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Matić J, Piotrowski P, Vrban L, Kobetić R, Vianello R, Jurić I, Fabijanić I, Pernar Kovač M, Brozovic A, Piantanida I, Schmuck C, Radić Stojković M. Distinctive Nucleic Acid Recognition by Lysine-Embedded Phenanthridine Peptides. Int J Mol Sci 2024; 25:4866. [PMID: 38732083 PMCID: PMC11084427 DOI: 10.3390/ijms25094866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/25/2024] [Accepted: 04/27/2024] [Indexed: 05/13/2024] Open
Abstract
Three new phenanthridine peptide derivatives (19, 22, and 23) were synthesized to explore their potential as spectrophotometric probes for DNA and RNA. UV/Vis and circular dichroism (CD) spectra, mass spectroscopy, and computational analysis confirmed the presence of intramolecular interactions in all three compounds. Computational analysis revealed that compounds alternate between bent and open conformations, highlighting the latter's crucial influence on successful polynucleotide recognition. Substituting one glycine with lysine in two regioisomers (22, 23) resulted in stronger binding interactions with DNA and RNA than for a compound containing two glycines (19), thus emphasizing the importance of lysine. The regioisomer with lysine closer to the phenanthridine ring (23) exhibited a dual and selective fluorimetric response with non-alternating AT and ATT polynucleotides and induction of triplex formation from the AT duplex. The best binding constant (K) with a value of 2.5 × 107 M-1 was obtained for the interaction with AT and ATT polynucleotides. Furthermore, apart from distinguishing between different types of ds-DNA and ds-RNA, the same compound could recognize GC-rich DNA through distinct induced CD signals.
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Affiliation(s)
- Josipa Matić
- Laboratory for Biomolecular Interactions and Spectroscopy, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (J.M.); (R.K.); (I.J.); (I.F.); (I.P.)
| | - Patryciusz Piotrowski
- Institute for Organic Chemistry, University of Duisburg-Essen, Universitätsstrasse 7, 45141 Essen, Germany; (P.P.)
| | - Lucija Vrban
- Laboratory for the Computational Design and Synthesis of Functional Materials, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (L.V.); (R.V.)
| | - Renata Kobetić
- Laboratory for Biomolecular Interactions and Spectroscopy, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (J.M.); (R.K.); (I.J.); (I.F.); (I.P.)
| | - Robert Vianello
- Laboratory for the Computational Design and Synthesis of Functional Materials, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (L.V.); (R.V.)
| | - Ivona Jurić
- Laboratory for Biomolecular Interactions and Spectroscopy, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (J.M.); (R.K.); (I.J.); (I.F.); (I.P.)
| | - Ivana Fabijanić
- Laboratory for Biomolecular Interactions and Spectroscopy, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (J.M.); (R.K.); (I.J.); (I.F.); (I.P.)
| | - Margareta Pernar Kovač
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (M.P.K.); (A.B.)
| | - Anamaria Brozovic
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (M.P.K.); (A.B.)
| | - Ivo Piantanida
- Laboratory for Biomolecular Interactions and Spectroscopy, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (J.M.); (R.K.); (I.J.); (I.F.); (I.P.)
| | - Carsten Schmuck
- Institute for Organic Chemistry, University of Duisburg-Essen, Universitätsstrasse 7, 45141 Essen, Germany; (P.P.)
| | - Marijana Radić Stojković
- Laboratory for Biomolecular Interactions and Spectroscopy, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (J.M.); (R.K.); (I.J.); (I.F.); (I.P.)
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Yuan F, Liu X, Li J, Tan L. Interactions of arene ruthenium(II) complexes [η 6-(C 6H 6)Ru(pprip)Cl] + and [η 6-(C 6H 6)Ru(H 2iiP)Cl] + with RNA triplex poly(U)•poly(A)*poly(U). J Biol Inorg Chem 2023; 28:559-570. [PMID: 37477757 DOI: 10.1007/s00775-023-02008-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/30/2023] [Indexed: 07/22/2023]
Abstract
Two arene ruthenium(II) complexes [η6-(C6H6)Ru(pprip)Cl]PF6 (Ru1; pprip = 2-(3-phenyl-1H-pyrazol-4-yl)-imidazolo[4,5-f][1,10]phenanthroline) and [η6-(C6H6)Ru(H2iiP)Cl]PF6 (Ru2; H2iiP = 2-(indole-3-yl)-imidazolo[4,5-f][1,10]phenanthroline) have been synthesized and characterized in this work. Binding properties of Ru1 and Ru2 with the triplex RNA poly(U)•poly(A)*poly(U) were investigated by spectrophotometry and spectrofluorometry as well as viscosimetry. Analysis of spectroscopic titrations and viscosity measurements show that the two complexes bind with the triplex through intercalation, while the binding affinity for Ru2 toward the triplex is stronger than that for Ru1. Melting experiments indicate that the stabilizing effects of Ru1 and Ru2 toward the triplex differ from each other. Under the conditions used herein, Ru1 only stabilizes the Hoogsteen base-paired strand (third strand) without affecting stabilization of the Watson-Crick base-paired strand (the template duplex) of the triplex, while Ru2 stabilizes both the template duplex and the third strand. Although the two complexes prefer to stabilizing the third strand rather than the template duplex, the third-strand stabilization effect of Ru2 is stronger than that of Ru1. The obtained results of this work reveal that the planarity of the intercalative ligands plays an important role in the triplex stabilization by arene Ru(II) complexes.
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Affiliation(s)
- Feng Yuan
- College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Juan Li
- Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, People's Republic of China.
| | - Lifeng Tan
- Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, People's Republic of China.
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Wen B, Liu X, Tan L. Binding and stabilizating effect of RNA triplex poly(U)⋅poly(A)*poly(U) by enantiomers of ruthenium(II) polypyridyl complex [Ru(bpy) 2(dppx)] 2. J Biol Inorg Chem 2023:10.1007/s00775-023-02004-2. [PMID: 37452869 DOI: 10.1007/s00775-023-02004-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 05/10/2023] [Indexed: 07/18/2023]
Abstract
Two chiral ruthenium(II) polypyridyl complexes, Λ-[Ru(bpy)2(dppx)]2+ (bpy = 2,2'-bipyridine, dppx = 7,8-dimethyldipyridophenazine; Λ-1) and Δ-[Ru(bpy)2(dppx)]2+ (Δ-1) have been synthesized and characterized in this work. Interactions of Λ-1 and Δ-1 with the RNA triplex poly(U)⋅poly(A)*poly(U) have been investigated by various biophysical techniques. Spectrophotometric titrations and viscosity measurements suggested that enantiomers Λ-1 and Δ-1 bind with the triplex through intercalation, while the binding strengths of the two enantiomers toward the triplex differed only slightly from each other. Fluorescence titrations showed that although enantiomers Λ-1 and Δ-1 exhibited molecular "light switch" effects toward the triplex, the effect of Δ-1 was more marked. Furthermore, Furthermore, thermal denaturation showed that the two enantiomers have significantly different stabilizing effects on the triplex. The obtained results indicate that the racemic complex [Ru(bpy)2(dppx)]2+ is similar to a non-specific metallointercalator for the triplex investigated in this study, and chiralities of Ru(II) polypyridine complexes have an important influence on the binding and stabilizing effects of enantiomers toward the triplex. Two chiral ruthenium(II) polypyridyl complexes, Λ-[Ru(bpy)2(dppx)]2+ (bpy = 2,2'-bipyridine, dppx = 7,8-dimethyldipyridophenazine; Λ-1) and Δ-[Ru(bpy)2(dppx)]2+ (Δ-1) have been synthesized and characterized in this work. Interactions of Λ-1 and Δ-1 with the RNA triplex poly(U)⋅poly(A)*poly(U) have been investigated by various biophysical techniques. The obtained results indicate that the racemic complex [Ru(bpy)2(dppx)]2+ is similar as a non-specific metallointercalator for the triplex investigated in this study, and chiralities of Ru(II) polypyridine complexes have an important influence on the binding and stabilizing effects of enantiomers toward the triplex.
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Affiliation(s)
- Bingxin Wen
- College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, People's Republic of China.
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Wang H, Liu X, Tan L. Binding properties of a molecular "light switch" ruthenium(II) polypyridyl complex toward double- and triple-helical forms of RNA. Int J Biol Macromol 2023; 242:124710. [PMID: 37146854 DOI: 10.1016/j.ijbiomac.2023.124710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/07/2023]
Abstract
To further develop new luminescent probes for RNA, a new ruthenium(II) polypyridyl complex [Ru(dmb)2dppz-idzo]2+ (dmb = 4,4'-dimethyl-2,2'-bipyridine, dppz-idzo = dppz-imidazolone) has been synthesized and characterized in this study. Binding properties of [Ru(dmb)2dppz-idzo]2+ to RNA duplex poly(A) · poly(U) and triplex poly(U) · poly(A) ∗ poly(U) have been explored by spectroscopic techniques and viscometry experiments. The binding modes of [Ru(dmb)2dppz-idzo]2+ to RNA duplex and triplex are intercalation as revealed from spectral titrations and viscosity experiments, while the binding strength of this complex to duplex structure is significantly greater than that of triplex structure. Fluorescence titrations indicate that [Ru(dmb)2dppz-idzo]2+ can act as a molecular "light switch" for both duplex poly(A) · poly(U) and triplex poly(U) · poly(A) ∗ poly(U), while [Ru(dmb)2dppz-idzo]2+ is more sensitive to poly(A) · poly(U) compared to poly(U) · poly(A) ∗ poly(U) and poly(U). Therefore, this complex can distinguish between RNA duplex, triplex and poly(U), and can as luminescent probes for the three RNAs used in this study. In addition, thermal denaturation studies show that [Ru(dmb)2dppz-idzo]2+ is able to significantly increase the Stabilization of RNA duplex and triplex. The results obtained in this study may contribute to further understanding of the binding of Ru(II) complexes with different structural RNAs.
