1
|
Svenningsen SW, Luige O, Abdulkarim Z, Strömberg R, Williams NH. Zinc N, N-bis(2-picolyl)amine Chelates Show Substitution-Dependent Cleavage of Phosphodiesters in Models as Well as of PNAzyme-RNA Bulges. Molecules 2024; 29:2123. [PMID: 38731616 PMCID: PMC11085541 DOI: 10.3390/molecules29092123] [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: 03/01/2024] [Revised: 04/20/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
PNAzymes are a group of artificial enzymes which show promising results in selective and efficient cleavage of RNA targets. In the present study, we introduce a series of metal chelating groups based on N,N-bis(2-picolyl) groups (parent, 6-methyl and 6-amino substituted) as the active sites of novel PNAzymes. An improved synthetic route for the 6-amino analogues is described. The catalytic activity of the chelating groups for cleaving phosphodiesters were assessed with the model substrate 2-hydroxypropyl p-nitrophenyl phosphate (HPNPP), confirming that the zinc complexes have the reactivity order of parent < 2-methyl < 2-amino. The three ligands were conjugated to a PNA oligomer to form three PNAzymes which showed the same order of reactivity and some sensitivity to the size of the RNA bulge designed into the catalyst-substrate complex. This work demonstrates that the kinetic activity observed for the model substrate HPNPP could be translated onto the PNAzymes, but that more reactive Zn complexes are required for such PNAzymes to be viable therapeutic agents.
Collapse
Affiliation(s)
- Søren W. Svenningsen
- Department of Chemistry, University of Sheffield, Richard Roberts Building, Sheffield S3 7HF, UK; (S.W.S.); (Z.A.)
| | - Olivia Luige
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, Halsovagen 9, 14157 Huddinge, Sweden;
| | - Zeyed Abdulkarim
- Department of Chemistry, University of Sheffield, Richard Roberts Building, Sheffield S3 7HF, UK; (S.W.S.); (Z.A.)
| | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, Halsovagen 9, 14157 Huddinge, Sweden;
- Department of Laboratory Medicine, Karolinska Institutet, ANA Futura, Nobels alle 8 B, 14152 Huddinge, Sweden
| | - Nicholas H. Williams
- Department of Chemistry, University of Sheffield, Richard Roberts Building, Sheffield S3 7HF, UK; (S.W.S.); (Z.A.)
| |
Collapse
|
2
|
Luige O, Karalė K, Bose PP, Bollmark M, Tedebark U, Murtola M, Strömberg R. Influence of sequence variation on the RNA cleavage activity of Zn 2+-dimethyl-dppz-PNA-based artificial enzymes. RSC Adv 2022; 12:5398-5406. [PMID: 35425588 PMCID: PMC8981518 DOI: 10.1039/d1ra08319h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/30/2022] [Indexed: 11/21/2022] Open
Abstract
The development of Zn2+-dependent dimethyl-dppz-PNA conjugates (PNAzymes) as efficient site-specific artificial ribonucleases enables rapid sequence-specific degradation of clinically relevant RNA target sequences, but the significance of the RNA/PNAzyme sequence and structural demands for the identification of novel RNA targets are not fully understood. In the present study, we investigated the influence of sequence variation in the recognition arms of the RNA/PNAzyme complex on the RNA cleavage activity of the artificial enzymes. The base pairs closing the 3-nucleotide bulge region on both sides of the bulge as well as the neighbouring nucleobases were shown to significantly influence the RNA cleavage activity. Elongation of the RNA/PNAzyme complex was shown to be tolerated, although potentially prohibitive for catalytic turnover. The specificity of PNAzyme action was clearly demonstrated by the significantly reduced or absent cleavage activity in complexes containing mismatches. Further investigation into 2- and 4-nucleotide RNA bulges indicated that formation of 3-nucleotide bulges in the target RNA gives the optimal cleavage rates, while some potential off-target cleavage of formed 4-nucleotide bulges of select sequences should be considered.
Collapse
Affiliation(s)
- Olivia Luige
- Department of Biosciences and Nutrition, Karolinska Institutet Neo, 141 83 Huddinge Sweden
| | - Kristina Karalė
- Department of Biosciences and Nutrition, Karolinska Institutet Neo, 141 83 Huddinge Sweden
- RISE, Department of Chemical Process and Pharmaceutical Development Forskargatan 18 15136 Södertälje Sweden
| | - Partha Pratim Bose
- Department of Biosciences and Nutrition, Karolinska Institutet Neo, 141 83 Huddinge Sweden
| | - Martin Bollmark
- RISE, Department of Chemical Process and Pharmaceutical Development Forskargatan 18 15136 Södertälje Sweden
| | - Ulf Tedebark
- RISE, Department of Chemical Process and Pharmaceutical Development Forskargatan 18 15136 Södertälje Sweden
| | - Merita Murtola
- Department of Biosciences and Nutrition, Karolinska Institutet Neo, 141 83 Huddinge Sweden
| | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet Neo, 141 83 Huddinge Sweden
| |
Collapse
|
3
|
Amirloo B, Staroseletz Y, Yousaf S, Clarke DJ, Brown T, Aojula H, Zenkova MA, Bichenkova EV. "Bind, cleave and leave": multiple turnover catalysis of RNA cleavage by bulge-loop inducing supramolecular conjugates. Nucleic Acids Res 2021; 50:651-673. [PMID: 34967410 PMCID: PMC8789077 DOI: 10.1093/nar/gkab1273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 12/23/2022] Open
Abstract
Antisense sequence-specific knockdown of pathogenic RNA offers opportunities to find new solutions for therapeutic treatments. However, to gain a desired therapeutic effect, the multiple turnover catalysis is critical to inactivate many copies of emerging RNA sequences, which is difficult to achieve without sacrificing the sequence-specificity of cleavage. Here, engineering two or three catalytic peptides into the bulge-loop inducing molecular framework of antisense oligonucleotides achieved catalytic turnover of targeted RNA. Different supramolecular configurations revealed that cleavage of the RNA backbone upon sequence-specific hybridization with the catalyst accelerated with increase in the number of catalytic guanidinium groups, with almost complete demolition of target RNA in 24 h. Multiple sequence-specific cuts at different locations within and around the bulge-loop facilitated release of the catalyst for subsequent attacks of at least 10 further RNA substrate copies, such that delivery of only a few catalytic molecules could be sufficient to maintain knockdown of typical RNA copy numbers. We have developed fluorescent assay and kinetic simulation tools to characterise how the limited availability of different targets and catalysts had restrained catalytic reaction progress considerably, and to inform how to accelerate the catalytic destruction of shorter linear and larger RNAs even further.
