1
|
Sun G, Kaw HY, Zhou M, Guo P, Zhu L, Wang W. Chlorinated nucleotides and analogs as potential disinfection byproducts in drinking water. JOURNAL OF HAZARDOUS MATERIALS 2023; 452:131242. [PMID: 36963195 DOI: 10.1016/j.jhazmat.2023.131242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/09/2023] [Accepted: 03/17/2023] [Indexed: 05/03/2023]
Abstract
Identification of emerging disinfection byproducts (DBPs) of health relevance is important to uncover the health risk of drinking water observed in epidemiology studies. In this study, mutagenic chlorinated nucleotides were proposed as potential DBPs in drinking water, and the formation and transformation pathways of these DBPs in chlorination of nucleotides were carefully investigated. A total of eleven chlorinated nucleotides and analogs were provisionally identified as potential DBPs, such as monochloro uridine/cytidine/adenosine acid and dichloro cytidine acid, and the formation mechanisms involved chlorination, decarbonization, hydrolysis, oxidation and decarboxylation. The active sites of nucleotides that reacted with chlorine were on the aromatic heterocyclic rings of nucleobases, and the carbon among the two nitrogen atoms in the nucleobases tended to be transformed into carboxyl group or be eliminated, further forming ring-opening or reorganization products. Approximately 0.2-4.0 % (mol/mol) of these chlorinated nucleotides and analogs finally decomposed to small-molecule aliphatic DBPs, primarily including haloacetic acids, trichloromethane, and trichloroacetaldehyde. Eight intermediates, particularly chlorinated imino-D-ribose and imino-D-ribose, were tentatively identified in chlorination of uridine. This study provides the first set of preliminary evidence for indicating the promising occurrence of chlorinated nucleotides and analogs as potential toxicological-relevant DBPs after disinfection of drinking water.
Collapse
Affiliation(s)
- Guangrong Sun
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Han Yeong Kaw
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Meijiao Zhou
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Pei Guo
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Lizhong Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China
| | - Wei Wang
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China.
| |
Collapse
|
2
|
Zhang J, Fakharzadeh A, Pan F, Roland C, Sagui C. Atypical structures of GAA/TTC trinucleotide repeats underlying Friedreich's ataxia: DNA triplexes and RNA/DNA hybrids. Nucleic Acids Res 2020; 48:9899-9917. [PMID: 32821947 PMCID: PMC7515735 DOI: 10.1093/nar/gkaa665] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/27/2020] [Accepted: 08/04/2020] [Indexed: 11/13/2022] Open
Abstract
Expansion of the GAA/TTC repeats in the first intron of the FXN gene causes Friedreich's ataxia. Non-canonical structures are linked to this expansion. DNA triplexes and R-loops are believed to arrest transcription, which results in frataxin deficiency and eventual neurodegeneration. We present a systematic in silico characterization of the possible DNA triplexes that could be assembled with GAA and TTC strands; the two hybrid duplexes [r(GAA):d(TTC) and d(GAA):r(UUC)] in an R-loop; and three hybrid triplexes that could form during bidirectional transcription when the non-template DNA strand bonds with the hybrid duplex (collapsed R-loops, where the two DNA strands remain antiparallel). For both Y·R:Y and R·R:Y DNA triplexes, the parallel third strand orientation is more stable; both parallel and antiparallel protonated d(GA+A)·d(GAA):d(TTC) triplexes are stable. Apparent contradictions in the literature about the R·R:Y triplex stability is probably due to lack of molecular resolution, since shifting the third strand by a single nucleotide alters the stability ranking. In the collapsed R-loops, antiparallel d(TTC+)·d(GAA):r(UUC) is unstable, while parallel d(GAA)·r(GAA):d(TTC) and d(GA+A)·r(GAA):d(TTC) are stable. In addition to providing new structural perspectives for specific therapeutic aims, our results contribute to a systematic structural basis for the emerging field of quantitative R-loop biology.