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Affiliation(s)
- Hui Wang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
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Peng X, Liu X, Tan L. Interaction of ruthenium(Ⅱ) polypyridyl complexes [Ru(phen)2(L)]2+ (L = PIP, p-HPIP and m-HPIP) with RNA poly(A)•poly(U): each complex unexpectedly exhibiting a destabilizing effect on RNA. Bioorg Chem 2023; 135:106523. [PMID: 37027949 DOI: 10.1016/j.bioorg.2023.106523] [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: 02/08/2023] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023]
Abstract
To further explore the binding properties of Ru(Ⅱ) polypyridine complexes with RNA, three Ru(Ⅱ) complexes [Ru(phen)2(PIP)]2+ (Ru1), [Ru(phen)2(p-HPIP)]2+ (Ru2), and [Ru(phen)2(m- HPIP)]2+ (Ru3) have been synthesized and characterized in this work. The binding properties of three Ru(Ⅱ) complexes with RNA duplex poly(A)•poly(U) have been investigated by spectral and viscosity experiments. These studies all support that these three Ru(Ⅱ) complexes bind to poly RNA duplex poly(A)•poly(U) by intercalation, and Ru1 without substituents has a stronger binding affinity for poly(A)•poly(U). Interestingly, the thermal melting experiments show that these three Ru(Ⅱ) complexes all destabilize RNA duplex poly(A)•poly(U), and the destabilizing effect can be explained by the conformational changes of duplex structure induced by intercalating agents. To the best of our knowledge, this work report for the first time a small molecule capable of destabilizing an RNA duplex, which reflects that the substitution effect of intercalated ligands has an important influence on the affinity of Ru(Ⅱ) complexes to RNA duplex, and that not all Ru(Ⅱ) complexes show thermal stability effects on an RNA duplex.
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Affiliation(s)
- Xing Peng
- College of Chemistry, Xiangtan University, Xiangtan 411105, Peoples Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, Peoples Republic of China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, XiangtanUniversity, Xiangtan 411105, Peoples Republic of China; Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan 411105, Peoples Republic of China.
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Jiao Z, Yang C, Zhou Q, Hu Z, Jie J, Zhang X, Su H. Sequence-specific binding behavior of coralyne toward triplex DNA: An ultrafast time-resolved fluorescence spectroscopy study. J Chem Phys 2023; 158:045101. [PMID: 36725513 DOI: 10.1063/5.0133913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Triplex DNA structure has potential therapeutic application in inhibiting the expression of genes involved in cancer and other diseases. As a DNA-targeting antitumor and antibiotic drug, coralyne shows a remarkable binding propensity to triplex over canonical duplex and thus can modulate the stability of triplex structure, providing a prospective gene targeting strategy. Much less is known, however, about coralyne-binding interactions with triplex. By combining multiple steady-state spectroscopy with ultrafast fluorescence spectroscopy, we have investigated the binding behaviors of coralyne with typical triplexes. Upon binding with a G-containing triplex, the fluorescence of coralyne is markedly quenched owing to the photoinduced electron transfer (PET) of coralyne with the G base. Systematic studies show that the PET rates are sensitive to the binding configuration and local microenvironment, from which the coexisting binding modes of monomeric (full and partial) intercalation and aggregate stacking along the sugar-phosphate backbone are distinguished and their respective contributions are determined. It shows that coralyne has preferences for monomeric intercalation within CGG triplex and pure TAT triplex, whereas CGC+ triplex adopts mainly backbone binding of coralyne aggregates due to charge repulsion, revealing the sequence-specific binding selectivity. The triplex-DNA-induced aggregation of coralyne could be used as a probe for recognizing the water content in local DNA structures. The strong π-π stacking of intercalated coralyne monomer with base-triplets plays an important role in stabilizing the triplex structure. These results provide mechanistic insights for understanding the remarkable propensity of coralyne in selective binding to triplex DNA and shed light on the prospective applications of coralyne-triplex targeted anti-gene therapeutics.
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Affiliation(s)
- Zeqing Jiao
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Chunfan Yang
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Qian Zhou
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Zheng Hu
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Jialong Jie
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xianwang Zhang
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Hongmei Su
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
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Peng X, Liu X, Li J, Tan L. RNA-binding of Ru(II) complexes [Ru(phen) 2(7-OCH 3-dppz)] 2+ and [Ru(phen) 2(7-NO 2-dppz)] 2+: The former serves as a molecular "light switch" for poly(A)•poly(U). J Inorg Biochem 2022; 237:111991. [PMID: 36115329 DOI: 10.1016/j.jinorgbio.2022.111991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/24/2022] [Accepted: 09/01/2022] [Indexed: 01/18/2023]
Abstract
To further determine the factors that affect the binding properties of ruthenium(II) polypyridine complexes with RNA duplex and to find excellent RNA-binding agents, the binding properties of ruthenium(II) complexes [Ru(phen)2(7-OCH3-dppz)]2+ (Ru1, phen = 1,10-phenan- throline, 7-OCH3-dppz = 7-methoxy-dipyrido-[3,2-a,2',3'-c]-phenazine) and [Ru(phen)2(7-NO2- dppz)]2+ (Ru2, 7-NO2-dppz = 7-nitro-dipyrido-[3,2-a,2',3'-c]-phenazine) with RNA poly(A)•poly(U) duplex have been investigated by spectroscopic methods and viscosity measurements in this work. The results show that complexes Ru1 and Ru2 bind to poly(A)•poly(U) through intercalation and the binding affinity between Ru2 and poly(A)•poly(U) is greater than that of Ru1. Thermal denaturation experiments suggest that both ruthenium(II) complexes exhibit a significant stabilizing effect on poly(A)•poly(U) duplex. Moreover, fluorescence emission spectra exhibit that, deviating from Ru2, Ru1 exhibits a "light switch" effect for poly(A)•poly(U). This effect can be observed by the naked eye under UV light and adjusted by pH, meaning that Ru1 may act as a reversible pH controlled molecular "light switch". The results obtained in this work will contribute to our understanding of the significant influence of the intercalative ligand substituent effect in the binding process of ruthenium(II) complexes with RNA duplex.
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Affiliation(s)
- Xing Peng
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Juan Li
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
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Fu Y, Si H, Chen J, Zhang W, Feng S, Xiao Z. A Novel “Turn‐On” Fluorescent Sensor for Screening Triplex DNA Binder Based upon Molecular Beacon. ChemistrySelect 2022. [DOI: 10.1002/slct.202203178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yuanxiang Fu
- School of Chemical Engineering Guizhou Institute of Technology 1st, Caiguan Road Guiyang 550003 P. R. China
| | - Hengdan Si
- School of Chemical Engineering Guizhou Institute of Technology 1st, Caiguan Road Guiyang 550003 P. R. China
| | - Juan Chen
- School of Chemical Engineering Guizhou Institute of Technology 1st, Caiguan Road Guiyang 550003 P. R. China
| | - Wenjuan Zhang
- School of Chemical Engineering Guizhou Institute of Technology 1st, Caiguan Road Guiyang 550003 P. R. China
| | - Shuang Feng
- School of Chemical Engineering Guizhou Institute of Technology 1st, Caiguan Road Guiyang 550003 P. R. China
| | - Zhiyou Xiao
- School of Chemical Engineering Guizhou Institute of Technology 1st, Caiguan Road Guiyang 550003 P. R. China
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Zhang J, Fakharzadeh A, Roland C, Sagui C. RNA as a Major-Groove Ligand: RNA-RNA and RNA-DNA Triplexes Formed by GAA and UUC or TTC Sequences. ACS OMEGA 2022; 7:38728-38743. [PMID: 36340174 PMCID: PMC9631886 DOI: 10.1021/acsomega.2c04358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Friedreich's ataxia is associated with noncanonical nucleic acid structures that emerge when GAA:TTC repeats in the first intron of the FXN gene expand beyond a critical number of repeats. Specifically, the noncanonical repeats are associated with both triplexes and R-loops. Here, we present an in silico investigation of all possible triplexes that form by attaching a third RNA strand to an RNA:RNA or DNA:DNA duplex, complementing previous DNA-based triplex studies. For both new triplexes results are similar. For a pyridimine UUC+ third strand, the parallel orientation is stable while its antiparallel counterpart is unstable. For a neutral GAA third strand, the parallel conformation is stable. A protonated GA+A third strand is stable in both parallel and antiparallel orientations. We have also investigated Na+ and Mg2+ ion distributions around the triplexes. The presence of Mg2+ ions helps stabilize neutral, antiparallel GAA triplexes. These results (along with previous DNA-based studies) allow for the emergence of a complete picture of the stability and structural characteristics of triplexes based on the GAA and TTC/UUC sequences, thereby contributing to the field of trinucleotide repeats and the associated unusual structures that trigger expansion.
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Yuan F, Liu X, Tan L. Binding and stabilization effect of arene ruthenium(Ⅱ) polypyridyl complexes toward the triple-helical RNA poly(U)•poly(A)⁎poly(U). Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.121140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Tan L, Wang H, Liu X. Insight into achirality and chirality effects in interactions of an racemic ruthenium(II) polypyridyl complex and its Δ- and Λ-enantiomers with an RNA triplex. Int J Biol Macromol 2022; 219:579-586. [PMID: 35952809 DOI: 10.1016/j.ijbiomac.2022.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/28/2022]
Abstract
RNA triplexes have a variety of potential applications in molecular biology, diagnostics and therapeutics, while low stabilization of the third strand hinders their practical utilities under physiological conditions. In this regard, achieving the third-strand stabilization by binding small molecules is a promising strategy. Chirality is one of the basic properties of nature. To clarify achirality and chirality effects on the binding and stabilizing effects of RNA triplexes by small molecules, we report for the first time the RNA interactions of an racemic ruthenium(II) polypyridyl complex [Ru(bpy)2(11-CN-dppz)]2+ (rac-Ru1) and its two enantiomers Δ/Λ-[Ru(bpy)2(11-CN-dppz)]2+ (Δ/Λ-Ru1) with an RNA triplex poly(U-A*U) (where "-" represents Watson-Crick base pairing, and "*" denotes Hoogsteen base pairing, respectively) in this work. Research shows that although rac-Ru1 and its two enantiomers Δ/Λ-Ru1 bind to the RNA triplex through the same mode of intercalation, the binding affinity for enantiomer Δ-Ru1 is much higher than that for rac-Ru1 and enantiomer Λ-Ru1. However, compared to enantiomer Λ-Ru1, the binding affinity for rac-Ru1 does not show much of an advantage, which is slightly greater than that for the former. Thermal denaturation measurements reveal both rac-Ru1 and Δ-Ru1 to have a preference for stabilizing the third strand rather than the template duplex of the RNA triplex, while Λ-Ru1 stabilizes the RNA triplex without significant selectivity. Besides, the third-strand stabilizing effects by rac-Ru1 and Δ-Ru1 are not markedly different from each other, but more marked than that by Λ-Ru1. This work shows that the binding properties of the racemic Ru(II) polypyridyl complex with the RNA triplex are not simply an average of its two enantiomers, indicating potentially complicated binding events.