Collapse
Affiliation(s)
- Bahareh Amirloo
- School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Yaroslav Staroseletz
- Institute of Chemical Biology and Fundamental Medicine SB RAS, 8 Laurentiev Avenue, 630090 Novosibirsk, Russian Federation
| | - Sameen Yousaf
- School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - David J Clarke
- School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Tom Brown
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Harmesh Aojula
- School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Marina A Zenkova
- Institute of Chemical Biology and Fundamental Medicine SB RAS, 8 Laurentiev Avenue, 630090 Novosibirsk, Russian Federation
| | - Elena V Bichenkova
- School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| |
Collapse
|
4
|
Site-Selective Artificial Ribonucleases: Renaissance of Oligonucleotide Conjugates for Irreversible Cleavage of RNA Sequences. Molecules 2021; 26:molecules26061732. [PMID: 33808835 PMCID: PMC8003597 DOI: 10.3390/molecules26061732] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 11/17/2022] Open
Abstract
RNA-targeting therapeutics require highly efficient sequence-specific devices capable of RNA irreversible degradation in vivo. The most developed methods of sequence-specific RNA cleavage, such as siRNA or antisense oligonucleotides (ASO), are currently based on recruitment of either intracellular multi-protein complexes or enzymes, leaving alternative approaches (e.g., ribozymes and DNAzymes) far behind. Recently, site-selective artificial ribonucleases combining the oligonucleotide recognition motifs (or their structural analogues) and catalytically active groups in a single molecular scaffold have been proven to be a great competitor to siRNA and ASO. Using the most efficient catalytic groups, utilising both metal ion-dependent (Cu(II)-2,9-dimethylphenanthroline) and metal ion-free (Tris(2-aminobenzimidazole)) on the one hand and PNA as an RNA recognising oligonucleotide on the other, allowed site-selective artificial RNases to be created with half-lives of 0.5-1 h. Artificial RNases based on the catalytic peptide [(ArgLeu)2Gly]2 were able to take progress a step further by demonstrating an ability to cleave miRNA-21 in tumour cells and provide a significant reduction of tumour growth in mice.
Collapse
|
5
|
Luige O, Murtola M, Ghidini A, Strömberg R. Further Probing of Cu 2+-Dependent PNAzymes Acting as Artificial RNA Restriction Enzymes. Molecules 2019; 24:molecules24040672. [PMID: 30769777 PMCID: PMC6412939 DOI: 10.3390/molecules24040672] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/11/2019] [Accepted: 02/13/2019] [Indexed: 11/16/2022] Open
Abstract
Peptide nucleic acid (PNA)-neocuproine conjugates have been shown to efficiently catalyse the cleavage of RNA target sequences in the presence of Cu2+ ions in a site-specific manner. These artificial enzymes are designed to force the formation of a bulge in the RNA target, the sequence of which has been shown to be key to the catalytic activity. Here, we present a further investigation into the action of Cu2+-dependent PNAzymes with respect to the dependence on bulge composition in 3- and 4-nucleotide bulge systems. Cu2+-dependent PNAzymes were shown to have a clear preference for 4-nucleotide bulges, as the cleavage of 3-nucleotide bulge-forming RNA sequences was significantly slower, which is illustrated by a shift in the half-lives from approximately 30 min to 24 h. Nonetheless, the nucleotide preferences at different positions in the bulge displayed similar trends in both systems. Moreover, the cleavage site was probed by introducing critical chemical modifications to one of the cleavage site nucleotides of the fastest cleaved 4-nucleotide RNA bulge. Namely, the exclusion of the exocyclic amine of the central adenine and the replacement of the 2′-hydroxyl nucleophile with 2′-H or 2′-OMe substituents in the RNA severely diminished the rate of RNA cleavage by the Cu2+-dependent PNAzyme, giving insight into the mechanism of cleavage. Moreover, the shorter recognition arm of the RNA/PNAzyme complex was modified by extending the PNAzyme by two additional nucleobases. The new PNAzyme was able to efficiently promote the cleavage of RNA when fully hybridised to a longer RNA target and even outperform the previous fastest PNAzyme. The improvement was demonstrated in cleavage studies with stoichiometric amounts of either PNAzyme present, and the extended PNAzyme was also shown to give turnover with a 10-fold excess of the RNA target.
