51
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Mautner FA, Taylor ER, Rozas DM, Massoud SS. Synthesis and structural characterization of dicopper(II) and dipalladium(II) complexes of 1,1,2,2-tetrakis(carboxamido-2-methylpyridyl)ethane. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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52
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Mohamed MF, Neverov AA, Brown RS. Investigation of the Effect of Oxy Bridging Groups in Dinuclear Zn(II) Complexes that Catalyze the Cleavage of a Simple Phosphate Diester RNA Analogue. Inorg Chem 2009; 48:11425-33. [DOI: 10.1021/ic9015965] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mark F. Mohamed
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - Alexei A. Neverov
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - R. Stan Brown
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
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53
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Edwards DR, Liu CT, Garrett GE, Neverov AA, Brown RS. Leaving Group Assistance in the La3+-Catalyzed Cleavage of Dimethyl (o-Methoxycarbonyl)aryl Phosphate Triesters in Methanol. J Am Chem Soc 2009; 131:13738-48. [DOI: 10.1021/ja904659e] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- David R. Edwards
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - C. Tony Liu
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - Graham E. Garrett
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - Alexei A. Neverov
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
| | - R. Stan Brown
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6
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54
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Mautner FA, Grebowicz J, Deifik PJ, Perkins RS, Massoud SS. Structural characterization of copper(II) complexes based on a new 10-membered binucleating 1,6-diazecine ligand. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.05.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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55
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Dinuclear Zn(II) catalysts as biomimics of RNA and DNA phosphoryl transfer enzymes: changing the medium from water to alcohol provides enzyme-like rate enhancements. J PHYS ORG CHEM 2009. [DOI: 10.1002/poc.1584] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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56
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Laine M, Ketomäki K, Poijärvi-Virta P, Lönnberg H. Base moiety selectivity in cleavage of short oligoribonucleotides by di- and tri-nuclear Zn(II) complexes of azacrown-derived ligands. Org Biomol Chem 2009; 7:2780-7. [PMID: 19532995 DOI: 10.1039/b904828f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cleavage of 6-mer oligoribonucleotides by the dinuclear Zn2+ complex of 1,3-bis[(1,5,9-triazacyclododecan-3-yl)oxymethyl]benzene (L1) and the trinuclear Zn2+ complex of 1,3,5-tris[(1,5,9-triazacyclododecan-3-yl)oxymethyl]benzene (L3) has been studied. The dinuclear complex cleaves at sufficiently low concentrations ([(Zn2+)2L1] < or = 0.1 mmol L(-1)) the 5'NpU3' and 5'UpN3' bonds (N = G, C, A) much more readily than the other phosphodiester bonds, but leaves the 5'UpU3' site intact. The trinuclear (Zn2+)3L3 complex, in turn, cleaves the 5'UpU3' bond more readily than any other linkages, even faster than the 5'NpU3' and 5'UpN3' sites. Somewhat unexpectedly, the 5'UpNpU3' site is cleaved only slowly by both the di- and tri-nuclear complex. The base-moiety selectivity remains qualitatively similar, though slightly less pronounced, when the hexanucleotides are closed to hairpin loops by three additional CG-pairs of 2'-O-methylribonucleotides. Phosphodiester bonds within a double helical stem are not cleaved, not even the 5'UpU3' sites. Guanine base also becomes recognized by (Zn2+)2L1 and (Zn2+)3L3, but the affinity to G is clearly lower than to U. The trinuclear cleaving agent, however, cleaves the 5'GpG3' bond only 35% less readily than the 5'UpU3' bond.
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Affiliation(s)
- Maarit Laine
- Department of Chemistry, University of Turku, FIN-20014, Turku, Finland
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57
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Liu CT, Melnychuk SA, Liu C, Neverov AA, Brown RS. Cleavage of models for RNA mediated by a diZn(II) complex of bis[1,4- N1, N1′(1,5,9-triazacyclododecanyl)]butane in methanol and ethanol. CAN J CHEM 2009. [DOI: 10.1139/v09-026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The cleavage of seven RNA model 2-hydroxypropyl aryl phosphates (1) catalyzed by a dinuclear Zn(II) complex of bis[1,4-N1,N1′(1,5,9-triazacyclododecanyl)]butane (4) was studied in methanol and ethanol at 25 °C under pH controlled conditions. The results are compared with what was reported earlier for the dinuclear Zn(II) complex of the lower homologue bis[1,3-N1,N1′(1,5,9-triazacyclododecanyl)]propane (3). In methanol, the higher homologue exhibits saturation binding with substrates having poor aryloxy leaving groups. With good leaving groups there is an observed linear dependence of kobs versus complex concentration without saturation binding over the catalyst concentration range investigated. In ethanol, strong saturation binding between the active form of the catalyst ((RO–):Zn(II)2:4) and all substrates is observed, the results observed in both solvents being similar to what was reported for the lower (RO–):Zn(II)2:3 homologue. Energetics calculations are presented for the (RO–):Zn(II)2:4-catalyzed cleavage of each substrate in both solvents to assess the catalytic efficiency via the ΔΔG‡ for catalyst binding a transition state comprising [RO–:1]‡ or its kinetic equivalent.