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Affiliation(s)
- Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
| | - Hui Wang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, People's Republic of China
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Wang H, Liu X, Tan L. A naked-eye colorimetric molecular "light switch" based on ruthenium(II) polypyridyl complex [Ru(phen) 2ttbd] 2+ as binder and stabilizer for RNA duplex and triplex. Int J Biol Macromol 2022; 215:571-578. [PMID: 35752337 DOI: 10.1016/j.ijbiomac.2022.06.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 11/05/2022]
Abstract
Binding of [Ru(phen)2ttbd]2+ (phen = 1,10-phenanthroline, ttbd = 4-(6-propenylpyrido-[3,2-a]- phenzain-10-yl-benzene-1,2-diamine) to the RNA triplex poly(U-A*U) (herein "-" and "*" refer to the Watson-Crick and Hoogsteen binding, respectively) and the duplex poly(A-U) have been investigated by spectral technology and viscosity method. Analysis of spectral titrations and viscosity experiments as well as melting measurements suggest that [Ru(phen)2ttbd]2+ binds to the studied RNA triplex and duplex through intercalation, while its binding constant toward the triplex is greater than the duplex. Luminescent titrations indicate that [Ru(phen)2ttbd]2+ can act as a molecular "light switch" for the two RNAs and the switch effect can be detected by the naked-eye. Moreover, the "light switch" can be repeatedly cycled off and on by adjusting the pH of the solution, whereas color change in the case of the triplex is more significant compared with the duplex. To our knowledge, [Ru(phen)2ttbd]2+ is the first small molecule capable of serving as a pH-controlled reversible visual molecular "light switch" for both the RNA triplex poly(U-A*U) and duplex poly(A-U). Thermal denaturation experiments suggest that [Ru(phen)2ttbd]2+ can obviously increase the triplex stabilization, while it stabilizing third-strand is more marked in comparison with the template duplex of the triplex, indicating this complex preferentially binds to third-strand. The obtained results may be useful for understanding the binding of Ru(II) polypyridyl complexes to RNAs.
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Affiliation(s)
- Hui Wang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lifeng Tan
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China.
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Yuan F, Liu X, Tan L. Binding properties of ruthenium(II) complexes [Ru(phen) 2(7-R-dppz)] 2+ (R = methyl or bromine) toward poly(U)•poly(A) RNA duplex. Int J Biol Macromol 2022; 209:1648-1655. [PMID: 35489619 DOI: 10.1016/j.ijbiomac.2022.04.091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 04/12/2022] [Accepted: 04/13/2022] [Indexed: 11/18/2022]
Abstract
Two Ru(II) complexes containing different substituents, [Ru(phen)2(7-CH3-dppz)]2+ (Ru1) and [Ru(phen)2(7-Br-dppz)]2+ (Ru2), have been synthesized in this study. The binding properties of Ru1 and Ru2 with the duplex RNA poly(U)•poly(A) (where "•" denotes the Watson - Crick base pairing) have been researched by biophysical techniques and viscosity measurements. Analysis of spectral titrations and viscosity measurements indicate that Ru1 and Ru2 bind to the duplex via intercalative, and the binding affinity of Ru1 with the duplex is remarkably higher than that of Ru2. Furthermore, fluorescence emission spectra demonstrates that although complexes Ru1 and Ru2 can act as molecular "light switches" for the duplex RNA, alters in fluorescence emission of Ru1 and Ru2 are prominent differences, and the effectiveness of Ru1 is more remarkable compared with that of Ru2. The melting experiments suggest that the duplex RNA stabilizing effects of Ru1 and Ru2 differ from each other, among them, complex Ru1 can obviously enhance the stability of the duplex RNA, while Ru2 has only a slightly stabilizing effect for the duplex RNA, indicating that Ru1 preferentially binds to RNA duplex over Ru2. The obtained results indicate that subtle modifications of the intercalative ligand of Ru(II) polypyridyl complex with either methyl or bromide group have a significant effect on the duplex-binding discrimination.
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Affiliation(s)
- Feng Yuan
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
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Zhang C, Liu X, Tan L. Interaction of arene ruthenium(II) complexes [(η 6-C 6H 6)Ru(L)Cl]PF 6 (L = o-fpip and p-fpip) with the RNA triplex poly(U)*poly(A)•poly(U). J Inorg Biochem 2022; 232:111813. [PMID: 35405487 DOI: 10.1016/j.jinorgbio.2022.111813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/26/2022] [Accepted: 03/31/2022] [Indexed: 11/25/2022]
Abstract
To comprehend the binding properties of η6-arene Ru(II) complexes with poly(U)*poly(A)•poly(U) triplex, two arene Ru(II) complexes with different fluorine substituent positions, [(η6-C6H6)Ru(o-fpip)Cl]PF6 (Ru1,η6-C6H6 = benzene ring, o-fpip = 2-(2'‑fluorine) imidazo [4,5-f] Biver et al. (2008), Gupta et al. (2012) [1, 10] phenanthroline) and [(η6-C6H6)Ru(p-fpip)Cl]PF6 (Ru2,η6-C6H6 = benzene ring, o-fpip = 2-(4'‑fluorine) imidazo [4,5-f] Biver et al. (2008), Gupta et al. (2012) [1, 10] phenanthroline), have been synthesized and characterized in this study. The binding of Ru1 and Ru2 with poly(U)*poly(A)•poly(U) triplex has been investigated by viscosity measurement and spectroscopic methods. Analysis of UV-Vis absorption spectral titrations suggests that Ru1 and Ru2 bind to the triplex through an intercalative mode, but the binding affinity of Ru2 is slightly higher than that of Ru1, which is also verified by viscosity and EB (ethidium bromide) competition measurements. Furthermore, the thermal denaturation experiment shows that Ru1 and Ru2 increase the third-strand stabilization to a similar extent. Interestingly, the two complexes have essentially no effect on the stabilization of the template duplex. Considering the structure of Ru1 and Ru2, conceivably besides the intercalation of ligand, the force stabilizing the triplex should also involve covalent binding and electrostatic interaction. The obtained results will contribute to our understanding of the interaction of arene Ru(II) complexes with the poly(U)*poly(A)•poly(U) triplex.
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Affiliation(s)
- Chengqing Zhang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
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Abookleesh FL, Al-Anzi BS, Ullah A. Potential Antiviral Action of Alkaloids. Molecules 2022; 27:molecules27030903. [PMID: 35164173 PMCID: PMC8839337 DOI: 10.3390/molecules27030903] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 12/30/2022] Open
Abstract
Viral infections and outbreaks have become a major concern and are one of the main causes of morbidity and mortality worldwide. The development of successful antiviral therapeutics and vaccines remains a daunting challenge. The discovery of novel antiviral agents is a public health emergency, and extraordinary efforts are underway globally to identify safe and effective treatments for different viral diseases. Alkaloids are natural phytochemicals known for their biological activities, many of which have been intensively studied for their broad-spectrum of antiviral activities against different DNA and RNA viruses. The purpose of this review was to summarize the evidence supporting the efficacy of the antiviral activity of plant alkaloids at half-maximum effective concentration (EC50) or half-maximum inhibitory concentration (IC50) below 10 μM and describe the molecular sites most often targeted by natural alkaloids acting against different virus families. This review highlights that considering the devastating effects of virus pandemics on humans, plants, and animals, the development of high efficiency and low-toxicity antiviral drugs targeting these viruses need to be developed. Furthermore, it summarizes the current research status of alkaloids as the source of antiviral drug development, their structural characteristics, and antiviral targets. Overall, the influence of alkaloids at the molecular level suggests a high degree of specificity which means they could serve as potent and safe antiviral agents waiting for evaluation and exploitation.
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Affiliation(s)
- Frage L. Abookleesh
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Bader S. Al-Anzi
- Department of Environment Technologies and Management, Kuwait University, P.O. Box 5969, Kuwait City 13060, Kuwait;
| | - Aman Ullah
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada;
- Correspondence: ; Tel.: +1-78-0-492-4845
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Basu A, Mahammad A, Das A. Inhibition of the formation of lysozyme fibrillar assemblies by the isoquinoline alkaloid coralyne. NEW J CHEM 2022. [DOI: 10.1039/d1nj06007d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The isoquinoline alkaloid coralyne can efficiently attenuate fibrillogenesis in lysozyme.