Collapse
Affiliation(s)
- Olivia Luige
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, 141 83 Huddinge, Stockholm, Sweden.
| | - Merita Murtola
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, 141 83 Huddinge, Stockholm, Sweden.
- Department of Chemistry, University of Turku, FI-20014 Turku, Finland.
| | - Alice Ghidini
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, 141 83 Huddinge, Stockholm, Sweden.
- Institut für Pharmazeutische Wissenschaften (IPW), Eidgenössische Technische Hochschule Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland.
| | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet, Neo, 141 83 Huddinge, Stockholm, Sweden.
| |
Collapse
|
6
|
Gahtory D, Murtola M, Smulders MMJ, Wennekes T, Zuilhof H, Strömberg R, Albada B. Facile functionalization of peptide nucleic acids (PNAs) for antisense and single nucleotide polymorphism detection. Org Biomol Chem 2018; 15:6710-6714. [PMID: 28766647 DOI: 10.1039/c7ob01592e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this report, we show how a convenient on-resin copper-click functionalization of azido-functionalized peptide nucleic acids (PNAs) allows various PNA-based detection strategies. Firstly, a thiazole orange (TO) clicked PNA probe facilitates a binary readout when combined with F/Q labeled DNA, giving increased sensitivity for antisense detection. Secondly, our TO-PNA conjugate also allows single nucleotide polymorphism detection. Since antisense detection is also possible in the absence of the TO label, our sensing platform based on azido-d-ornithine containing PNA even allows for additional and more advanced functionalization and sensing strategies.
Collapse
Affiliation(s)
- Digvijay Gahtory
- Laboratory of Organic Chemistry, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
7
|
Murtola M, Ghidini A, Virta P, Strömberg R. Zinc Ion-Dependent Peptide Nucleic Acid-Based Artificial Enzyme that Cleaves RNA-Bulge Size and Sequence Dependence. Molecules 2017; 22:molecules22111856. [PMID: 29109368 PMCID: PMC6150328 DOI: 10.3390/molecules22111856] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 11/17/2022] Open
Abstract
In this report, we investigate the efficiency and selectivity of a Zn2+-dependent peptide nucleic acid-based artificial ribonuclease (PNAzyme) that cleaves RNA target sequences. The target RNAs are varied to form different sizes (3 and 4 nucleotides, nt) and sequences in the bulge formed upon binding to the PNAzyme. PNAzyme-promoted cleavage of the target RNAs was observed and variation of the substrate showed a clear dependence on the sequence and size of the bulge. For targets that form 4-nt bulges, we identified systems with an improved efficacy (an estimated half-life of ca 7–8 h as compared to 11–12 h for sequences studied earlier) as well as systems with an improved site selectivity (up to over 70% cleavage at a single site as compared to 50–60% with previous targets sequences). For targets forming 3-nt bulges, the enhancement compared to previous systems was even more pronounced. Compared to a starting point of targets forming 3-nt AAA bulges (half-lives of ca 21–24 h), we could identify target sequences that were cleaved with half-lives three times lower (ca 7–8 h), i.e., at rates similar to those found for the fastest 4-nt bulge system. In addition, with the 3-nt bulge RNA target site selectivity was improved even further to reach well over 80% cleavage at a specific site.
Collapse
Affiliation(s)
- Merita Murtola
- Department of Chemistry, University of Turku, 20014 Turku, Finland.
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 83 Huddinge, Stockholm, Sweden.
| | - Alice Ghidini
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 83 Huddinge, Stockholm, Sweden.
| | - Pasi Virta
- Department of Chemistry, University of Turku, 20014 Turku, Finland.
| | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 83 Huddinge, Stockholm, Sweden.
| |
Collapse
|
8
|
Ghidini A, Murtola M, Strömberg R. Influence of conjugation and other structural changes on the activity of Cu²⁺ based PNAzymes. Org Biomol Chem 2016; 14:2768-73. [PMID: 26856621 DOI: 10.1039/c5ob02394g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have previously shown that PNA-neocuproine conjugates can act as artificial RNA restriction enzymes. In the present study we have additionally conjugated the PNA with different entities, such as oligoethers, peptides etc. and also constructed systems where the PNA is designed to clamp the target RNA forming a triplex. Some conjugations are detrimental for the activity while most are silent which means that conjugation can be done to alter physical properties without losing activity. Conjugation with a single oligoether close to the neocuproine does enhance the rate almost twofold compared to the system without the oligoether. The systems designed to clamp the RNA target by forming a triplex retain the activity if the added oligoT sequence is 5 PNA units or shorter and extends the arsenal of artificial RNA restriction enzymes. Changing the direction of a closing base pair, where the target RNA forms a bulge, from a GC to a CG pair enhances the rate of cleavage somewhat without compromising the selectivity, leading to the so far most efficient artificial nuclease reported.
