Intramolecular G-quartet motifs confer nuclease resistance to a potent anti-HIV oligonucleotide
| Autor: | Michael E. Hogan, Nilabh Chaudhary, Joshua O. Ojwang, Steve Smith, Judith K. Guy-Caffey, Jeffrey S. Bishop, Paul A. Cossum, Robert F. Rando |
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| Rok vydání: | 1996 |
| Předmět: |
Models
Molecular Guanine Molecular Sequence Data Biochemistry Antiviral Agents Giant Cells chemistry.chemical_compound Structure-Activity Relationship Extracellular Computer Graphics Structure–activity relationship Humans Molecular Biology Nuclease Syncytium Base Composition biology Base Sequence Oligonucleotide Biological Transport Drug Resistance Microbial Cell Biology Thionucleotides Molecular biology Protein tertiary structure Kinetics chemistry Oligodeoxyribonucleotides Phosphodiester bond biology.protein HIV-1 Nucleic Acid Conformation HeLa Cells |
| Zdroj: | The Journal of biological chemistry. 271(10) |
| ISSN: | 0021-9258 |
| Popis: | We have identified a potentially therapeutic anti-human immunodeficiency virus (HIV)-1 oligonucleotide composed entirely of deoxyguanosines and thymidines (T30177, also known as AR177: 5'-g.tggtgggtgggtggg.t-3', where asterisk indicates phosphorothioate linkage). In acute assay systems using human T-cells, T30177 and its total phosphodiester homologue T30175 inhibited HIV-1-induced syncytium production by 50% at 0.15 and 0.3 microM, respectively. Under physiological conditions, the sequence and composition of the 17-mer favors the formation of a compact, intramolecularly folded structure dominated by two stacked guanine quartet motifs that are connected by three loops of TGs. The molecule is stabilized by the coordination of a potassium ion between the two stacked quartets. We now show that these guanine quartet-containing oligonucleotides are highly resistant to serum nucleases, with t1/2 of 5 h and >4 days for T30175 and T30177, respectively. Both oligonucleotides were internalized efficiently by cells, with intracellular concentrations reaching 5-10-fold above the extracellular levels after 24 h of incubation. In contrast, single-base mutated variants or random sequence control oligonucleotides that could not form the compactly folded structure had markedly reduced half-lives (t1/2 from approximately 3 to 7 min), low cellular uptake, and no sequence-specific anti-HIV-1 activity. These data suggest that the tertiary structure of an oligonucleotide is a key determinant of its nuclease resistance, cellular uptake kinetics, and biological efficacy. |
| Databáze: | OpenAIRE |
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