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Affiliation(s)
- Anirban Basu
- Department of Chemistry, Vidyasagar University, Midnapore 721 102, India
| | - Adil Mahammad
- Department of Chemistry, Vidyasagar University, Midnapore 721 102, India
| | - Arindam Das
- Department of Chemistry, Vidyasagar University, Midnapore 721 102, India
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Valipour M, Zarghi A, Ebrahimzadeh MA, Irannejad H. Therapeutic potential of chelerythrine as a multi-purpose adjuvant for the treatment of COVID-19. Cell Cycle 2021; 20:2321-2336. [PMID: 34585628 PMCID: PMC8506812 DOI: 10.1080/15384101.2021.1982509] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Multifunctional nature of phytochemicals and their chemical diversity has attracted attention to develop leads originated from nature to fight COVID-19. Pharmacological activities of chelerythrine and its congeners have been studied and reported in the literature. This compound simultaneously has two key therapeutic effects for the treatment of COVID-19, antiviral and anti-inflammatory activities. Chelerythrine can prevent hyper-inflammatory immune response through regulating critical signaling pathways involved in SARS-CoV-2 infection, such as alteration in Nrf2, NF-κB, and p38 MAPK activities. In addition, chelerythrine has a strong protein kinase C-α/-β inhibitory activity suitable for cerebral vasospasm prevention and eryptosis reduction, as well as beneficial effects in suppressing pulmonary inflammation and fibrosis. In terms of antiviral activity, chelerythrine can fight with SARS-CoV-2 through various mechanisms, such as direct-acting mechanism, viral RNA-intercalation, and regulation of host-based antiviral targets. Although chelerythrine is toxic in vitro, the in vivo toxicity is significantly reduced due to its structural conversion to alkanolamine. Its multifunctional action makes chelerythrine a prominent compound for the treatment of COVID-19. Considering precautions related to the toxicity at higher doses, it is expected that this compound is useful in combination with proper antivirals to reduce the severity of COVID-19 symptoms.
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Affiliation(s)
- Mehdi Valipour
- Department of Medicinal Chemistry, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Afshin Zarghi
- Department of Pharmaceutical Chemistry, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Ali Ebrahimzadeh
- Department of Medicinal Chemistry, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Hamid Irannejad
- Department of Medicinal Chemistry, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
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Substituent effects on the interactions of ruthenium(II) polypyridyl complexes [Ru(bpy)2(6-R-dppz)]2+ (R = hydroxy and fluorine) with the RNA triplex poly(rU)·poly(rA) × poly(rU). Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115196] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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19
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Comparative studies on the binding interaction of two chiral Ru(II) polypyridyl complexes with triple- and double-helical forms of RNA. J Inorg Biochem 2020; 214:111301. [PMID: 33166867 DOI: 10.1016/j.jinorgbio.2020.111301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/12/2020] [Accepted: 10/25/2020] [Indexed: 12/27/2022]
Abstract
Two chiral Ru(II) polypyridyl complexes, Δ-[Ru(bpy)2(6-F-dppz)]2+ (Δ-1; bpy = 2,2'-bipyridine, 6-F-dppz = 6-fluorodipyrido[3,2-a:2',3'-c]phenazine) and Λ-[Ru(bpy)2(6-F-dppz)]2+ (Λ-1), have been synthesized and characterized as binders for the RNA poly(U)•poly(A)*poly(U) triplex and poly(A)•poly(U) duplex in this work. Analysis of the UV-Vis absorption spectra and fluorescence emission spectra indicates that the binding of intercalating Δ-1 with the triplex and duplex RNA is greater than that of Λ-1, while the binding affinities of the two enantiomers to triplex structure is stronger than that of duplex structure. Fluorescence titrations show that the two enantiomers can act as molecular "light switches" for triple- and double-helical RNA. Thermal denaturation studies revealed that that the two enantiomers are more stable to Watson-Crick base-paired double strand of the triplex than the Hoogsteen base-paired third strand, but their stability and selectivity are different. For Δ-enantiomer, the increase of the thermal stability of the Watson-Crick base-paired duplex (13 °C) is slightly stronger than of the Hoogsteen base-paired strand (10 °C), displaying no obvious selectivity. However, compared to the Hoogsteen base-paired strand (5 °C), the stability of the Λ-enantiomer to the Watson-Crick base-paired duplex (13 °C) is more significant, which has obvious selectivity. The overall increase in viscosity of the RNA-(Λ-1) system and its curve shape are similar to that of the RNA-(Δ-1) system, suggesting that the binding modes of two enantiomers with RNA are intercalation. The obtained results in this work may be useful for understanding the binding differences in chiral Ru(II) polypyridyl complexes toward RNA triplex and duplex.
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Malina J, Farrell NP, Brabec V. Substitution-Inert Polynuclear Platinum Complexes Inhibit Reverse Transcription Preferentially in RNA Triplex-Forming Templates. Inorg Chem 2020; 59:15135-15143. [PMID: 32988198 DOI: 10.1021/acs.inorgchem.0c02070] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
RNA triplexes are significant tertiary structure motifs that are found in many functional RNAs. Hence, small molecules capable of recognition, binding, and stabilization of the triple-helical RNA structures are emerging as attractive potential molecular biology tools and therapeutic agents. Here, we utilize methods of molecular biology and biophysics to study the interactions of a series of antitumor substitution-inert polynuclear platinum complexes (SI-PPCs) with triple-helical RNA structures. We show that SI-PPCs recognize and stabilize RNA triplexes and inhibit reverse transcription preferentially in the RNA template prone to the triplex formation. These so far unexplored properties of SI-PPCs suggest that the targeting of triple-stranded regions in RNA might contribute to the biological effects of SI-PPCs.
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Affiliation(s)
- Jaroslav Malina
- Czech Academy of Sciences, Institute of Biophysics, Kralovopolska 135, Brno CZ-61265, Czech Republic
| | - Nicholas P Farrell
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Viktor Brabec
- Czech Academy of Sciences, Institute of Biophysics, Kralovopolska 135, Brno CZ-61265, Czech Republic
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21
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Dong Z, Liu X, Tan L. Biophysical insights into the interaction of two enantiomers of Ru(II) complex [Ru(bpy) 2(7-CH 3-dppz)] 2+ with the RNA poly(U-A⁎U) triplex. J Biol Inorg Chem 2020; 25:1085-1095. [PMID: 33040210 DOI: 10.1007/s00775-020-01825-9] [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: 08/22/2020] [Accepted: 09/28/2020] [Indexed: 01/14/2023]
Abstract
To determine the factors affecting the stabilization of RNA triple-stranded structure by chiral Ru(II) polypyridyl complexes, a new pair of enantiomers, ∆-[Ru(bpy)2(7-CH3-dppz)]2+ (∆-1; bpy = 2,2'-bipyridine, 7-CH3-dppz = 7-methyl-dipyrido[3,2-a,2',3'-c]phenazine) and Λ-[Ru(bpy)2(7-CH3-dppz)]2+ (Λ-1), have been synthesized and characterized in this work. Binding properties of the two enantiomers with the RNA poly(U-A⁎U) triplex (where "-" denotes the Watson - Crick base pairing and "⁎" denotes the Hoogsteen base pairing) have been studied by spectroscopy and hydrodynamics methods. Under the conditions used in this study, changes in absorption spectra of the two enantiomers are not very different from each other when bound to the triplex, although the binding affinity of ∆-1 is higher than that of Λ-1. Fluorescence titrations and viscosity experiments give convincing evidence for a true intercalative binding of enantiomers with the triplex. However, melting experiments indicated that the two enantiomers selectively stabilized the triplex. The enantiomer ∆-1 stabilize the template duplex and third-strand of the triplex, while it's more effective for stabilization of the template duplex. In stark contrast to ∆-1, Λ-1 stabilizes the triplex without any effect on the third-strand stabilization, suggesting this one extremely prefers to stabilize the template duplex rather than third-strand. Besides, the triplex stabilization effect of ∆-1 is more marked in comparison with that of Λ-1. The obtained results suggest that substituent effects and chiralities of Ru(II) polypyridyl complexes play important roles in the triplex stabilization. Complexes Λ/Δ-[Ru(bpy)2(7-CH3-dppz)]2+ (Λ/Δ-1; bpy = 2,2'-bipyridine, 7-CH3-dppz = 7-methyl-dipyrido[3,2-a,2',3'-c]phenazine) were prepared as stabilizers for poly(U-A ∗ U) triplex. Results suggest the triplex stabilization depends the chiral structures of Λ/Δ-1, indicating that [Ru(bpy)2(7-CH3-dppz)]2+ is a non-specific intercalator for poly(U-A ∗ U) investigated in this work.
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Affiliation(s)
- Zhan Dong
- College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, People's Republic of China. .,Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan, 411105, People's Republic of China.
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22
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Tan L, Zhang J. A phenolic hydroxyl in the ortho- and meta-positions on the main ligands effect on the interactions of [Ru(phen) 2(o-HPIP)] 2+ and [Ru(phen) 2(m-HPIP)] 2+ with the poly(U)·poly(A)*poly(U) triplex. J Inorg Biochem 2020; 213:111268. [PMID: 33065523 DOI: 10.1016/j.jinorgbio.2020.111268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/23/2020] [Accepted: 09/27/2020] [Indexed: 01/14/2023]
Abstract
The association of two ruthenium(II) complexes [Ru(phen)2(o-HPIP)]2+ (Ru1; phen = 1,10-phenanthroline, o-HPIP = 2-(2-hydroxyphenyl)-imidazo[4,5-f][1,10] phenanthroline) and [Ru(phen)2(m-HPIP)]2+ (Ru2; m-HPIP = 2-(3-hydroxyphenyl)-imidazo[4,5-f][1,10]phenan- throline) with the RNA poly(U)·poly(A)⁎poly(U) triplex has been investigated by spectrophotometric titrations and melting experiments in this work. All experimental data reveal an intercalative triplex-binding mode of the two complexes, whereas the binding constant for Ru1 is significantly higher than that for Ru2. Circular dichroism spectroscopic investigations show that the two complexes could bind to the chiral environment of the triplex, but the triplex perturbation effects induced by Ru1 are more marked. Thermal denaturation experiments demonstrate that both Ru1 and Ru2 display a large binding preference and stabilizing effect for the third strand over the Watson-Crick base-paired duplex of the triplex. However, the third-strand stabilizing effect of Ru1 is much more effective than that of Ru2. The obtained results suggest that positions of the phenolic group on the main ligands have significant effect on the binding of the two complexes with poly(U)·poly(A)⁎poly(U) triplex.