Collapse
Affiliation(s)
- A Ghidini
- Karolinska Institutet, Department of Biosciences and Nutrition, Novum, Hälsovägen 7, S-14183 Huddinge, Sweden.
| | - M Murtola
- Karolinska Institutet, Department of Biosciences and Nutrition, Novum, Hälsovägen 7, S-14183 Huddinge, Sweden. and Turku University, Department of Chemistry, Turku 20014, Finland
| | - R Strömberg
- Karolinska Institutet, Department of Biosciences and Nutrition, Novum, Hälsovägen 7, S-14183 Huddinge, Sweden.
| |
Collapse
|
9
|
Ghidini A, Bergquist H, Murtola M, Punga T, Zain R, Strömberg R. Clamping of RNA with PNA enables targeting of microRNA. Org Biomol Chem 2016; 14:5210-3. [PMID: 27203783 DOI: 10.1039/c6ob00516k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
To be able to target microRNAs also at stages where these are in a double stranded or hairpin form we have studied BisPNA designed to clamp the target and give sufficient affinity to allow for strand invasion. We show that BisPNA complexes are more stable with RNA than with DNA. In addition, 24-mer BisPNA (AntimiR) constructs form complexes with a hairpin RNA that is a model of the microRNA miR-376b, suggesting that PNA-clamping may be an effective way of targeting microRNAs.
Collapse
Affiliation(s)
- Alice Ghidini
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 83 Huddinge, Stockholm, Sweden.
| | | | | | | | | | | |
Collapse
|
10
|
Dogandzhiyski P, Ghidini A, Danneberg F, Strömberg R, Göbel MW. Studies on Tris(2-aminobenzimidazole)-PNA Based Artificial Nucleases: A Comparison of Two Analytical Techniques. Bioconjug Chem 2015; 26:2514-9. [PMID: 26544527 DOI: 10.1021/acs.bioconjchem.5b00534] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A new peptide nucleic acid (PNA) construct carrying a tris(2-aminobenzimidazole) phosphodiester cleaver is presented. This non-metal-based artificial nuclease hydrolyzes RNA substrates that form a bulge upon binding to the PNA. Reaction rates depend on the bulge sequence. For conjugates of tris(2-aminobenzimidazole), substrate turnover is shown for the first time. Two methods of analysis for the kinetics are compared: IE-HPLC separation of oligonucleotide fragments and analysis of Cy5-labeled oligonucleotide fragments by denaturating PAGE on a DNA sequencer, respectively. The different methods give rates that are in the same range where, in general, the substrates for the sequencer method give slightly lower rates.
Collapse
Affiliation(s)
- Plamena Dogandzhiyski
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt , Max-von-Laue-Str. 7, D-60439 Frankfurt am Main, Germany
| | - Alice Ghidini
- Department of Biosciences and Nutrition, Karolinska Institutet , Novum, S-14157, Huddinge, Sweden
| | - Friederike Danneberg
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt , Max-von-Laue-Str. 7, D-60439 Frankfurt am Main, Germany
| | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet , Novum, S-14157, Huddinge, Sweden
| | - Michael W Göbel
- Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt , Max-von-Laue-Str. 7, D-60439 Frankfurt am Main, Germany
| |
Collapse
|
11
|
Milton S, Honcharenko D, Rocha CSJ, Moreno PMD, Smith CIE, Strömberg R. Nuclease resistant oligonucleotides with cell penetrating properties. Chem Commun (Camb) 2015; 51:4044-7. [PMID: 25664358 DOI: 10.1039/c4cc08837a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
2'-O-AECM modified oligonucleotides provide an unusual combination of remarkable properties. This includes the combination of high resistance towards enzymatic degradation and the spontaneous cellular uptake of AECM oligonucleotides.
Collapse
Affiliation(s)
- Stefan Milton
- Karolinska Institutet, Department of Biosciences and Nutrition, Novum, Hälsovägen 7, SE-14183, Huddinge, Sweden.
| | | | | | | | | | | |
Collapse
|
12
|
Danneberg F, Ghidini A, Dogandzhiyski P, Kalden E, Strömberg R, Göbel MW. Sequence-specific RNA cleavage by PNA conjugates of the metal-free artificial ribonuclease tris(2-aminobenzimidazole). Beilstein J Org Chem 2015; 11:493-8. [PMID: 25977723 PMCID: PMC4419560 DOI: 10.3762/bjoc.11.55] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/02/2015] [Indexed: 12/19/2022] Open
Abstract
Tris(2-aminobenzimidazole) conjugates with antisense oligonucleotides are effective site-specific RNA cleavers. Their mechanism of action is independent of metal ions. Here we investigate conjugates with peptide nucleic acids (PNA). RNA degradation occurs with similar rates and substrate specificities as in experiments with DNA conjugates we performed earlier. Although aggregation phenomena are observed in some cases, proper substrate recognition is not compromised. While our previous synthesis of 2-aminobenzimidazoles required an HgO induced cyclization step, a mercury free variant is described herein.
