Single-stranded nucleic acids, which carry multiple negative charges in an aqueous medium at near neutral pH, are found to induce the aggregation and self-assembly of the positively charged alkynylplatinum(II) terpyridyl complexes via electrostatic binding of the platinum complexes to the single-stranded nucleic acids, as revealed by the appearance of new UV-vis absorption and emission bands upon addition of single-stranded nucleic acids to a buffer solution of the complex. Changes in the intensity and pattern of circular dichroism (CD) spectroscopy are also observed, many of which are consistent with the assembly of the platinum complexes into helical structures, via metal...metal and pi...pi stacking interactions. The induced spectroscopic property changes are found to depend on the structural properties of the nucleic acids.
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http://dx.doi.org/10.1073/pnas.0604998104 | DOI Listing |
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January 2025
Institute of Molecular Medicine and Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine, State Key Laboratory of Oncogenes and Related Genes, Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China.
A 3D DNA spatial chip (DSC) based on an icosahedral DNA origami framework is introduced to construct customized circular single-stranded DNA (c-ssDNA) for data storage. Within the confined space of the DSC, thirty addressable location sequences extending from the framework edges are available for designing circular paths and directing the assembly of a series of information oligonucleotides for efficient ligation. This strategy is verified by constructing c-ssDNAs from up to 15 fragments to encode two poems (800 and 860 nucleotides).
View Article and Find Full Text PDFBiochem J
January 2025
School of Science, University of Waikato, Hamilton, Waikato, 3216, New Zealand.
DNA-joining by ligase and polymerase enzymes has provided the foundational tools for generating recombinant DNA and enabled the assembly of gene and genome-sized synthetic products. Xenobiotic nucleic acid (XNA) analogues of DNA and RNA with alternatives to the canonical bases, so-called 'unnatural' nucleobase pairs (UBP-XNAs), represent the next frontier of nucleic acid technologies, with applications as novel therapeutics and in engineering semi-synthetic biological organisms. To realise the full potential of UBP-XNAs, researchers require a suite of compatible enzymes for processing nucleic acids on a par with those already available for manipulating canonical DNA.
View Article and Find Full Text PDFTelomeres are hypersensitive to the formation of the common oxidative lesion 8-oxoguanine (8oxoG), which impacts telomere stability and function. OGG1 and MUTYH glycosylases initiate base excision repair (BER) to remove 8oxoG or prevent mutation. Here, we show OGG1 loss or inhibition, or MUTYH loss, partially rescues telomeric 8oxoG-induced premature senescence and associated proinflammatory responses, while loss of both glycosylases causes a near complete rescue in human fibroblasts.
View Article and Find Full Text PDFRNA Biol
December 2025
Department of Cell and Molecular Biology, Biomedical Centre, Uppsala University, Uppsala, Sweden.
We show that a small biotin-binding RNA aptamer that folds into a pseudoknot structure acts as a substrate for bacterial RNase P RNA (RPR) with and without the RNase P C5 protein. Cleavage in the single-stranded region in loop 1 was shown to depend on the presence of a RCCA-motif at the 3' end of the substrate. The nucleobase and the 2'hydroxyl at the position immediately 5' of the cleavage site contribute to both cleavage efficiency and site selection, where C at this position induces significant cleavage at an alternative site, one base upstream of the main cleavage site.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Department of Biomedical Engineering, McGill University, 3775 University Street, Montreal, Quebec H3A 2B4, Canada.
Synthetic ssDNA oligonucleotides hold great potential for various applications, including DNA aptamers, DNA digital data storage, DNA origami, and synthetic genomes. In these contexts, precise control over the synthesis of the ssDNA strands is essential for generating combinatorial sequences with user-defined parameters. Desired features for creating synthetic DNA oligonucleotides include easy manipulation of DNA strands, effective detection of unique DNA sequences, and a straightforward mechanism for strand elongation and termination.
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