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Affiliation(s)
- Lifeng Tan
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China; Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
| | - Jingwen Zhang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
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Jiang L, Liu X, Tan L. Synthesis and characterization of chiral Ru(II) polypyridyl complexes and their binding and stabilizing effects toward triple-helical RNA. J Inorg Biochem 2020; 213:111263. [PMID: 33011626 DOI: 10.1016/j.jinorgbio.2020.111263] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/10/2020] [Accepted: 09/21/2020] [Indexed: 01/11/2023]
Abstract
Two novel chiral Ru(II) complexes, Λ- and Δ-[Ru(bpy)2(7-CF3-dppz)]2+ (Λ-1 and Δ-1; bpy = 2,2'-bipyridine, 7-CF3-dppz = 7-trifluoromethyl-dipyrido[3,2-a:2',3'-c]phenazine), were synthesized and characterized in this work. The binding and stabilizing effects of Λ-1 and Δ-1 toward the RNA poly(U)•poly(A)*poly(U) triplex were studied by various biophysical techniques. Absorption spectra and fluorescence quenching indicates that the binding affinity of Δ-1 is slightly higher than that Λ-1. Both enantiomers induce significant positive viscosity changes that are indicative of intercalative binding, whereas changes in the relative viscosities of the triplex are found to be more pronounced with Δ-1. Melting experiments indicate that the triplex stabilization effects of both enantiomers are significantly different from each other. With Λ-1, the stabilization of the Watson-Crick base-paired duplex (the template duplex) of the triplex shows a moderate increase, whereas the stabilization of the Hoogsteen base-paired strand (third-strand) exhibits slight decrease under the same conditions, suggesting Λ-1 prefers to stabilize the template duplex rather than third-strand. In stark contrast to Λ-1, Δ-1 can not only strongly stabilize the template duplex, but also moderately increase the third-strand stabilization, even so, which imply that Δ-1 also prefer to stabilize the template duplex instead of the third-strand. These suggest that the [Ru(bpy)2(7-CF3-dppz)]2+ is similar as a non-specific metallointercalator the triplex studied in this work. Combined with our recent research, the obtained results further indicate that Δ- enantiomers rather than Λ-ones of Ru(II) polypyridyl complexes usually exhibit stronger binding and stabilizing effects toward the triplex.
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Affiliation(s)
- Lijuan Jiang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China; Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan 411105, People's Republic of China.
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Stabilization of an intermolecular RNA triplex by two novel binders Lys- and Arg-rich Ru(II) polypyridyl metallopeptides. J Inorg Biochem 2020; 210:111171. [DOI: 10.1016/j.jinorgbio.2020.111171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/25/2020] [Accepted: 06/25/2020] [Indexed: 11/23/2022]
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25
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Ray B, Mehrotra R. Nucleic acid binding mechanism of flavone derivative, riviciclib: Structural analysis to unveil anticancer potential. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2020; 211:111990. [PMID: 32858336 DOI: 10.1016/j.jphotobiol.2020.111990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/17/2020] [Accepted: 08/07/2020] [Indexed: 10/23/2022]
Abstract
Despite burgeoned knowledge about the origin, growth, tissue interactions, and spread of cancer in recent years, the functional complexity and unique survival ability of cancer cells still make it difficult to target them. Riviciclib is a semi-synthetic derivative of rohitukine and possesses anticancer potential. Inhibition of nucleic acid activity in an uncontrolled dividing cell can form the basis for the development of new-age cancer therapeutics. The present study reports the molecular interaction between riviciclib and nucleic acid (DNA/tRNA) using spectroscopic and molecular docking studies in an attempt to comprehend its cellular toxicity as well as the nature and mode of binding between them. Vibrational spectroscopic results suggest that riviciclib intercalates DNA duplex and primarily binds with guanine, adenine, and thymine nucleobases. While in the case of riviciclib-tRNA complexation, riviciclib interacts mostly with uracil residues of the tRNA molecule. Besides nucleobases, riviciclib interacts with the sugar-phosphate backbone of both biomacromolecules. Conformationally, DNA alters from B-form to C-form, whereas tRNA shows no change in its native A-form. The order (104 M-1) of binding constant for riviciclib-nucleic acid complexation infer moderate to strong affinity of riviciclib with DNA and tRNA, respectively. Molecular docking explorations are further in corroboration with our spectroscopic outcomes.
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Affiliation(s)
- Bhumika Ray
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Ranjana Mehrotra
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
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Brown JA. Unraveling the structure and biological functions of RNA triple helices. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1598. [PMID: 32441456 PMCID: PMC7583470 DOI: 10.1002/wrna.1598] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 04/06/2020] [Accepted: 04/15/2020] [Indexed: 02/06/2023]
Abstract
It has been nearly 63 years since the first characterization of an RNA triple helix in vitro by Gary Felsenfeld, David Davies, and Alexander Rich. An RNA triple helix consists of three strands: A Watson–Crick RNA double helix whose major‐groove establishes hydrogen bonds with the so‐called “third strand”. In the past 15 years, it has been recognized that these major‐groove RNA triple helices, like single‐stranded and double‐stranded RNA, also mediate prominent biological roles inside cells. Thus far, these triple helices are known to mediate catalysis during telomere synthesis and RNA splicing, bind to ligands and ions so that metabolite‐sensing riboswitches can regulate gene expression, and provide a clever strategy to protect the 3′ end of RNA from degradation. Because RNA triple helices play important roles in biology, there is a renewed interest in better understanding the fundamental properties of RNA triple helices and developing methods for their high‐throughput discovery. This review provides an overview of the fundamental biochemical and structural properties of major‐groove RNA triple helices, summarizes the structure and function of naturally occurring RNA triple helices, and describes prospective strategies to isolate RNA triple helices as a means to establish the “triplexome”. This article is categorized under:RNA Structure and Dynamics > RNA Structure and Dynamics RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems
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Affiliation(s)
- Jessica A Brown
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
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27
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Ivanov M, Sizov V, Kudrev A. Thermal unwinding of Polyadenylic·Polyuridylic acid complex with TMPyP4 porphyrin in aqueous solutions. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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28
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Padmapriya K, Barthwal R. Nuclear magnetic resonance based structure of the protoberberine alkaloid coralyne and its self-association by spectroscopy techniques. J Pharm Anal 2019; 9:437-448. [PMID: 31890344 PMCID: PMC6931075 DOI: 10.1016/j.jpha.2019.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/19/2019] [Accepted: 09/26/2019] [Indexed: 12/03/2022] Open
Abstract
Coralyne is an important alkaloid due to its anti-cancer and other medicinal properties. It targets DNA in cells and acts as human topoisomerase-I poison, telomerase inhibitor and nucleic acid intercalator. It has high tendency to undergo self-association, which is a matter of concern for therapeutic applications. The understanding of its interaction with DNA requires precise knowledge of chemical shifts in Nuclear Magnetic Resonance (NMR) spectra besides self-association. The present study is the first report of a complete assignment of all 1H/13C resonances in NMR spectra of coralyne in DMSO-d6 using one dimensional 1H/13C and two dimensional NMR experiments. The chemical shift of all proton and several 13C resonances have also been obtained in D2O and ethanol-d6. The same has been calculated using Density Functional Theory (DFT). NMR spectra of coralyne show upfield shift of 0.6–1.2 ppm in aromatic ring protons suggesting stacking interactions. Apart from 11 intra molecular NOE cross peaks in 2D 1H–1H ROESY spectra, 3 short distance NOE correlations, H6–10OCH3, H5–10OCH3 and H12–16CH3, give direct independent evidence of the formation of a stacked dimer. The absorbance, fluorescence, circular dichroism and fluorescence lifetime experiments conducted in the present investigations corroborate results obtained by NMR. First report of NMR chemical shifts of all 1H and 13C resonances in coralyne. Proton and carbon-13 chemical shifts calculated using Density Functional theory. Self associated coralyne shows upfield shifts up to ∼1.2 ppm in proton resonances. Three intermolecular NOEs in 2D ROESY spectra give direct proof of dimer formation. Absorbance, fluorescence and life time experiments give evidence of dimer formation.
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Affiliation(s)
- Kumar Padmapriya
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Ritu Barthwal
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
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Tarabasz D, Kukula-Koch W. Palmatine: A review of pharmacological properties and pharmacokinetics. Phytother Res 2019; 34:33-50. [PMID: 31496018 DOI: 10.1002/ptr.6504] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/18/2019] [Accepted: 08/19/2019] [Indexed: 12/11/2022]
Abstract
The aim of this review is to collect together the results of the numerous studies over the last two decades on the pharmacological properties of palmatine published in scientific databases like Scopus and PubMed, which are scattered across different publications. Palmatine, an isoquinoline alkaloid from the class of protoberberines, is a yellow compound present in the extracts from different representatives of Berberidaceae, Papaveraceae, Ranunculaceae, and Menispermaceae. It has been extensively used in traditional medicine of Asia in the treatment of jaundice, liver-related diseases, hypertension, inflammation, and dysentery. New findings describe its possible applications in the treatment of civilization diseases like central nervous system-related problems. This review intends to let this alkaloid come out from the shade of a more frequently described alkaloid: berberine. The toxicity, pharmacokinetics, and biological activities of this protoberberine alkaloid will be developed in this work.
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Affiliation(s)
| | - Wirginia Kukula-Koch
- Chair and Department of Pharmacognosy with Medicinal Plants Unit, Medical University of Lublin, Lublin, Poland
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30
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Del Mundo IMA, Vasquez KM, Wang G. Modulation of DNA structure formation using small molecules. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:118539. [PMID: 31491448 DOI: 10.1016/j.bbamcr.2019.118539] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/20/2019] [Accepted: 08/24/2019] [Indexed: 02/06/2023]
Abstract
Genome integrity is essential for proper cell function such that genetic instability can result in cellular dysfunction and disease. Mutations in the human genome are not random, and occur more frequently at "hotspot" regions that often co-localize with sequences that have the capacity to adopt alternative (i.e. non-B) DNA structures. Non-B DNA-forming sequences are mutagenic, can stimulate the formation of DNA double-strand breaks, and are highly enriched at mutation hotspots in human cancer genomes. Thus, small molecules that can modulate the conformations of these structure-forming sequences may prove beneficial in the prevention and/or treatment of genetic diseases. Further, the development of molecular probes to interrogate the roles of non-B DNA structures in modulating DNA function, such as genetic instability in cancer etiology are warranted. Here, we discuss reported non-B DNA stabilizers, destabilizers, and probes, recent assays to identify ligands, and the potential biological applications of these DNA structure-modulating molecules.
