1
|
Liu Y, Wan L, Ngai CK, Wang Y, Lam SL, Guo P. Structures and conformational dynamics of DNA minidumbbells in pyrimidine-rich repeats associated with neurodegenerative diseases. Comput Struct Biotechnol J 2023; 21:1584-1592. [PMID: 36874156 PMCID: PMC9975016 DOI: 10.1016/j.csbj.2023.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/05/2023] [Accepted: 02/05/2023] [Indexed: 02/10/2023] Open
Abstract
Expansions of short tandem repeats (STRs) are associated with approximately 50 human neurodegenerative diseases. These pathogenic STRs are prone to form non-B DNA structure, which has been considered as one of the causative factors for repeat expansions. Minidumbbell (MDB) is a relatively new type of non-B DNA structure formed by pyrimidine-rich STRs. An MDB is composed of two tetraloops or pentaloops, exhibiting a highly compact conformation with extensive loop-loop interactions. The MDB structures have been found to form in CCTG tetranucleotide repeats associated with myotonic dystrophy type 2, ATTCT pentanucleotide repeats associated with spinocerebellar ataxia type 10, and the recently discovered ATTTT/ATTTC repeats associated with spinocerebellar ataxia type 37 and familial adult myoclonic epilepsy. In this review, we first introduce the structures and conformational dynamics of MDBs with a focus on the high-resolution structural information determined by nuclear magnetic resonance spectroscopy. Then we discuss the effects of sequence context, chemical environment, and nucleobase modification on the structure and thermostability of MDBs. Finally, we provide perspectives on further explorations of sequence criteria and biological functions of MDBs.
Collapse
Affiliation(s)
- Yuan Liu
- South China Advanced Institute for Soft Matter Science and Technology, School of Emergent Soft Matter, South China University of Technology, Guangzhou, Guangdong 510640, China
| | - Liqi Wan
- School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Cheuk Kit Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Yang Wang
- Zhejiang Cancer Hospital, Institute of Basic Medicine and Cancer (IBMC) Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China
| | - Pei Guo
- Zhejiang Cancer Hospital, Institute of Basic Medicine and Cancer (IBMC) Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China
| |
Collapse
|
2
|
Wan L, Yi J, Lam SL, Lee HK, Guo P. 5-Methylcytosine Substantially Enhances the Thermal Stability of DNA Minidumbbells. Chemistry 2021; 27:6740-6747. [PMID: 33501691 DOI: 10.1002/chem.202005410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Indexed: 11/07/2022]
Abstract
Minidumbbell (MDB) is a recently identified non-B DNA structure that has been proposed to associate with genetic instabilities. It also serves as a functional structural motif in DNA nanotechnology. DNA molecular switches constructed using MDBs show instant and complete structural conversions with easy manipulations. The availability of stable MDBs can broaden their applications. In this work, we found that substitutions of cytosine with 5-methylcytosine could lead to a significant enhancement in the thermal stabilities of MDBs. Consecutive methylations of cytosine in MDBs brought about cumulative stabilization with a drastic increase in the melting temperature by 23 °C. NMR solution structures of two MDBs containing 5-methylcytosine residues have been successfully determined and revealed that the enhanced stabilities resulted primarily from favorable hydrophobic contacts, more stable base pairs and enhanced base-base stackings involving the methyl group of 5-methylcytosine.
