Physical nature of ethidium and proflavine interactions with nucleic acid bases in the intercalation plane. J Phys Chem B 2007; 110:9720-7. [PMID: 16686524 DOI: 10.1021/jp056836b] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
On the basis of the crystallographic structures of three nucleic acid intercalation complexes involving ethidium and proflavine, we have analyzed the interaction energies between intercalator chromophores and their four nearest bases, using a hybrid variation-perturbation method at the second-order Møller-Plesset theory level (MP2) with a 6-31G(d,p) basis set. A total MP2 interaction energy minimum precisely reproduces the crystallographic position of the ethidium chromophore in the intercalation plane between UA/AU bases. The electrostatic component constitutes the same fraction of the total energy for all three studied structures. The multipole electrostatic interaction energy, calculated from cumulative atomic multipole moments (CAMMs), was found to converge only after including components above the fifth order. CAMM interaction surfaces, calculated on grids in the intercalation planes of these structures, reasonably reproduce the alignment of intercalators in crystal structures; they exhibit additional minima in the direction of the DNA grooves, however, which also need to be examined at higher theory levels if no crystallographic data are given.
Collapse
Affiliation(s)
- Karol M Langner
- Wroclaw University of Technology, Wyb.Wyspianskiego 27, 50-370 Wroclaw, Poland
| | | | | | | |
Collapse
|
9
|
Sintim HO, Kool ET. Remarkable sensitivity to DNA base shape in the DNA polymerase active site. Angew Chem Int Ed Engl 2007; 45:1974-9. [PMID: 16506248 DOI: 10.1002/anie.200504296] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Herman O Sintim
- Department of Chemistry, Stanford University, CA 94305-5080, USA
| | | |
Collapse
|
10
|
McConnell TL, Wetmore SD. How Do Size-Expanded DNA Nucleobases Enhance Duplex Stability? Computational Analysis of the Hydrogen-Bonding and Stacking Ability of xDNA Bases. J Phys Chem B 2007; 111:2999-3009. [PMID: 17388411 DOI: 10.1021/jp0670079] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Computational chemistry (B3LYP, MP2) is used to study the properties of size-expanded DNA nucleobases generated by inserting a benzene spacer into the natural nucleobases. Although the addition of the spacer does not significantly affect the hydrogen-bonding properties of natural nucleobases, the orientation of the base about the glycosidic bond necessary for Watson-Crick binding is destabilized, which could have implications for the selectivity of expanded bases, as well as the stability of expanded duplexes. Consideration of the (stacked) binding energies in the preferred relative orientation of natural and expanded nucleobases aligned according to their centers of mass reveals that the stacking within natural dimers can be increased by up to 50% upon expansion of one nucleobase and up to 90% upon expansion of two nucleobases. The implications of these findings to the stability of expanded duplexes were revealed by considering simplified models of natural and mixed duplexes composed of four nucleobases. Although intra- and interstrand interactions within double helices are typically less than those predicted when nucleobases are stacked according to their centers of mass, some nucleobases utilize their full stacking potential within double helices, where both intra- and interstrand interactions can be significant. Most importantly, increasing the size of nucleobases within the duplex significantly increases both intra- and interstrand stacking interactions. Specifically, some interactions are double the magnitude of the corresponding intrastrand interactions in natural helices, and even greater increases in interstrand interactions are sometimes found. Thus, our work suggests that mixed duplexes composed of natural bases hydrogen bound to expanded bases may exploit the increase in the inherent stacking ability of the expanded bases in more than one way and thereby afford duplexes with greater stability than natural DNA.
Collapse
Affiliation(s)
- Tom L McConnell
- Department of Chemistry, Mount Allison University, 63C York Street, Sackville, New Brunswick, E4L 1G8, Canada
| | | |
Collapse
|
11
|
Hunter KC, Wetmore SD. Environmental Effects on the Enhancement in Natural and Damaged DNA Nucleobase Acidity Because of Discrete Hydrogen-Bonding Interactions. J Phys Chem A 2007; 111:1933-42. [PMID: 17302396 DOI: 10.1021/jp066641j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present study uses density functional theory to carefully consider the effects of the environment on the enhancement in (natural and damaged) DNA nucleobase acidities because of multiple hydrogen-bonding interactions. Although interactions with one small molecule can increase the acidity of the nucleobases by up to 60 kJ mol-1 in the gas phase, the maximum increase in enzymatic-like environments is expected to be approximately 40 kJ mol-1, which reduces to approximately 30 kJ mol-1 in water. Furthermore, the calculated (simultaneous) effects of two, three, or four molecules are increasingly less than the sum of the individual (additive) effects with an increase in the number and acidity of the small molecules bound or the dielectric constant of the solvent. Regardless of these trends, our calculations reveal that additional hydrogen-bonding interactions will have a significant effect on nucleobase acidity in a variety of environments, where the exact magnitude of the effect depends on the properties of the small molecule bound, the nucleobase binding site, and the solvent. The maximum increase in nucleobase acidity because of interactions with up to four small molecules is approximately 80 kJ mol-1 in enzymatic-like environments (or 65 kJ mol-1 in water). These results suggest that hydrogen-bonding interactions likely play an important role in many biological processes by changing the physical and chemical properties of the nucleobases.