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Affiliation(s)
- Imee M A Del Mundo
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723, USA
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723, USA.
| | - Guliang Wang
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, 1400 Barbara Jordan Blvd., Austin, TX 78723, USA
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31
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Tan Z, Zhu J, Ni W, Liu X, Li Y, Tan L. Binding properties of two ruthenium(II) polypyridyl complexes [Ru(bpy) 2(dppz-Br)] 2+ and [Ru(dmb) 2(dppz-Br)] 2+ with the RNA poly(U)•poly(A)*poly(U) triplex. J Biol Inorg Chem 2019; 24:721-731. [PMID: 31312912 DOI: 10.1007/s00775-019-01685-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 07/08/2019] [Indexed: 01/14/2023]
Abstract
Two ruthenium(II) polypyridyl complexes containing different ancillary ligands, [Ru(bpy)2(dppz-Br)]2+ (Ru1; bpy = 2,2'-bipyridine dppz-Br = 7-Br-dipyrido[3,2-a,2',3'-c]-phenazine) and [Ru(dmb)2(dppz-Br)]2+ (Ru2; dmb = 4,4'-dimethyl-2,2'-bipyridine), have been synthesized and characterized. Binding properties of Ru1 and Ru2 with the RNA poly(U)•poly(A)*poly(U) triplex have been investigated by UV-Vis spectroscopy, fluorescence spectroscopy, viscosity measurements as well as circular dichroism and thermal denaturation. Spectrophotometric studies together with viscosity measurements suggest that both Ru1 and Ru2 bind with the triplex by intercalation mode, and the melting experiments demonstrate that the two complexes can effectively enhance the triplex stabilization. However, results indicate that Ru1 stabilizes the third-strand and Watson-Crick base-paired duplex of the triplex without obvious selectivity. In contrast, Ru2 prefers to bind with the third strand rather than the Watson-Crick base-paired duplex of the triplex to a some extent under the same conditions used in this study, thereby significantly stabilizing the third strand. The obtained results of this study suggest that slight differences in the ancillary ligands bpy and dmb should be the main factor affecting the binding interactions of the two complexes with the triplex.
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Affiliation(s)
- Zanru Tan
- College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Juan Zhu
- College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Wen Ni
- College of Chemistry, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan, 411105, People's Republic of China
| | - Yi Li
- Key Laboratory of Theoretical Organic Chemistry and Function Molecule, Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, People's Republic of China. .,Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan, 411105, People's Republic of China.
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32
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Wang F, Sun Y, Liu X, Li Y, Tan L. Third-strand stabilizing effects of the RNA poly(U)·poly(A)*poly(U) triplex by a ruthenium(II) polypyridine complex and its hexaarginine peptide conjugate. Int J Biol Macromol 2019; 135:1134-1141. [PMID: 31176864 DOI: 10.1016/j.ijbiomac.2019.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/28/2019] [Accepted: 06/04/2019] [Indexed: 01/14/2023]
Abstract
In this work, a Ru(II) complex [Ru(bpy)2(pip-CO2H)]2+ (Ru1) and its hexaarginine peptide conjugate [Ru(bpy)2(pic-Arg6)]8+ (Ru2) have been synthesized and characterized. The binding of Ru1 and Ru2 with poly(U)•poly(A)*poly(U) triplex has been studied. Results suggest that Ru1 binds in the surface of the minor groove while Ru2 binds to the minor groove of the triplex. Consequently, the triplex stabilization is barely affected by Ru1, while with Ru2 the triplex stabilizing effect is so strong that that dissociation of the triplex shows an overlapping of both melting processes with the melting temperature increased to a maximum of 56.1 °C at the CRu2/CUAU ratio of 0.05, where ΔTm1 and ΔTm2 are 19.6 and 10.1 °C, respectively. Furthermore, the effect of Ru2 stabilizing the third strand at such a low binding ratio of 0.05 is more marked than what obsereved for flavone luteolin and [Ru(bpy)2(mdpz)]2+, which are so far the strongest triplex stabilizers in the reported organic small molecules and metal complexes, respectively. Considering the structure natures of Ru2, conceivably except for electrostatic interaction, the forces stabilizing the triplex should also involve hydrophobic interaction and hydrogen bingding. To our knowledge, this work represents a first example of improving the triplex stabilization by a metallopeptide.
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Affiliation(s)
- Fangfang Wang
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Yanmei Sun
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Xiaohua Liu
- Academic Affairs Office, Xiangtan University, Xiangtan 411105, PR China
| | - Yi Li
- Key Laboratory of Theoretical Organic Chemistry and Function Molecule, Ministry of Education, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, PR China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, PR China; Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan 411105, PR China.
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Basu A, Suresh Kumar G. Interaction of proflavine with the RNA polynucleotide polyriboadenylic acid-polyribouridylic acid: photophysical and calorimetric studies. J Biomol Struct Dyn 2019; 38:1590-1597. [PMID: 31057051 DOI: 10.1080/07391102.2019.1615001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The binding of proflavine, an acriflavine derivative, with the RNA polynucletodide polyadenylic acid-polyuridylic acid is investigated here to understand the structural and thermodynamic basis of the binding process. Such binding data are crucial for designing viable theraperutic agents. Spectroscopic studies clearly suggest a strong binding interaction between proflavine and polyadenylic acid-polyuridylic acid leading to efficient energy transfer between the poly AU base pairs and proflavine. The stoichiometry of proflavine polyadenylic acid-polyuridylic acid binding was independently estimated by continuous variation analysis of Job. An intercalative binding model is envisaged for the binding from hydrodynamic studies. Circular dichroism experiments revealed that the binding induced conformational changes in the RNA, and also led to induction of optical activity in the bound dye molecules. The binding affinity of the complex was deduced to be (6.57 ± 0.75) 105 M-1 at (298.15 ± 0.10) K from isothermal titration calorimetry experiment. Positive entropy and negative enthalpy changes characterized the complexation. The binding was observed to be weaker both at higher temperatures and increased [Na+]. The affinity of binding decreased with increasing [Na+]. When the Gibbs energy was parsed between polyelectrolytic and nonpolyelectropytic components, it surprisingly revealed a higher role for the non-polyelectrolytic forces. These results present new data for developing RNA targeted ligands.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Anirban Basu
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India.,Department of Chemistry and Chemical Technology, Vidyasagar University, Midnapore, India
| | - Gopinatha Suresh Kumar
- Organic and Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
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34
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Wang F, Ma S, Feng Y, Liu X, Tan L. Binding propterties of two Ru(II) polypyridyl complexes containing dppz units and fluorine groups with poly(U)·poly(A) ∗ poly(U) triplex. J Inorg Biochem 2019; 197:110705. [PMID: 31071642 DOI: 10.1016/j.jinorgbio.2019.110705] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/26/2019] [Accepted: 05/01/2019] [Indexed: 01/14/2023]
Abstract
In this work, two Ru(II)-dppz (dppz = dipyrido[3,2-a:2',3'-c]phenazine) complexes containing fluorine substituents, [Ru(bpy)2(7-F-dppz)]2+ (Ru1, bpy = 2,2'-bipyridine, 7-F-dppz = 7-fluorodipyrido[3,2-a:2',3'-c]phenazine) and [Ru(phen)2(7-F-dppz)]2+ (Ru2, phen = 1,10-phenanthroline), have been synthesized and characterized. Binding properties of Ru1 and Ru2 with the RNA poly(U)·poly(A) ∗ poly(U) triplex have been studied by spectroscopic methods and viscosity measurements. The obtained results indicate that the binding differences of the two complexes with the triplex may be attributed to the ancillary ligand effects, implying that the better planarity and greater hydrophobicity of ancillary ligands are advantageous to the π-π stacking interaction between Ru2 and the triplex, thus Ru2 stabilizes the triplex strongly than Ru1. Denaturation of the triplex shows that both Ru1 and Ru2 can not only highly stabilize the template duplex of the triplex, but also significantly stabilize the third strand. Compared with the triplex stabilizing effects for the reported Ru(II)-dppz complexes, thermal melting experiments suggest that the fluorine substituent on the ligand dppz can probably decrease electrostatic repulsion between the three strands of the triplex, thereby Ru1 and Ru2 significantly increase the triplex stabilization. Results obtained from this work further confirm that the substituent electron effect of dppz-based ligands and the planarity and hydrophobicity of ancillary ligands play an important role in the triplex stabilizing effects by Ru(II)-dppz complexes.
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Affiliation(s)
- Fangfang Wang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Shuai Ma
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Yongdeng Feng
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- School of Chemical Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China; Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan 411105, People's Republic of China.