Collapse
Affiliation(s)
- Friederike Danneberg
- Institute for Organic Chemistry and Chemical Biology, Goethe Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt am Main, Germany
| | - Alice Ghidini
- Karolinska Institutet, Department of Biosciences and Nutrition, Novum, SE-141 83 Huddinge, Sweden
| | - Plamena Dogandzhiyski
- Institute for Organic Chemistry and Chemical Biology, Goethe Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt am Main, Germany
| | - Elisabeth Kalden
- Institute for Organic Chemistry and Chemical Biology, Goethe Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt am Main, Germany
| | - Roger Strömberg
- Karolinska Institutet, Department of Biosciences and Nutrition, Novum, SE-141 83 Huddinge, Sweden
| | - Michael W Göbel
- Institute for Organic Chemistry and Chemical Biology, Goethe Universität Frankfurt, Max-von-Laue-Straße 7, D-60438 Frankfurt am Main, Germany
| |
Collapse
|
13
|
Stephan H, Foerster C, Gasser G. Synthesis, characterization, and evaluation of radiometal-containing peptide nucleic acids. Methods Mol Biol 2014; 1050:37-54. [PMID: 24297349 DOI: 10.1007/978-1-62703-553-8_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Peptide nucleic acids (PNAs) have very attractive properties for applications in nuclear medicine. Because PNAs have high selectivity for DNA/RNA recognition, resistance to nuclease/protease degradation, and high thermal and radiolytic stabilities, PNA bioconjugates could transform the areas of diagnostic and therapeutic nuclear medicine. In this book chapter, we report on the current developments towards the preparation of radiometal-containing PNA constructs and summarize the protocols for labeling these probes with (99m)Tc, (111)In, (64)Cu, (90)Y, and (177)Lu.
Collapse
Affiliation(s)
- Holger Stephan
- Institute of Radiopharmaceutical Cancer Research, Helmholtz- Zentrum Dresden-Rossendorf, Dresden, Germany
| | | | | |
Collapse
|
14
|
Ghidini A, Ander C, Winqvist A, Strömberg R. An RNA modification with remarkable resistance to RNase A. Chem Commun (Camb) 2014; 49:9036-8. [PMID: 23982594 DOI: 10.1039/c3cc44621b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A 3'-deoxy-3'-C-methylenephosphonate modified diribonucleotide is highly resistant to degradation by spleen phosphodiesterase and not cleaved at all by snake venom phosphodiesterase. The most remarkable finding is that, despite the fact that both the vicinal 2-hydroxy nucleophile and the 5'-oxyanion leaving group are intact, the 3'-methylenephosponate RNA modification is also highly resistant towards the action of RNase A.
Collapse
Affiliation(s)
- Alice Ghidini
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Hälsovägen 7, 14183, Huddinge, Sweden.
| | | | | | | |
Collapse
|
15
|
Ghidini A, Steunenberg P, Murtola M, Strömberg R. Synthesis of PNA oligoether conjugates. Molecules 2014; 19:3135-48. [PMID: 24633349 PMCID: PMC6270860 DOI: 10.3390/molecules19033135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/01/2014] [Accepted: 03/04/2014] [Indexed: 11/16/2022] Open
Abstract
Several different approaches have been explored for conjugation of oligoethers to PNA with internally or N-terminal placed diaminopropionic acid residues. Single and double conjugation of 2-(2-(2-aminoethoxy)ethoxy)ethanol was obtained using carbonyldimidazole. Using a post PNA-assembly coupling procedure the building block 2-(2-(2-(benzoyloxy)ethoxy)ethoxy)acetic acid multiple attachment of 2-(2-(2-hydroxyethoxy)ethoxy)acetyl groups to both N-terminal and β-amino groups of inserted diaminopropionic acids residues was achieved. Use of a new oligoether functionalized amino acid allows inclusion of oligoether conjugates during on-line machine assisted synthesis which also allowed combination of methods for attachment of different oligoethers and co-conjugation of neocuproine as well as conjugation of an aminosugar.
Collapse
Affiliation(s)
- Alice Ghidini
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Hälsovägen Huddinge 7, 14183, Sweden.
| | - Peter Steunenberg
- ICL-IP Terneuzen, Frankrijkweg BJ, Terneuzen 6 4538, The Netherlands.
| | - Merita Murtola
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Hälsovägen Huddinge 7, 14183, Sweden.
| | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Hälsovägen Huddinge 7, 14183, Sweden.
| |
Collapse
|
16
|
Ruiz-Mirazo K, Briones C, de la Escosura A. Prebiotic Systems Chemistry: New Perspectives for the Origins of Life. Chem Rev 2013; 114:285-366. [DOI: 10.1021/cr2004844] [Citation(s) in RCA: 563] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kepa Ruiz-Mirazo
- Biophysics
Unit (CSIC-UPV/EHU), Leioa, and Department of Logic and Philosophy
of Science, University of the Basque Country, Avenida de Tolosa 70, 20080 Donostia−San Sebastián, Spain
| | - Carlos Briones
- Department
of Molecular Evolution, Centro de Astrobiología (CSIC−INTA, associated to the NASA Astrobiology Institute), Carretera de Ajalvir, Km 4, 28850 Torrejón de Ardoz, Madrid, Spain
| | - Andrés de la Escosura
- Organic
Chemistry Department, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| |
Collapse
|
17
|
Milton S, Ander C, Honcharenko D, Honcharenko M, Yeheskiely E, Strömberg R. Synthesis and Stability of a 2′-O-[N-(Aminoethyl)carbamoyl]methyladenosine-Containing Dinucleotide. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300699] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
18
|
Niittymäki T, Burakova E, Laitinen E, Leisvuori A, Virta P, Lönnberg H. Zn2+Complexes of 3,5-Bis[(1,5,9-triazacyclododecan-3-yloxy)methyl]phenyl Conjugates of Oligonucleotides as Artificial RNases: The Effect of Oligonucleotide Conjugation on Uridine Selectivity of the Cleaving Agent. Helv Chim Acta 2013. [DOI: 10.1002/hlca.201200153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