Collapse
Affiliation(s)
- Jiahui Zhang
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Ashkan Fakharzadeh
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Feng Pan
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA.,Department of Statistics, Florida State University, Tallahassee, FL 32306, USA
| | - Christopher Roland
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| | - Celeste Sagui
- Department of Physics, North Carolina State University, Raleigh, NC 27695-8202, USA
| |
Collapse
|
3
|
Todorova T, Miteva D, Chankova S. DNA susceptibility of Saccharomyces cerevisiae to Zeocin depends on the growth phase. Int Microbiol 2019; 22:419-428. [PMID: 30875034 DOI: 10.1007/s10123-019-00065-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 01/03/2019] [Accepted: 02/13/2019] [Indexed: 11/26/2022]
Abstract
The aim of this study was to evaluate the level of Zeocin-induced double-strand breaks (DSBs) in Saccharomyces cerevisiae cells in a different growth phase, using constant-field gel electrophoresis (CFGE). Saccharomyces cerevisiae diploid strain D7ts1 with enhanced cellular permeability was used. The effects of growth phase and treatment time were evaluated based on Zeocin-induced DSBs, measured by CFGE. Survival assay was also applied. No protoplast isolation was necessary for the detection of DSBs in strain D7ts1. Differences in the response of cells depending on the growth phase were obtained. Cells in exponential growth phase had increased DSB levels only after Zeocin treatment with concentrations equal or higher than 200 μgml-1. Increasing treatment time did not result in higher DSB levels. Oppositely, treatment of cells at the beginning of stationary phase with Zeocin concentrations resulted in more than 1.5-fold increase in DSB levels in comparison with those in untreated cells. Increased DSB levels were measured for all the treatment times. A dose-dependent decrease in cell survival was observed after Zeocin treatment with concentrations in the range of lethality LD20-LD50. A strong negative correlation was calculated between the levels of DSBs and cell survival. New information is provided concerning DNA susceptibility depending on the growth phase. DNA susceptibility is higher in cells at the beginning of stationary phase than those in exponential phase. Data presented here illustrate that the optimized by us CFGE protocol is sensitive and could be used successfully for DSB measurement in Saccharomyces cerevisiae strains with enhanced cellular permeability.
Collapse
Affiliation(s)
- Teodora Todorova
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin str., 1113, Sofia, Bulgaria
| | - Daniela Miteva
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin str., 1113, Sofia, Bulgaria
| | - Stephka Chankova
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin str., 1113, Sofia, Bulgaria.
| |
Collapse
|
4
|
Patil KM, Toh DFK, Yuan Z, Meng Z, Shu Z, Zhang H, Ong A, Krishna MS, Lu L, Lu Y, Chen G. Incorporating uracil and 5-halouracils into short peptide nucleic acids for enhanced recognition of A-U pairs in dsRNAs. Nucleic Acids Res 2018; 46:7506-7521. [PMID: 30011039 PMCID: PMC6125629 DOI: 10.1093/nar/gky631] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 06/09/2018] [Accepted: 07/03/2018] [Indexed: 01/16/2023] Open
Abstract
Double-stranded RNA (dsRNA) structures form triplexes and RNA-protein complexes through binding to single-stranded RNA (ssRNA) regions and proteins, respectively, for diverse biological functions. Hence, targeting dsRNAs through major-groove triplex formation is a promising strategy for the development of chemical probes and potential therapeutics. Short (e.g., 6-10 mer) chemically-modified Peptide Nucleic Acids (PNAs) have been developed that bind to dsRNAs sequence specifically at physiological conditions. For example, a PNA incorporating a modified base thio-pseudoisocytosine (L) has an enhanced recognition of a G-C pair in an RNA duplex through major-groove L·G-C base triple formation at physiological pH, with reduced pH dependence as observed for C+·G-C base triple formation. Currently, an unmodified T base is often incorporated into PNAs to recognize a Watson-Crick A-U pair through major-groove T·A-U base triple formation. A substitution of the 5-methyl group in T by hydrogen and halogen atoms (F, Cl, Br, and I) causes a decrease of the pKa of N3 nitrogen atom, which may result in improved hydrogen bonding in addition to enhanced base stacking interactions. Here, we synthesized a series of PNAs incorporating uracil and halouracils, followed by binding studies by non-denaturing polyacrylamide gel electrophoresis, circular dichroism, and thermal melting. Our results suggest that replacing T with uracil and halouracils may enhance the recognition of an A-U pair by PNA·RNA2 triplex formation in a sequence-dependent manner, underscoring the importance of local stacking interactions. Incorporating bromouracils and chlorouracils into a PNA results in a significantly reduced pH dependence of triplex formation even for PNAs containing C bases, likely due to an upshift of the apparent pKa of N3 atoms of C bases. Thus, halogenation and other chemical modifications may be utilized to enhance hydrogen bonding of the adjacent base triples and thus triplex formation. Furthermore, our experimental and computational modelling data suggest that PNA·RNA2 triplexes may be stabilized by incorporating a BrUL step but not an LBrU step, in dsRNA-binding PNAs.