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35
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Feng Y, Liu X, Ma S, Wang F, Tan L. Ruthenium(II) polypyridyl complex [Ru(phen) 2dppz-idzo] 2+ as a colorimetric molecular "light switch" and powerful stabilizer for the RNA triplex poly(U)·poly(A)*poly(U). SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 212:240-245. [PMID: 30641364 DOI: 10.1016/j.saa.2018.12.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/09/2018] [Accepted: 12/27/2018] [Indexed: 06/09/2023]
Abstract
The interaction of [Ru(phen)2dppz-idzo]2+ (phen = 1,10-phenanthroline, dppz-idzo = dppz-imidazolone) with triplex RNA poly(U)·poly(A)*poly(U) was carried out by using spectroscopic and viscometric techniques in this work. Luminescent titrations suggest that [Ru(phen)2dppz-idzo]2+ shows better selectivity for poly(U)·poly(A)*poly(U) compared with poly(U)·poly(A) and poly(U), this complex exhibits a "light switch" effect with an emission enhancement factor of about 123 in the presence of poly(U)·poly(A)*poly(U). Significantly, this "light switch" behavior could even be observed by the naked eye under irradiation with UV light. To our knowledge, [Ru(bpy)2dppz-idzo]2+ is the first small molecule able to serve as a colorimetric molecular "light switch" for the triplex poly(U)·poly(A)*poly(U). Combined with the spectral and viscometric results as well as [Ru(phen)2dppz-idzo]2+ stabilizing the template duplex poly(U)·poly(A), we speculate that [Ru(phen)2dppz-idzo]2+ prefers to bind with the Hoogsteen base-paired strand (the third strand) of the triplex, thus the intercalating [Ru(phen)2dppz-idzo]2+ stabilizing the third strand is more marked in comparison with the Watson-Crick base-paired duplex of the triplex. The results obtained here may be useful for understanding the interaction of triplex RNA poly(U)·poly(A)*poly(U) with small molecule, particularly ruthenium(II) complexes.
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Affiliation(s)
- Yongdeng Feng
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiaohua Liu
- School of Chemical Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Shuai Ma
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Fangfang Wang
- College of Chemistry, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China.
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36
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Ma S, Wang F, Feng Y, Liu X, Tan L. Binding properties of ruthenium(II) complexes [Ru(phen)2(dicnq)]2+ and [Ru(bpy)2(dicnq)]2+ with the RNA triplex poly(U)·poly(A)*poly(U). Polyhedron 2019. [DOI: 10.1016/j.poly.2019.01.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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37
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Zarudnaya MI, Kolomiets IM, Potyahaylo AL, Hovorun DM. Structural transitions in poly(A), poly(C), poly(U), and poly(G) and their possible biological roles. J Biomol Struct Dyn 2018; 37:2837-2866. [PMID: 30052138 DOI: 10.1080/07391102.2018.1503972] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The homopolynucleotide (homo-oligonucleotide) tracts function as regulatory elements at various stages of mRNAs life cycle. Numerous cellular proteins specifically bind to these tracts. Among them are the different poly(A)-binding proteins, poly(C)-binding proteins, multifunctional fragile X mental retardation protein which binds specifically both to poly(G) and poly(U) and others. Molecular mechanisms of regulation of gene expression mediated by homopolynucleotide tracts in RNAs are not fully understood and the structural diversity of these tracts can contribute substantially to this regulation. This review summarizes current knowledge on different forms of homoribopolynucleotides, in particular, neutral and acidic forms of poly(A) and poly(C), and also biological relevance of homoribopolynucleotide (homoribo-oligonucleotide) tracts is discussed. Under physiological conditions, the acidic forms of poly(A) and poly(C) can be induced by proton transfer from acidic amino acids of proteins to adenine and cytosine bases. Finally, we present potential mechanisms for the regulation of some biological processes through the formation of intramolecular poly(A) duplexes.
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Affiliation(s)
- Margarita I Zarudnaya
- a Department of Molecular and Quantum Biophysics , Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine , Kyiv , Ukraine
| | - Iryna M Kolomiets
- a Department of Molecular and Quantum Biophysics , Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine , Kyiv , Ukraine
| | - Andriy L Potyahaylo
- a Department of Molecular and Quantum Biophysics , Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine , Kyiv , Ukraine
| | - Dmytro M Hovorun
- a Department of Molecular and Quantum Biophysics , Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine , Kyiv , Ukraine.,b Department of Molecular Biotechnology and Bioinformatics , Institute of High Technologies, Taras Shevchenko National University of Kyiv , Kyiv , Ukraine
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38
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Donlic A, Morgan BS, Xu JL, Liu A, Roble C, Hargrove AE. Discovery of Small Molecule Ligands for MALAT1 by Tuning an RNA-Binding Scaffold. Angew Chem Int Ed Engl 2018; 57:13242-13247. [PMID: 30134013 DOI: 10.1002/anie.201808823] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Indexed: 01/08/2023]
Abstract
Structural studies of the 3'-end of the oncogenic long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) confirmed a unique triple-helix structure. This structure enables accumulation of the transcript, and high levels of MALAT1 are found in several cancers. Here, we synthesize a small molecule library based on an RNA-binding scaffold, diphenylfuran (DPF), screen it against a variety of nucleic acid constructs, and demonstrate for the first time that the MALAT1 triple helix can be selectively targeted with small molecules. Computational analysis revealed a trend between subunit positioning and composition on DPF shape and intramolecular interactions, which in turn generally correlated with selectivity and binding strengths. This work thus provides design strategies toward chemical probe development for the MALAT1 triple helix and suggests that comprehensive analyses of RNA-focused libraries can generate insights into selective RNA recognition.
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Affiliation(s)
- Anita Donlic
- Department of Chemistry, Duke University, Durham, NC, 27708-0346, USA
| | - Brittany S Morgan
- Department of Chemistry, Duke University, Durham, NC, 27708-0346, USA
| | - Jason L Xu
- Department of Chemistry, Duke University, Durham, NC, 27708-0346, USA
| | - Anqi Liu
- Department of Chemistry, Duke University, Durham, NC, 27708-0346, USA
| | - Carlos Roble
- Department of Chemistry, Duke University, Durham, NC, 27708-0346, USA
| | - Amanda E Hargrove
- Department of Chemistry, Duke University, Durham, NC, 27708-0346, USA
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39
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Donlic A, Morgan BS, Xu JL, Liu A, Roble C, Hargrove AE. Discovery of Small Molecule Ligands for MALAT1 by Tuning an RNA‐Binding Scaffold. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808823] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Anita Donlic
- Department of ChemistryDuke University Durham NC 27708-0346 USA
| | | | - Jason L. Xu
- Department of ChemistryDuke University Durham NC 27708-0346 USA
| | - Anqi Liu
- Department of ChemistryDuke University Durham NC 27708-0346 USA
| | - Carlos Roble
- Department of ChemistryDuke University Durham NC 27708-0346 USA
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40
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Basu A, Kumar GS. Nucleic acids binding strategies of small molecules: Lessons from alkaloids. Biochim Biophys Acta Gen Subj 2018; 1862:1995-2016. [DOI: 10.1016/j.bbagen.2018.06.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/11/2018] [Accepted: 06/11/2018] [Indexed: 01/14/2023]
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41
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Carr CE, Khutsishvili I, Marky LA. Energetics, Ion, and Water Binding of the Unfolding of AA/UU Base Pair Stacks and UAU/UAU Base Triplet Stacks in RNA. J Phys Chem B 2018; 122:7057-7065. [PMID: 29932334 DOI: 10.1021/acs.jpcb.8b05575] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Triplex formation occurs via interaction of a third strand with the major groove of double-stranded nucleic acid, through Hoogsteen hydrogen bonding. In this work, we use a combination of temperature-dependent UV spectroscopy and differential scanning calorimetry to determine complete thermodynamic profiles for the unfolding of polyadenylic acid (poly(rA))·polyuridylic acid (poly(rU)) (duplex) and poly(rA)·2poly(rU) (triplex). Our thermodynamic results are in good agreement with the much earlier work of Krakauer and Sturtevant using only UV melting techniques. The folding of these two helices yielded an uptake of ions, Δ nNa+ = 0.15 mol Na+/mol base pair (duplex) and 0.30 mol Na+/mole base triplet (triplex), which are consistent with their polymer behavior and the higher charge density parameter of triple helices. The osmotic stress technique yielded a release of structural water, Δ nW = 2 mol H2O/mol base pair (duplex unfolding into single strands) and an uptake of structural water, Δ nW = 2 mol H2O/mole base pair (triplex unfolding into duplex and a single strand). However, an overall release of electrostricted waters is obtained for the unfolding of both complexes from pressure perturbation calorimetric experiments. In total, the Δ V values obtained for the unfolding of triplex into duplex and a single strand correspond to an immobilization of two structural waters and a release of three electrostricted waters. The Δ V values obtained for the unfolding of duplex into two single strands correspond to the release of two structural waters and the immobilization of four electrostricted water molecules.
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Affiliation(s)
- Carolyn E Carr
- Department of Pharmaceutical Sciences , University of Nebraska Medical Center , 986025 Nebraska Medical Center , Omaha , Nebraska 68198-6025 , United States
| | - Irine Khutsishvili
- Department of Pharmaceutical Sciences , University of Nebraska Medical Center , 986025 Nebraska Medical Center , Omaha , Nebraska 68198-6025 , United States
| | - Luis A Marky
- Department of Pharmaceutical Sciences , University of Nebraska Medical Center , 986025 Nebraska Medical Center , Omaha , Nebraska 68198-6025 , United States
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Binding properties of chiral ruthenium(II) complexes Λ- and Δ-[Ru(bpy) 2dppz-11-CO 2Me] 2+ toward the triplex RNA poly(U)•poly(A)*poly(U). J Inorg Biochem 2018; 186:51-59. [PMID: 29852349 DOI: 10.1016/j.jinorgbio.2018.05.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/20/2018] [Accepted: 05/22/2018] [Indexed: 12/29/2022]
Abstract
Two chiral ruthenium(II) complexes containing ligand dppz-CO2Me (dppz-11-CO2Me = dipyrido[3,2-a,2',3'-c]phenazine-11-carboxylic acid methyl ester), Δ-[Ru(bpy)2dppz-11-CO2Me]2+ (bpy = 2,2'-bipyridine; Δ-1) and Λ-[Ru(bpy)2dppz-11-CO2Me]2+ (Λ-1), were synthesized and characterized. The binding of the two enantiomers with the triplex RNA poly(U)•poly(A)*poly(U) was carried out by various biophysical techniques. Analysis of the absorption and fluorescence features indicates that the binding strengths of the two enantiomers toward the triplex RNA differ only slightly from each other. The total increase in viscosity and shape of the curves for the triplex RNA with Λ-1 is similar to that with Δ-1, suggesting the binding modes of two enantiomers with the triplex RNA are intercalation. Thermal melting measurements indicate that the stabilization effects clearly depended on the concentrations of Λ-1 and Δ-1. However, the third-strand stabilizing effect of Δ-1 dramatically differs from that of Λ-1 when they interact with the chiral environment of the RNA triple at pH = 7.0 and [Na+] = 35 mM. Combined with the CD (CD = circular dichroism) variations of the triplex RNA with either Λ-1 or Δ-1, the reason for their different triplex stabilization effects may originate from the two enantiomers through different orientations intercalating into nucleobases of the triplex. In addition, effects of higher ionic strengths on the triplex stabilization in the absence and presence of the two enantiomers have also been studied. The results presented here may be useful for understanding the binding properties of the triplex RNA with small molecule, particularly chiral ruthenium(II) complexes.