19
|
Desbouis D, Troitsky IP, Belousoff MJ, Spiccia L, Graham B. Copper(II), zinc(II) and nickel(II) complexes as nuclease mimetics. Coord Chem Rev 2012. [DOI: 10.1016/j.ccr.2011.12.005] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
20
|
Dong Z, Luo Q, Liu J. Artificial enzymes based on supramolecular scaffolds. Chem Soc Rev 2012; 41:7890-908. [DOI: 10.1039/c2cs35207a] [Citation(s) in RCA: 297] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
21
|
Dong Z, Yongguo Wang, Yin Y, Liu J. Supramolecular enzyme mimics by self-assembly. Curr Opin Colloid Interface Sci 2011. [DOI: 10.1016/j.cocis.2011.08.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
22
|
Gasser G, Neumann S, Ott I, Seitz M, Heumann R, Metzler-Nolte N. Preparation and Biological Evaluation of Di-Hetero-Organometallic-Containing PNA Bioconjugates. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100734] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
23
|
Milton S, Ander C, Yeheskiely E, Strömberg R. Stability of a 2′-O-(Carbamoylmethyl)adenosine-Containing Dinucleotide. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101264] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
24
|
Wenska M, Alvira M, Steunenberg P, Stenberg Å, Murtola M, Strömberg R. An activated triple bond linker enables 'click' attachment of peptides to oligonucleotides on solid support. Nucleic Acids Res 2011; 39:9047-59. [PMID: 21795380 PMCID: PMC3203603 DOI: 10.1093/nar/gkr603] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 07/05/2011] [Accepted: 07/06/2011] [Indexed: 11/13/2022] Open
Abstract
A general procedure, based on a new activated alkyne linker, for the preparation of peptide-oligonucleotide conjugates (POCs) on solid support has been developed. With this linker, conjugation is effective at room temperature (RT) in millimolar concentration and submicromolar amounts. This is made possible since the use of a readily attachable activated triple bond linker enhances the Cu(I) catalyzed 1,3-dipolar cycloaddition ('click' reaction). The preferred scheme for conjugate preparation involves sequential conjugation to oligonucleotides on solid support of (i) an H-phosphonate-based aminolinker; (ii) the triple bond donor p-(N-propynoylamino)toluic acid (PATA); and (iii) azido-functionalized peptides. The method gives conversion of oligonucleotide to the POC on solid support, and only involves a single purification step after complete assembly. The synthesis is flexible and can be carried out without the need for specific automated synthesizers since it has been designed to utilize commercially available oligonucleotide and peptide derivatives on solid support or in solution. Methodology for the ready conversion of peptides into 'clickable' azidopeptides with the possibility of selecting either N-terminus or C-terminus connection also adds to the flexibility and usability of the method. Examples of synthesis of POCs include conjugates of oligonucleotides with peptides known to be membrane penetrating and nuclear localization signals.
Collapse
Affiliation(s)
- Malgorzata Wenska
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, SE-141 83 Huddinge, Sweden
| | | | | | | | | | - Roger Strömberg
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, SE-141 83 Huddinge, Sweden
| |
Collapse
|
25
|
Towards artificial metallonucleases for gene therapy: recent advances and new perspectives. Future Med Chem 2011; 3:1935-66. [DOI: 10.4155/fmc.11.139] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The process of DNA targeting or repair of mutated genes within the cell, induced by specifically positioned double-strand cleavage of DNA near the mutated sequence, can be applied for gene therapy of monogenic diseases. For this purpose, highly specific artificial metallonucleases are developed. They are expected to be important future tools of modern genetics. The present state of art and strategies of research are summarized, including protein engineering and artificial ‘chemical’ nucleases. From the results, we learn about the basic role of the metal ions and the various ligands, and about the DNA binding and cleavage mechanism. The results collected provide useful guidance for engineering highly controlled enzymes for use in gene therapy.
Collapse
|
26
|
Kuzuya A, Tanaka K, Komiyama M. Photoswitching of site-selective RNA scission by sequential incorporation of azobenzene and acridine residues in a DNA oligomer. J Nucleic Acids 2011; 2011:162452. [PMID: 21941627 PMCID: PMC3177363 DOI: 10.4061/2011/162452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 07/06/2011] [Indexed: 11/20/2022] Open
Abstract
Photoresponsive systems for site-selective RNA scission have been prepared by combining Lu(III) ions with acridine/azobenzene dual-modified DNA. The modified DNA forms a heteroduplex with substrate RNA, and the target phosphodiester linkages in front of the acridine residue is selectively activated so that Lu(III) ion rapidly cleaves the linkage. Azobenzene residue introduced adjacent to the acridine residue acts as a photoresponsive switch, which triggers the site-selective scission upon UV irradiation. A trans isomer of azobenzene efficiently suppresses the scission, whereas the cis isomer formed by UV irradiation hardly affects the scission. As a result, 1.7-2.4-fold acceleration of the cleavage was achieved simply by irradiating UV for 3 min to the mixture prior to the reaction. Considering the yield of photoisomerization, the intrinsic activity of a cis isomer is up to 14.5-fold higher than that of the trans isomer.