Collapse
Affiliation(s)
- Kiran M Patil
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Desiree-Faye Kaixin Toh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Zhen Yuan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Zhenyu Meng
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Zhiyu Shu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Haiping Zhang
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Alan Ann Lerk Ong
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Manchugondanahalli S Krishna
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Lanyuan Lu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Yunpeng Lu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Gang Chen
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| |
Collapse
|
5
|
Amini SK. Relative Populations of Some Tautomeric Forms of 2'-Deoxyguanosine-5-Fluorouridine Mismatch. J Phys Chem B 2018; 122:4433-4444. [PMID: 29608855 DOI: 10.1021/acs.jpcb.8b00818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The importance of the 2'-deoxyguanosine-uridine mispair as the most occurring mismatch in transcriptional studies of RNAs from DNAs is multiplied when 5-halo-substituted uridine species cause a serious increase in the probability of its occurrence. Many studies relate this higher probability to the existence of possible tautomeric and ionic forms of its constituent bases. According to these statements, relative populations of mismatches between 5-fluorouridine and both keto and enol forms of 2'-deoxyguanosine are computed by using a conformational search. In order to have a complete scan of all of the highly probable conformers in a moderate computational time, an extensive conformational search methodology is employed here, which benefits from the advantages of both the molecular dynamics simulations and quantum mechanics calculations. The population of an enolic tautomer of normal wobble orientation is about 0.057% of that of its keto tautomer, whereas the population of an enolic tautomer of reverse wobble orientation is about 0.0054% of that of its keto tautomer. Totally, the reverse wobble orientation is about six times more populated than the normal wobble orientation. Calculated populations are in good agreement with experimental populations of closely related compounds. The reliability of the applied methodology is certified, in part, by a good agreement obtained between some experimental data and corresponding Boltzmann-weighted average data of most probable conformers such as NMR parameters. The validation of this methodology is certified with high accuracy by applying it on the substituted diuridine pairs, where experimental populations are available. Not only are the calculated populations and NMR parameters of this test in very good agreement with the experimental data, but also they are free of the ambiguities mentioned by experimentalists.
Collapse
Affiliation(s)
- Saeed K Amini
- Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
| |
Collapse
|
6
|
Structural, electronic, and reactivity parameters of some triorganotin(IV) carboxylates: a DFT analysis. Struct Chem 2017. [DOI: 10.1007/s11224-017-1068-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
7
|
Pysanenko A, Kočišek J, Nachtigallová D, Poterya V, Fárník M. Clustering of Uracil Molecules on Ice Nanoparticles. J Phys Chem A 2017; 121:1069-1077. [PMID: 28098464 DOI: 10.1021/acs.jpca.6b12594] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We generate a molecular beam of ice nanoparticles (H2O)N, N̅ ≈ 130-220, which picks up several individual gas phase uracil (U) or 5-bromouracil (BrU) molecules. The mass spectra of the doped nanoparticles prove that the uracil and bromouracil molecules coagulate to clusters on the ice nanoparticles. Calculations of U and BrU monomers and dimers on the ice nanoparticles provide theoretical support for the cluster formation. The (U)mH+ and (BrU)mH+ intensity dependencies on m extracted from the mass spectra suggest a smaller tendency of BrU to coagulate compared to U, which is substantiated by a lower mobility of bromouracil on the ice surface. The hydrated Um·(H2O)nH+ series are also reported and discussed. On the basis of comparison with the previous experiments, we suggest that the observed propensity for aggregation on ice nanoparticles is a more general trend for biomolecules forming strong hydrogen bonds. This, together with their mobility, leads to their coagulation on ice nanoparticles which is an important aspect for astrochemistry.
Collapse
Affiliation(s)
- Andriy Pysanenko
- J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences , Dolejškova 3, 182 23 Prague, Czech Republic
| | - Jaroslav Kočišek
- J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences , Dolejškova 3, 182 23 Prague, Czech Republic
| | - Dana Nachtigallová
- Institute of Organic Chemistry and Biochemistry v.v.i., The Czech Academy of Sciences , Flemingovo nám. 2, 160610 Prague 6, Czech Republic
| | - Viktoriya Poterya
- J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences , Dolejškova 3, 182 23 Prague, Czech Republic
| | - Michal Fárník
- J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences , Dolejškova 3, 182 23 Prague, Czech Republic
| |
Collapse
|