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Peng M, Ni W, Tan L. Effects of the fluorine substituent positions of the intercalating ligands on the binding behavior and third-strand stabilization of two Ru(II) complexes toward poly(U)•poly(A)*poly(U) triplex RNA. J Inorg Biochem 2017; 175:276-283. [PMID: 28806644 DOI: 10.1016/j.jinorgbio.2017.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 07/10/2017] [Accepted: 08/05/2017] [Indexed: 01/03/2023]
Abstract
Two new Ru(II) polypyridyl complexes containing fluorine substituents, [Ru(bpy)2(o-fpip)]2+ (Ru1, bpy=2,2'-bipyridine, o-fpip=2-(2-fluorophenyl)imidazo[4,5-f] [1,10]phenanthroline) and [Ru(bpy)2(p-fpip)]2+ (Ru2, p-fpip=2-(4-fluorophenyl)imidazo[4,5-f] [1,10]phenanthroline) have been synthesized as binders for poly(U)•poly(A)∗poly(U) triplex RNA. The binding of the two complexes with the triplex RNA has been investigated by spectroscopic methods and viscosity measurements. Analysis of the electronic absorption spectra indicates that the association of intercalating Ru2 with the triplex RNA is greater than that of Ru1, which is also supported by spectroscopic titrations and viscosity measurements. Thermal denaturation studies reflect that third-strand stabilization depend on the nature of the two complexes and Ru2 is more effective for stabilization of the triplex RNA. Circular dichroism spectra of the triplex RNA in the presence of metal complexes indicate that the binding-induced CD perturbation of the triplex structure is more obvious by Ru2. The main results obtained here suggest that the positions of fluorine substituent in the intercalating ligands have a significant effect on the two complexes stabilizing the third strand.
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Affiliation(s)
- Mengna Peng
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Wen Ni
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, PR China.
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Tang W, Zhu Z, Tan L. [Ru(bpy)2(7-CH3-dppz)](2+) and [Ru(phen)2(7-CH3-dppz)](2+) as metallointercalators that affect third-strand stabilization of the poly(U)˙poly(A)*poly(U) triplex. MOLECULAR BIOSYSTEMS 2017; 12:1478-85. [PMID: 26999574 DOI: 10.1039/c6mb00094k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Stable RNA triplexes play key roles in many biological processes. However, due to Hoogsteen base pairing, triplexes are thermodynamically less stable than the corresponding duplexes. To understand the factors effecting the stabilization of RNA triplexes by octahedral ruthenium(ii) complexes, two Ru(ii) complexes, [Ru(bpy)2(7-CH3-dppz)](2+) (Ru) and [Ru(phen)2(7-CH3-dppz)](2+) (Ru), have been synthesized and characterized in this work. The interactions of the two Ru(ii) complexes with the poly(U)˙poly(A)*poly(U) triplex are investigated by spectrophotometry, spectrofluorometry, circular dichroism as well as viscometry. The results demonstrate that the two complexes are able to enhance the stability of the RNA triplex and serve as molecular "light switches" for the triplex. However, Ru and Ru affecting the stabilization of the third strand are significantly weaker than that of the Watson-Crick base-paired duplex, suggesting that the binding of the two complexes with the triplex is favored by the Watson-Crick base-paired duplex to a large extent. In addition, considering the nature of Ru and Ru, we presume that their binding differences may be due to different ancillary ligand effects. This study further advances our knowledge on the interaction of RNA triple-stranded structures with metal complexes, particularly with Ru(ii) complexes.
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Affiliation(s)
- Wuzhi Tang
- College of Chemistry, Xiangtan University, Xiangtan 411105, P. R. China.
| | - Zhiyuan Zhu
- College of Chemistry, Xiangtan University, Xiangtan 411105, P. R. China.
| | - Lifeng Tan
- College of Chemistry, Xiangtan University, Xiangtan 411105, P. R. China. and Key Lab of Environmentally Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, P. R. China
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Peng MN, Zhu ZY, Tan LF. Binding Differences of Two Homochiral [Ru(bpy) 2dppz] 2+ Complexes with poly(U)·poly(A)*poly(U) Triplex RNA. Inorg Chem 2017. [PMID: 28636339 DOI: 10.1021/acs.inorgchem.7b00670] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The first investigation of chiral ruthenium(II) complexes Δ- and Λ-[Ru(bpy)2dppz]2+ and triplex RNA poly(U)·poly(A)*poly(U) was carried out, which showed that Δ enantiomer displayed significant ability in stabilizing model triplex RNA.
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Affiliation(s)
- Meng-Na Peng
- Key Laboratory of Environment-friendly Chemistry and Application in Ministry of Education and ‡College of Chemistry, Xiangtan University , Xiangtan 411105, China
| | - Zhi-Yuan Zhu
- Key Laboratory of Environment-friendly Chemistry and Application in Ministry of Education and ‡College of Chemistry, Xiangtan University , Xiangtan 411105, China
| | - Li-Feng Tan
- Key Laboratory of Environment-friendly Chemistry and Application in Ministry of Education and ‡College of Chemistry, Xiangtan University , Xiangtan 411105, China
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Zhu Z, Peng M, Zhang J, Tan L. Interaction of octahedral ruthenium(II) polypyridyl complex [Ru(bpy) 2(PIP)] 2+ with poly(U)·poly(A)*poly(U) triplex: Increasing third-strand stabilization of the triplex without affecting the stability of the duplex. J Inorg Biochem 2017; 169:44-49. [PMID: 28104569 DOI: 10.1016/j.jinorgbio.2017.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 01/10/2023]
Abstract
Triple-helical RNA are of interest because of possible biological roles as well as the potential therapeutic uses of these structures, while the stability of triplexes is usually weaker than that of the Watson-Crick base pairing duplex strand due to the electrostatic repulsion between three polyanionic strands. Therefore, how to increase the stability of the specific sequences of triplexes are of importance. In this paper the binding of a Ru(II) complex, [Ru(bpy)2(PIP)]2+ (bpy=2.2'-bipyridine, PIP=2-phenyl-1H-imidazo[4,5-f]- [1,10]-phenanthroline), with poly(U)·poly(A)*poly(U) triplex has been investigated by spectrophotometry, spectrofluorometry, viscosimetry and circular dichroism. The results suggest that [Ru(bpy)2(PIP)]2+ as a metallointercalator can stabilize poly(U)·poly(A)*poly(U) triplex (where · denotes the Watson-Crick base pairing and * denotes the Hoogsteen base pairing),while it stabilizes third-strand with no obvious effect on the duplex of poly(U)·poly(A), reflecting the binding of this complex with the triplex is favored by the Hoogsteen paired poly(U) third strand to a great extent.
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Affiliation(s)
- Zhiyuan Zhu
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Mengna Peng
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Jingwen Zhang
- College of Chemistry, Xiangtan University, Xiangtan 411105, PR China
| | - Lifeng Tan
- Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, PR China.
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Padmapriya K, Barthwal R. Binding of the alkaloid coralyne to parallel G-quadruplex DNA [d(TTGGGGT)]4 studied by multi-spectroscopic techniques. Biophys Chem 2016; 219:49-58. [DOI: 10.1016/j.bpc.2016.09.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 08/17/2016] [Accepted: 09/17/2016] [Indexed: 11/16/2022]
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48
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Structural and thermodynamic analysis of the binding of tRNAphe by the putative anticancer alkaloid chelerythrine: Spectroscopy, calorimetry and molecular docking studies. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2016; 161:335-44. [DOI: 10.1016/j.jphotobiol.2016.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 05/27/2016] [Indexed: 12/15/2022]
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49
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Hu Y, Lin F, Wu T, Wang Y, Zhou XS, Shao Y. Fluorescently Sensing of DNA Triplex Assembly Using an Isoquinoline Alkaloid as Selector, Stabilizer, Inducer, and Switch-On Emitter. Chem Asian J 2016; 11:2041-8. [DOI: 10.1002/asia.201600459] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Indexed: 01/07/2023]
Affiliation(s)
- Yuehua Hu
- Institute of Physical Chemistry; Zhejiang Normal University; Jinhua 321004 Zhejiang People's Republic of China
| | - Fan Lin
- Institute of Physical Chemistry; Zhejiang Normal University; Jinhua 321004 Zhejiang People's Republic of China
| | - Tao Wu
- Institute of Physical Chemistry; Zhejiang Normal University; Jinhua 321004 Zhejiang People's Republic of China
| | - Ying Wang
- Institute of Physical Chemistry; Zhejiang Normal University; Jinhua 321004 Zhejiang People's Republic of China
| | - Xiao-Shun Zhou
- Institute of Physical Chemistry; Zhejiang Normal University; Jinhua 321004 Zhejiang People's Republic of China
| | - Yong Shao
- Institute of Physical Chemistry; Zhejiang Normal University; Jinhua 321004 Zhejiang People's Republic of China
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50
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An overview on the interaction of phenazinium dye phenosafranine to RNA triple and double helices. Int J Biol Macromol 2016; 86:345-51. [DOI: 10.1016/j.ijbiomac.2016.01.078] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/15/2016] [Accepted: 01/21/2016] [Indexed: 12/22/2022]
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