Collapse
Affiliation(s)
- Liqi Wan
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Jie Yi
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong, 510006, China
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Hung Kay Lee
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Pei Guo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong, 510006, China
| |
Collapse
|
3
|
Ngai CK, Lam SL, Lee HK, Guo P. High-Resolution Structures of DNA Minidumbbells Comprising Type II Tetraloops with a Purine Minor Groove Residue. J Phys Chem B 2020; 124:5131-5138. [PMID: 32484672 DOI: 10.1021/acs.jpcb.0c03163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Minidumbbell (MDB) is a newly discovered DNA structure formed by native sequences, which serves as a possible structural intermediate causing repeat expansion mutations in the genome and also a functional structural motif in constructing DNA-based molecular switches. Until now, all the reported MDBs containing two adjacent type II tetraloops were formed by pyrimidine-rich sequences 5'-YYYR YYYR-3' (Y and R represent pyrimidine and purine, respectively), wherein the second and sixth residues folded into the minor groove and interacted with each other. In this study, we have conducted a high-resolution nuclear magnetic resonance (NMR) spectroscopic investigation on alternative MDB-forming sequences and discovered that an MDB could also be formed stably with a purine in the minor groove, which has never been observed in any previously reported DNA type II tetraloops. Our refined NMR solution structures of the two MDBs formed by 5'-CTTG CATG-3' and 5'-CTTG CGTG-3' reveal that the sixth purine residue was driven into the minor groove via base-base stacking with the second thymine residue and adenine stacked better than guanine. The results of our present research work expand the sequence criteria for the formation of MDBs and shed light to explore the significance of MDBs.
Collapse
Affiliation(s)
- Cheuk Kit Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Hung Kay Lee
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Pei Guo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, Guangdong 510006, China
| |
Collapse
|
4
|
Abstract
The non-B DNA structures formed by short tandem repeats on the nascent strand during DNA replication have been proposed to be the structural intermediates that lead to repeat expansion mutations. Tetranucleotide TTTA and CCTG repeat expansions have been known to cause reduction in biofilm formation in Staphylococcus aureus and myotonic dystrophy type 2 in human, respectively. In this study, we report the first three-dimensional minidumbbell (MDB) structure formed by natural DNA sequences containing two TTTA or CCTG repeats. The formation of MDB provides possible pathways for strand slippage to occur, which ultimately leads to repair escape and thus expansion mutations. Our result here shows that MDB is a highly compact structure composed of two type II loops. In addition to the typical stabilizing interactions in type II loops, MDB shows extensive stabilizing forces between the two loops, including two distinctive modes of interactions between the minor groove residues. The formation of MDB enriches the structural diversity of natural DNA sequences, reveals the importance of loop-loop interactions in unusual DNA structures, and provides insights into novel mechanistic pathways of DNA repeat expansion mutations.
Collapse
Affiliation(s)
- Pei Guo
- Department of Chemistry, The Chinese University of Hong Kong , Shatin, New Territories, Hong Kong
| | - Sik Lok Lam
- Department of Chemistry, The Chinese University of Hong Kong , Shatin, New Territories, Hong Kong
| |
Collapse
|
5
|
Jabasini M, Ewis A, Sato Y, Nakahori Y, Baba Y. Anomalous Separation of Small Y-Chromosomal DNA Fragments on Microchip Electrophoresis. Sci Pharm 2016; 84:507-513. [PMID: 28117316 PMCID: PMC5064241 DOI: 10.3390/scipharm84030507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/13/2016] [Indexed: 11/16/2022] Open
Abstract
We investigated an anomalous DNA separation where two DNA fragments from the human Y-chromosome sY638 (64 bp) and sY592 (65 bp), with only one base pair difference, were separated. This result is abnormal since in a previous study, we found that 5 bp was the minimum difference between two DNA fragments that the microchip electrophoresis system can separate. The formation of a mini-loop in the structure of the DNA fragment of sY638 (64 bp) was strongly expected to be the reason. To investigate this, we synthesized three modified DNA fragments for sY638 (64 bp), and the modifications were in two expected locations for possible mini-loop formation. Later, the separation between sY592 (65 bp) and the three modified fragments of sY638 (64 bp) was not possible. Thus, we conclude that the formation of a mini-loop in the structure of the DNA is the reason behind this anomalous separation.
Collapse
Affiliation(s)
- Mohammad Jabasini
- Department of Pharmaceutical Information Science, Institute of Health Biosciences, The University of Tokushima, 1-78-1 Sho-machi, 770-8505 Tokushima, Japan.
- Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, 464-8603 Nagoya, Japan.
| | - Ashraf Ewis
- Department of Human Genetics Public Health, School of Medicine, The University of Tokushima, 3-18-15 Kuramoto-cho, 770-8503 Tokushima, Japan.
| | - Youichi Sato
- Department of Pharmaceutical Information Science, Institute of Health Biosciences, The University of Tokushima, 1-78-1 Sho-machi, 770-8505 Tokushima, Japan.
| | - Yutaka Nakahori
- Department of Human Genetics Public Health, School of Medicine, The University of Tokushima, 3-18-15 Kuramoto-cho, 770-8503 Tokushima, Japan.
| | - Yoshinobu Baba
- Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, 464-8603 Nagoya, Japan.
- ImPACT Research Center for Advanced Nanobiodevices., Nagoya University, Furo-cho, Chikusa-ku, 464-8603 Nagoya, Japan.
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Hayashi-cho 2217-14, 761-0395 Takamatsu, Japan.
| |
Collapse
|
6
|
Yang C, Kim E, Pak Y. Free energy landscape and transition pathways from Watson-Crick to Hoogsteen base pairing in free duplex DNA. Nucleic Acids Res 2015; 43:7769-78. [PMID: 26250116 PMCID: PMC4652778 DOI: 10.1093/nar/gkv796] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/27/2015] [Indexed: 11/20/2022] Open
Abstract
Houghton (HG) base pairing plays a central role in the DNA binding of proteins and small ligands. Probing detailed transition mechanism from Watson–Crick (WC) to HG base pair (bp) formation in duplex DNAs is of fundamental importance in terms of revealing intrinsic functions of double helical DNAs beyond their sequence determined functions. We investigated a free energy landscape of a free B-DNA with an adenosine–thymine (A–T) rich sequence to probe its conformational transition pathways from WC to HG base pairing. The free energy landscape was computed with a state-of-art two-dimensional umbrella molecular dynamics simulation at the all-atom level. The present simulation showed that in an isolated duplex DNA, the spontaneous transition from WC to HG bp takes place via multiple pathways. Notably, base flipping into the major and minor grooves was found to play an important role in forming these multiple transition pathways. This finding suggests that naked B-DNA under normal conditions has an inherent ability to form HG bps via spontaneous base opening events.
Collapse
Affiliation(s)
- Changwon Yang
- Department of Chemistry and Institute of Functional Materials, Pusan National University, Busan 609-735, South Korea
| | - Eunae Kim
- College of Pharmacy, Chosun University, Gwangju 501-759, South Korea
| | - Youngshang Pak
- Department of Chemistry and Institute of Functional Materials, Pusan National University, Busan 609-735, South Korea
| |
Collapse
|
7
|
Zhou H, Hintze BJ, Kimsey IJ, Sathyamoorthy B, Yang S, Richardson JS, Al-Hashimi HM. New insights into Hoogsteen base pairs in DNA duplexes from a structure-based survey. Nucleic Acids Res 2015; 43:3420-33. [PMID: 25813047 PMCID: PMC4402545 DOI: 10.1093/nar/gkv241] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/01/2015] [Indexed: 11/14/2022] Open
Abstract
Hoogsteen (HG) base pairs (bps) provide an alternative pairing geometry to Watson-Crick (WC) bps and can play unique functional roles in duplex DNA. Here, we use structural features unique to HG bps (syn purine base, HG hydrogen bonds and constricted C1'-C1' distance across the bp) to search for HG bps in X-ray structures of DNA duplexes in the Protein Data Bank. The survey identifies 106 A•T and 34 G•C HG bps in DNA duplexes, many of which are undocumented in the literature. It also uncovers HG-like bps with syn purines lacking HG hydrogen bonds or constricted C1'-C1' distances that are analogous to conformations that have been proposed to populate the WC-to-HG transition pathway. The survey reveals HG preferences similar to those observed for transient HG bps in solution by nuclear magnetic resonance, including stronger preferences for A•T versus G•C bps, TA versus GG steps, and also suggests enrichment at terminal ends with a preference for 5'-purine. HG bps induce small local perturbations in neighboring bps and, surprisingly, a small but significant degree of DNA bending (∼14°) directed toward the major groove. The survey provides insights into the preferences and structural consequences of HG bps in duplex DNA.