Collapse
Affiliation(s)
- Akinori Kuzuya
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Chemistry and Materials Engineering, Kansai University, 3-3-35 Kamiyamate-cho, Suita, Osaka 564-8680, Japan
| | - Keita Tanaka
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Makoto Komiyama
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| |
Collapse
|
27
|
Wang MQ, Liu JL, Wang JY, Zhang DW, Zhang J, Streckenbach F, Tang Z, Lin HH, Liu Y, Zhao YF, Yu XQ. Site-selective DNA hydrolysis induced by a metal-free peptide nucleic acid-cyclen conjugate. Chem Commun (Camb) 2011; 47:11059-61. [PMID: 21901188 DOI: 10.1039/c1cc14185f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A metal-free artificial restriction DNA cutter which is composed of cyclen and classical peptide nucleic acid (PNA) was synthesized. Analysis of DNA cleavage products indicates the site-selective hydrolysis.
Collapse
Affiliation(s)
- Ming-Qi Wang
- Key Laboratory of Green Chemistry and Technology (Ministry of Education), College of Chemistry, Sichuan University, Chengdu, 610064, PR China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Gaglione M, Milano G, Chambery A, Moggio L, Romanelli A, Messere A. PNA-based artificial nucleases as antisense and anti-miRNA oligonucleotide agents. MOLECULAR BIOSYSTEMS 2011; 7:2490-9. [PMID: 21623442 DOI: 10.1039/c1mb05131h] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Because of its interesting chemical, physical and biological properties, Peptide Nucleic Acid (PNA) has attracted major attention in molecular biology, for diagnostics purposes and development of biosensors. PNAs have become candidates for gene therapeutic drugs in ANTISENSE (AO) strategy with favorable in vivo biochemical properties. Recently, antisense PNA oligonucleotides have been described in anti-miRNA approach (AMO). We propose PNA-based nucleases as AO and AMO agents. We report the design, synthesis and characterization of two kinds of artificial nucleases composed of a PEG-PNA-PEG domain conjugated to HGG·Cu (A) and DETA (B) as well known cleavage sites. Qualitative (MALDI-TOF) and quantitative (HTS) assays were planned to study nuclease activity of constructs A and B on RNA-3'-FAM target sequence. The results have highlighted the best performance of nuclease B and the relevance of the PEG spacer, in particular for conjugate A, in terms of efficiency of the cleavage, suggesting that conjugates A and B also act as potential antisense and anti-miRNA agents.
Collapse
Affiliation(s)
- M Gaglione
- Environmental Sciences Department, SUN, 81100-Caserta, Italy
| | | | | | | | | | | |
Collapse
|
29
|
Gasser G, Sosniak AM, Metzler-Nolte N. Metal-containing peptide nucleic acid conjugates. Dalton Trans 2011; 40:7061-76. [PMID: 21541385 DOI: 10.1039/c0dt01706j] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Peptide Nucleic Acids (PNAs) are non-natural DNA/RNA analogues with favourable physico-chemical properties and promising applications. Discovered nearly 20 years ago, PNAs have recently re-gained quite a lot of attention. In this Perspective article, we discuss the latest advances on the preparation and utilisation of PNA monomers and oligomers containing metal complexes. These metal- conjugates have found applications in various research fields such as in the sequence-specific detection of nucleic acids, in the hydrolysis of nucleic acids and peptides, as radioactive probes or as modulators of PNA·DNA hybrid stability, and last but not least as probes for molecular and cell biology.
Collapse
Affiliation(s)
- Gilles Gasser
- Institute of Inorganic Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
| | | | | |
Collapse
|
30
|
Murtola M, Zaramella S, Yeheskiely E, Strömberg R. Cationic peptides that increase the thermal stabilities of 2'-O-MeRNA/RNA duplexes but do not affect DNA/DNA melting. Chembiochem 2011; 11:2606-12. [PMID: 21110373 DOI: 10.1002/cbic.201000324] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Several different cationic nonapeptides have been synthesized and investigated with respect to how they can influence the thermal melting of 2'-O-methylRNA/RNA and DNA/DNA duplexes. Each peptide has a C-terminal L-phenylalanine unit and is otherwise uniformly composed of a sequence of a specific basic D-amino acid that in most cases will be largely charged at neutral pH. These N-terminal octamer stretches are composed variously of the amino acids D-lysine, D-diaminobutyric acid (D-Dab), D-diaminopropionic acid (D-Dap), or D-histidine. None of the peptides substantially affected the thermal melting of DNA/DNA duplexes, which was in sharp contrast with their effects on 2'-O-methylRNA/RNA duplexes. In particular, the peptides based on diaminopropionic and diaminobutyric acid units had strong positive effects on the melting temperatures of the 2'-O-methylRNA duplexes (up to 16 °C higher with 1 equivalent of peptide) at pH 7, whereas at pH 6 the effect was even more drastic (ΔT(m) up to +25 °C). The shorter R groups of the Dap and Dab groups appear to have a better length than lysine for enhancement of the thermal melting of the 2'-O-methylRNA/RNA duplex, an effect that is more pronounced at lower pH but substantial even at pH 7, although the Dap derivative is not likely to be fully protonated. The dramatic difference between the influence, or lack thereof, on the 2'-O-methylRNA/RNA and the DNA/DNA thermal meltings suggest that, although electrostatic interactions probably play a role, there is another major and structurally dependent component influencing the properties of the duplexes. This is also seen in the observation that the oligo-Dap and oligo-Dab peptides give greater melting point enhancements than both the lysine peptide (with a longer side chain) and a β-linked Dap peptide with a shorter side chain and a longer backbone.
