Interactions between metal ions and DNA

84 years elapsed between the announcements of the periodic table and that of the DNA double helix in 1953, and the two have been combined in many ways since then. In this chapter an outline of the fundamentals of DNA structure leads into a range of examples showing how the natural magnesium and potassium ions found in nature can be substituted in a diversity of applications. The dynamic structures found in nature have been studied in the more controlled but artificial environment of the DNA crystal using examples from sodium to platinum and also in a range of DNA-binding metal complexes. While NMR is an essential technique for studying nucleic acid structure and conformation, most of our knowledge of metal ion binding has come from X-ray crystallography. These days the structures studied, and therefore also the diversity of metal binding, go beyond the double helix to triplexes, hairpin loops, junctions and quadruplexes, and the chapter describes briefly how these pieces fit into the DNA jigsaw. In a final section, the roles of metal cations in the crystallisation of new DNA structures are discussed, along with an introduction to the versatility of the periodic table of absorption edges for nucleic acid structure determination

Studies on the hydrolytic stability of 2?-fluoroarabinonucleic acid (2?F-ANA)

The stability of 2'-deoxy-2'-fluoroarabinonucleic acid (2'F-ANA) to hydrolysis under acidic and basic conditions was compared to that of DNA, RNA and 2'F-RNA. In enzyme-free simulated gastric fluid (pH approximately 1.2), 2'F-ANA was found to have dramatically increased stability (virtually no cleavage observed after 2 days) with respect to both DNA (t(1/2) approximately 2 min) and RNA (t(1/2) approximately 3 h (PO) or 3 days (PS)). These results were observed for both phosphodiester and phosphorothioate backbones and with multiple mixed-base sequences. Under basic conditions, 2'F-ANA also showed good stability. In 1 M NaOH at 65 degrees C, 2'F-ANA had a t(1/2) of approximately 20 h, while RNA was entirely degraded in a few minutes. Furthermore, the nuclease cleavage of phosphorothioate 2'F-ANA and DNA by snake venom phosphodiesterase was studied in detail. One diastereomer of the PS-2'F-ANA linkage was found to be much more vulnerable to enzymatic cleavage than the other, which is parallel to the properties observed for PS-DNA. Additional studies of 2'F-ANA-containing oligonucleotides are warranted based on the excellent stability properties described her

infoINHALER - Utilización de medicamentos y dispositivos complejos en atención farmacéutica: sistemas de inhalación

infoINHALER - Utilización de medicamentos y dispositivos complejos en atención farmacéutica: sistemas de inhalaciónPatrocinador: Universitat de Barcelona - Programa de Millora i Innovació Docent. Accions Especials 200

infoINHALER - Utilización de medicamentos y dispositivos complejos en atención farmacéutica: sistemas de inhalación

infoINHALER - Utilización de medicamentos y dispositivos complejos en atención farmacéutica: sistemas de inhalaciónPatrocinador: Universitat de Barcelona - Programa de Millora i Innovació Docent. Accions Especials 200

infoINHALER - Utilización de medicamentos y dispositivos complejos en atención farmacéutica: sistemas de inhalación

Des del 12 de gener de 2021, desapareix el complement Flash d'Adobe i no s'executa amb cap navegador. Sota la vostra responsabilitat, podeu descarregar un visor per poder executar al vostre equip qualsevol fitxer .swf. Podeu seguir les indicacions que trobareu al web següent: https://bit.ly/3zOsyl9infoINHALER - Utilización de medicamentos y dispositivos complejos en atención farmacéutica: sistemas de inhalaciónPatrocinador: Universitat de Barcelona - Programa de Millora i Innovació Docent. Accions Especials 200