Collapse
Affiliation(s)
- Huiqing Zhou
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Bradley J Hintze
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | - Isaac J Kimsey
- Department of Biochemistry, Duke University, Durham, NC 27710, USA
| | | | - Shan Yang
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA
| | | | - Hashim M Al-Hashimi
- Department of Biochemistry, Duke University, Durham, NC 27710, USA Department of Chemistry, Duke University, Durham, NC 27708, USA
| |
Collapse
|
8
|
Escaja N, Gómez-Pinto I, Viladoms J, Pedroso E, González C. The effect of loop residues in four-stranded dimeric structures stabilized by minor groove tetrads. Org Biomol Chem 2014; 11:4804-10. [PMID: 23764570 DOI: 10.1039/c3ob40741a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Some DNA oligonucleotides can fold back and self-associate forming dimeric structures stabilized by intermolecular base pairs. The resulting antiparallel dimer is a tightly packed four-stranded structure formed by a core of minor groove tetrads connected by short loops of unpaired nucleotides. We have explored the sequential requirements for the loop residues and have found that this family of structures is only stable with one- and two-residue loops, with the stability of the former ones being only marginal. Two-residue loops with purines in the first position give rise to the most stable structures due to their enhanced stacking interaction with the adjacent minor groove tetrad. On the other hand, pyrimidines confer more stability than purines in the second position of the loop.
Collapse
Affiliation(s)
- Núria Escaja
- Departament de Química Orgànica, Universitat de Barcelona, C/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | | | | | | | | |
Collapse
|
9
|
El-Sagheer AH, Brown T. Synthesis of alkyne- and azide-modified oligonucleotides and their cyclization by the CuAAC (click) reaction. ACTA ACUST UNITED AC 2009; Chapter 4:Unit 4.33. [PMID: 19085984 DOI: 10.1002/0471142700.nc0433s35] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reaction has been used to synthesize cyclic mini-DNA duplexes. The reaction is carried out on 5'-alkyne-3'-azide-labeled hairpin loop oligonucleotides and proceeds in high yield under mild conditions in as little as 5 min. The resultant duplexes have very high thermal stability and their CD spectra are characteristic of normal B-DNA.
Collapse
Affiliation(s)
- Afaf H El-Sagheer
- School of Chemistry, University of Southampton, Highfield Southampton, UK
| | | |
Collapse
|
10
|
El-Sagheer AH, Kumar R, Findlow S, Werner JM, Lane AN, Brown T. A very stable cyclic DNA miniduplex with just two base pairs. Chembiochem 2008; 9:50-2. [PMID: 18058775 DOI: 10.1002/cbic.200700538] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Afaf H El-Sagheer
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | | | | | | | | | | |
Collapse
|
11
|
Escaja N, Gómez-Pinto I, Viladoms J, Rico M, Pedroso E, González C. Induced-fit recognition of DNA by small circular oligonucleotides. Chemistry 2007; 12:4035-42. [PMID: 16607659 DOI: 10.1002/chem.200600050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have investigated the molecular interaction between cyclic and linear oligonucleotides. We have found that short cyclic oligonucleotides can induce hairpinlike structures in linear DNA fragments. By using NMR and CD spectroscopy we have studied the interaction of the cyclic oligonucleotide d<pCCTTCGGT> with d<pCAGTCCCT>, as well as with its two linear analogs d(GTCCCTCA) and d(CTCAGTCC). Here we report the NMR structural study of these complexes. Recognition between these oligonucleotides occurs through formation of four intermolecular Watson-Crick base pairs. The three-dimensional structure is stabilized by two tetrads, formed by facing the minor-groove side of the Watson-Crick base pairs. Overall, the structure is similar to those observed previously in other quadruplexes formed by minor-groove alignment of Watson-Crick base pairs. However, in this case the complexes are heterodimeric and are formed by two different tetrads (G:C:A:T and G:C:G:C). These complexes represent a new model of DNA recognition by small cyclic oligonucleotides, increasing the number of potential applications of these interesting molecules.