Collapse
Affiliation(s)
- Ken C Hunter
- Department of Chemistry, Mount Allison University, 63C York Street, Sackville, New Brunswick, E4L 1G8, Canada
| | | |
Collapse
|
12
|
Hunter KC, Millen AL, Wetmore SD. Effects of Hydrogen-Bonding and Stacking Interactions with Amino Acids on the Acidity of Uracil. J Phys Chem B 2007; 111:1858-71. [PMID: 17256895 DOI: 10.1021/jp066902p] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The effects of hydrogen-bonding interactions with amino acids on the (N1) acidity of uracil are evaluated using (B3LYP) density functional theory. Many different binding arrangements of each amino acid to three uracil binding sites are considered. The effects on the uracil acidity are found to significantly depend upon the nature of the amino acid and the binding orientation, but weakly depend on the binding site. Our results reveal that in some instances small models for the amino acids can be used, while for other amino acids larger models are required to properly describe the binding to uracil. The gas-phase acidity of uracil is found to increase by up to approximately 60 kJ mol(-1) due to discrete hydrogen-bonding interactions. Although (MP2) stacking interactions with aromatic amino acids decrease the acidity of uracil, unexpected increases in the acidity are found when any of the aromatic amino acids, or the backbone, hydrogen bond to uracil. Consideration of enzymatic and aqueous environments leads to decreases in the effects of the amino acids on the acidity of uracil. However, we find that the magnitude of the decrease varies with the nature of the molecule bound, as well as the (gas-phase) binding orientations and strengths, and therefore solvation effects should be considered on a case-by-case basis in future work. Nevertheless, the effects of amino acid interactions within enzymatic environments are as much as approximately 35 kJ mol(-1). The present study has general implications for understanding the nature of active site amino acids in enzymes, such as DNA repair enzymes, that catalyze reactions involving anionic nucleobase intermediates.
Collapse
Affiliation(s)
- Ken C Hunter
- Department of Chemistry, Mount Allison University, 63C York Street, Sackville, New Brunswick E4L 1G8, Canada
| | | | | |
Collapse
|
13
|
Nitrosubstituted aromatic molecules as universal nucleobases: Computational analysis of stacking interactions. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.07.051] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
14
|
Seio K, Sasami T, Tawarada R, Sekine M. Synthesis of 2'-O-methyl-RNAs incorporating a 3-deazaguanine, and UV melting and computational studies on its hybridization properties. Nucleic Acids Res 2006; 34:4324-34. [PMID: 16936323 PMCID: PMC1636341 DOI: 10.1093/nar/gkl088] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
2′-O-Methyl-RNAs incorporating 3-deazaguanine (c3G) were synthesized by use of N,N-diphenylcarbamoyl and N,N-dimethylaminomethylene as its base protecting groups to suppress sheared-type 5′-GA-3′/5′-GA-3′ tandem mismatched base pairing which requires the N3 atom. These modified RNAs hybridized more weakly with the complementary and single mismatch-containing RNAs than the unmodified RNAs. The Tm experiments were performed to clarify the effects of replacement of the fifth G with c3G on stabilization of 2′-O-methyl-(5′-CGGCGAGGAG-3′)/5′-CUCCGAGCCG-3′ and 2′-O-methyl-(5′-CGGGGACGAG-3′)/5′-CUCGGACCCG-3′duplexes, which form sheared-type and face-to-face type 5′-GA-3′/5′-GA-3′ tandem mismatched base pairs, respectively. Consequently, this replacement led to more pronounced destabilization of the former duplex that needs the N3 atom for the sheared-type base pair than the latter that does not need it for the face-to-face type base pair. A similar tendency was observed for 2′-O-methyl-RNA/DNA duplexes. These results suggest that the N3 atom of G plays an important role in stabilization of the canonical G/C base pair as well as the base discrimination and its loss suppressed formation of the undesired sheared-type mismatched base pair. Computational studies based on ab initio calculations suggest that the weaker hydrogen bonding ability and larger dipole moment of c3G can be the origin of the lower Tm.
Collapse
Affiliation(s)
- Kohji Seio
- Frontier Collaborative Research Center, Tokyo Institute of Technology4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
- CREST, JST (Japan Science and Technology Agency)4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Takeshi Sasami
- Department of Life Science, Tokyo Institute of Technology4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
- CREST, JST (Japan Science and Technology Agency)4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Ryuya Tawarada
- Department of Life Science, Tokyo Institute of Technology4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
- CREST, JST (Japan Science and Technology Agency)4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Mitsuo Sekine
- Department of Life Science, Tokyo Institute of Technology4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
- CREST, JST (Japan Science and Technology Agency)4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan
- To whom correspondence should be addressed. Tel: +81 45 924 5706; Fax: +81 45 924 5772;
| |
Collapse
|
15
|
Sintim HO, Kool ET. Remarkable Sensitivity to DNA Base Shape in the DNA Polymerase Active Site. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200504296] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|