Collapse
Affiliation(s)
- Merita Murtola
- Department of Biosciences and Nutrition, Unit for Bioorganic Chemistry, Karolinska Institutet, 14183 Huddinge, Sweden
| | | | | | | |
Collapse
|
31
|
Synthesis, DNA binding and cleavage studies of the copper(II) complexes of PNA-cyclen conjugates. Sci China Chem 2011. [DOI: 10.1007/s11426-010-4169-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
32
|
Murtola M, Wenska M, Strömberg R. PNAzymes that are artificial RNA restriction enzymes. J Am Chem Soc 2010; 132:8984-90. [PMID: 20545354 DOI: 10.1021/ja1008739] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
DNA-cleaving restriction enzymes are well-known tools in biomedical and biotechnological research. There are, however, no corresponding enzymes known for RNA cleavage. There has been an ongoing development of artificial ribonucleases, including some attempts at sequence selectivity. However, so far these systems have displayed modest rates of cleavage, and in most cases, the cleaver has been used in excess or in stoichiometric amounts. In the current work, we present PNA-based systems (PNAzymes) that carry a Cu(II)-2,9-dimethylphenanthroline group and that act as site and sequence specific RNases. The general basis for the systems is that the target is cleaved at a nonbase paired region (RNA bulge) which is formed in the substrate upon binding of the PNAzyme. With this copper based system, cleavage takes place at virtually only one site and with a half-life of down to 30 min under stoichiometric conditions. Efficient turnover of RNA-substrate is shown with a 100-fold excess of substrate, thus, demonstrating true enzyme behavior. In addition, alteration of the sequence in the RNA bulge or a mismatch in the base-pairing region leads to substantial decreases in rate showing both kinetic resolution and binding discrimination in the substrate selectivity. The selectivity is further demonstrated by the substrates, with two potential cleavage sites differing in only one base, are cleaved only at the site that either does not have a mismatch or is kinetically preferred. We suggest that these systems can serve as a basis for construction of RNA restriction enzymes for in vitro manipulations.
Collapse
Affiliation(s)
- Merita Murtola
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, S-14183, Huddinge, Sweden
| | | | | |
Collapse
|
33
|
Sosniak AM, Gasser G, Metzler-Nolte N. Thermal melting studies of alkyne- and ferrocene-containing PNA bioconjugates. Org Biomol Chem 2009; 7:4992-5000. [PMID: 19907791 DOI: 10.1039/b913964h] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The preparation of new metal-containing Peptide Nucleic Acids (PNAs) is currently a field of research intensively studied for various purposes, e.g. DNA biosensors. The role played by the metal centre, notably on the stability of the PNA.DNA hybrid, is obviously crucial, but has not yet been fully investigated. In this work, UV-Vis spectroscopic measurements of solutions of DNA.PNA hybrids, whose 11/12-mer PNA oligomers contained either one or two alkyne- (1) or ferrocene-containing (2) PNA monomers, were carried out to determine the effect of these monomers on the thermal stability of the hybrids (PNA: H-Gly-X-gggtc-Y-agctt-X-Lys-NH2 with X = 1 or and Y = 1 or 2 or blank position). Supplementary CD spectroscopic measurements were performed to gain insight into the structures of the PNA.DNA duplexes formed. The effect of both modified monomers was found to depend on their actual positions within the PNA sequences. Insertions at the N- or C-termini of a PNA oligomer did not change the melting temperatures (T(m) values of about 72 degrees C) of the DNA.PNA hybrids significantly. Insertion of monomers 1 or 2 in the middle of a PNA sequence induced a substantial decrease in the T(m) of the hybrids (by about 23 degrees C) when bound to the same DNA oligomer. Interestingly, it was found that the type of modification, namely alkyne or ferrocene, did not significantly influence the T(m) values in these cases. However, the thermal stability of hybrids with the DNA oligomers containing one to four additional thymines and the PNA oligomers containing the ferrocene moiety in its middle, varied significantly with the number of thymines added compared to its alkyne analogues (DeltaT(m) up to -13 degrees C). The presence of the ferrocene moiety induced a significant decrease in thermal stability of the hybrids, probably due to its bulkiness. In order to assess the effect of PNA backbone rigidity on the stability of DNA.PNA hybrids, PNA oligomers with an internal amino acid, propargylglycine (Pgl) or the dipeptide glycine-propargylglycine (Gly-Pgl), were synthesised. It was assumed that the orientation of the alkyne moiety in the Pgl-containing PNA sequence is not identical to an alkyne-containing PNA sequence, as a significantly higher T(m) value (DeltaT(m) = +10 degrees C) was measured. It is anticipated that the alkyne moiety in Pgl is not facing the DNA base and therefore does not disturb as much the neighbouring nucleobases and base-stacking of the complementary DNA, in contrast to the alkyne moiety of 1. Interestingly, no significant differences in the thermal stability of the hybrids was observed between Pgl-containing and dipeptide-containing PNA oligomers, although the former contracts the PNA backbone by three atoms.
Collapse
Affiliation(s)
- Anna M Sosniak
- Ruhr-University Bochum, Faculty of Chemistry and Biochemistry, Inorganic Chemistry I-Bioinorganic Chemistry, Universitätsstrasse 150, D-44801, Bochum, Germany
| | | | | |
Collapse
|