Collapse
Affiliation(s)
- Núria Escaja
- Departament de Química Orgànica, Universitat de Barcelona, Martí I Franquès 1-11, 08028 Barcelona, Spain
| | | | | | | | | | | |
Collapse
|
12
|
Escaja N, Gómez-Pinto I, Pedroso E, Gonzalez C. Four-Stranded DNA Structures Can Be Stabilized by Two Different Types of Minor Groove G:C:G:C Tetrads. J Am Chem Soc 2007; 129:2004-14. [PMID: 17260988 DOI: 10.1021/ja066172z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Four-stranded nucleic acid structures are central to many processes in biology and in supramolecular chemistry. It has been shown recently that four-stranded DNA structures are not only limited to the classical guanine quadruplex but also can be formed by tetrads resulting from the association of Watson-Crick base pairs. Such an association may occur through the minor or the major groove side of the base pairs. Structures stabilized by minor groove tetrads present distinctive features, clearly different from the canonical guanine quadruplex, making these quadruplexes a unique structural motif. Within our efforts to study the sequence requirements for the formation of this unusual DNA motif, we have determined the solution structure of the cyclic oligonucleotide dpCCGTCCGT by two-dimensional NMR spectroscopy and restrained molecular dynamics. This molecule self-associates, forming a symmetric dimer stabilized by two G:C:G:C tetrads with intermolecular G-C base pairs. Interestingly, although the overall three-dimensional structure is similar to that found in other cyclic and linear oligonucleotides of related sequences, the tetrads that stabilize the structure of dpCCGTCCGT are different to other minor groove G:C:G:C tetrads found earlier. Whereas in previous cases the G-C base pairs aligned directly, in this new tetrad the relative position of the two base pairs is slipped along the axis defined by the base pairs. This is the first time that a quadruplex structure entirely stabilized by slipped minor groove G:C:G:C tetrads is observed in solution or in the solid state. However, an analogous arrangement of G-C base pairs occurs between the terminal residues of contiguous duplexes in some DNA crystals. This structural polymorphism between minor groove GC tetrads may be important in stabilization of higher order DNA structures.
Collapse
Affiliation(s)
- Núria Escaja
- Instituto de Química Física "Rocasolano", CSIC, C/, Serrano 119, 28006 Madrid, Spain
| | | | | | | |
Collapse
|
13
|
Gómez-Pinto I, Marchán V, Gago F, Grandas A, González C. Solution structure and stability of a disulfide cross-linked nucleopeptide duplex. Chem Commun (Camb) 2004:2558-9. [PMID: 14594279 DOI: 10.1039/b307300a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
NMR methods are used to study the structure and stability of the duplex formed by the nucleopeptide [Ac-Cys-Gly-Ala-Hse(p3'dGCATGC)-Ala-OH]2[S-S], in which the oligonucleotide is self-complementary and the cysteine residues of the two peptide chains form a disulfide bridge; thermal transitions and NMR-derived structural calculations are consistent with a 3-D structure in which the oligonucleotide forms a standard B-DNA helix without significant distortions; the peptide chains are relatively disordered in solution and lie in the minor groove of the DNA helix; this nucleopeptide duplex exhibits a high melting temperature, indicating that peptide-oligonucleotide conjugates containing cysteines are suitable molecules to establish cross-links between DNA strands and stabilize the duplex.
Collapse
Affiliation(s)
- Irene Gómez-Pinto
- Instituto de Química Física Rocasolano, C/Serrano 119, 28006 Madrid, Spain
| | | | | | | | | |
Collapse
|
14
|
Edupuganti OP, Defrancq E, Dumy P. Head-to-tail oxime cyclization of oligodeoxynucleotides for the efficient synthesis of circular DNA analogues. J Org Chem 2004; 68:8708-10. [PMID: 14575507 DOI: 10.1021/jo035064h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A convenient strategy for the synthesis of the analogue of cyclic oligodeoxyribonucleotides is presented. The cyclization of the oligonucleotide was accomplished through intramolecular oxime bond formation between a 5'-oxyamine moiety and a 3'-aldehydic group.
Collapse
Affiliation(s)
- Om Prakash Edupuganti
- LEDSS, UMR CNRS 5616, ICMG FR2607, Université Joseph Fourier, BP 53, 38041 Grenoble 9, France.
| | | | | |
Collapse
|