title: Stabilities of duplexes and triplexes of dA19 + dT19 with alternating methylphosphonate and phosphodiester linkages.
abstract: Results from UV thermal melting, polyacrylamide gel electrophoresis and circular dichroism (CD) experimetns are used to compare stabilities of complexes formed from 1:1 and 1:2 molar ratio mixtures of dA19 or dA*P19 (alternating phosphodiester and methylphosphonate linkages on the A chain) with dT19 or dT*P19 (alternating phosphodiester and methylphosphonate linkages on the T chain). Complexes formed from 1:1 and 1:2 molar ratio mixtures of dA*P19 with dT19 are more stable than the respective unmodified 'parent' complexes, but less stable than complexes of dA*19 (17 methylphosphonates on the A chain) + dT19. At 0.1 M Na+ complexes containing dT*P19 are less stable than those with dT19, yet more stable than complexes containing the highly modified dT*19 (17 methylphosphonates on the T chain). A value of 2.6 kcal/mol base triplets is calculated for delta H of dA19.2dT19-->dA19.dT19+dT19.
authors: Department of Chemistry, Georgia State University, Atlanta 30303-3083.
authors: L
authors: L
authors: Kibler-Herzog
authors: G
authors: G
authors: Zon
authors: G
authors: G
authors: Whittier
authors: S
authors: S
authors: Mizan
authors: W D
authors: WD
authors: Wilson
mesh_terms: D002942:Circular Dichroism; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D016376:Oligonucleotides, Antisense / Q000138:chemical synthesis / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
chemical_list: D016376:Oligonucleotides, Antisense; D009943:Organophosphorus Compounds; C032627:methylphosphonic acid