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Affiliation(s)
- C. Tony Liu
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, ON K7L 3N6, Canada
| | - Stephanie A. Melnychuk
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, ON K7L 3N6, Canada
| | - Chaomin Liu
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, ON K7L 3N6, Canada
| | - Alexei A. Neverov
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, ON K7L 3N6, Canada
| | - R. Stan Brown
- Department of Chemistry, Queen’s University, 90 Bader Lane, Kingston, ON K7L 3N6, Canada
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58
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Tsang WY, Edwards DR, Melnychuk SA, Liu CT, Liu C, Neverov AA, Williams NH, Brown RS. Dinuclear Zn(II) Complex Promotes Cleavage and Isomerization of 2-Hydroxypropyl Alkyl Phosphates by a Common Cyclic Phosphate Intermediate. J Am Chem Soc 2009; 131:4159-66. [DOI: 10.1021/ja900525t] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Wing Yin Tsang
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - David R. Edwards
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Stephanie A. Melnychuk
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - C. Tony Liu
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Chaomin Liu
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Alexei A. Neverov
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Nicholas H. Williams
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - R. Stan Brown
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada K7L 3N6, and Centre for Chemical Biology, Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
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59
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Humphry T, Iyer S, Iranzo O, Morrow JR, Richard JP, Paneth P, Hengge AC. Altered transition state for the reaction of an RNA model catalyzed by a dinuclear zinc(II) catalyst. J Am Chem Soc 2009; 130:17858-66. [PMID: 19053445 DOI: 10.1021/ja8059864] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cyclization of 2-(hydroxypropyl)-4-nitrophenyl phosphate (HpPNP) catalyzed by the dinuclear zinc complex of 1,3-bis(1,4,7-triazacyclonon-1-yl)-2-hydroxypropane (1) proceeds by a transition state that is different from that of the uncatalyzed reaction. Kinetic isotope effects (KIEs) measured in the nucleophilic atom and in the leaving group show that the uncatalyzed cyclization has a transition state (TS) with little phosphorus-oxygen bond fission to the leaving group ((18)k(lg) = 1.0064 +/- 0.0009 and (15)k = 1.0002 +/- 0.0002) and that nucleophilic bond formation occurs in the rate-determining step ((18)k(nuc) = 1.0326 +/- 0.0008). In the catalyzed reaction, larger leaving group isotope effects ((18)k(lg) = 1.0113 +/- 0.0005 and (15)k = 1.0015 +/- 0.0005) and a smaller nucleophile isotope effect ((18)k(nuc) = 1.0116 +/- 0.0010) indicate a later TS with greater leaving group bond fission and greater nucleophilic bond formation. These observed nucleophile KIEs are the combined effect of the equilibrium effect on deprotonation of the 2'-hydroxyl nucleophile and the KIE on the nucleophilic step. An EIE of 1.0245 for deprotonation of the hydroxyl group of HPpNP was obtained computationally. The different KIEs for the two reactions indicate that the effective catalysis by 1 is accompanied by selection for an altered transition state, presumably arising from the preferential stabilization by the catalyst of charge away from the nucleophile and toward the leaving group. These results demonstrate the potential for a catalyst using biologically relevant metal ions to select for an altered transition state for phosphoryl transfer.
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Affiliation(s)
- Tim Humphry
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322-0300, USA
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60
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61
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Liu CT, Neverov AA, Brown RS. Enzyme-like Acceleration for the Hydrolysis of a DNA Model Promoted by a Dinuclear Zn(II) Catalyst in Dilute Aqueous Ethanol. J Am Chem Soc 2008; 130:13870-2. [DOI: 10.1021/ja805801j] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- C. Tony Liu
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
| | - Alexei A. Neverov
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
| | - R. Stan Brown
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
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62
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Um IH, Han JY, Hwang SJ. Analysis of Linear Free-Energy Relationships Combined with Activation Parameters Assigns a Concerted Mechanism to Alkaline Hydrolysis of X-Substituted Phenyl Diphenylphosphinates. Chemistry 2008; 14:7324-30. [DOI: 10.1002/chem.200800553] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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63
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Neverov AA, Liu CT, Bunn SE, Edwards D, White CJ, Melnychuk SA, Brown RS. A Simple DNase Model System Comprising a Dinuclear Zn(II) Complex in Methanol Accelerates the Cleavage of a Series of Methyl Aryl Phosphate Diesters by 1011−1013. J Am Chem Soc 2008; 130:6639-49. [DOI: 10.1021/ja8006963] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexei A. Neverov
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
| | - C. Tony Liu
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
| | - Shannon E. Bunn
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
| | - David Edwards
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
| | | | | | - R. Stan Brown
- Department of Chemistry, Queen’s University, Kingston, Ontario, Canada, K7L 3N6
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64
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65
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Taran O, Medrano F, Yatsimirsky AK. Rapid hydrolysis of model phosphate diesters by alkaline-earth cations in aqueous DMSO: speciation and kinetics. Dalton Trans 2008:6609-18. [DOI: 10.1039/b807030j] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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66
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