title: Determination of melting temperature and temperature melting range for DNA with multi-peak differential melting curves.
abstract: Many factors that change the temperature position and interval of the DNA helix-coil transition often also alter the shape of multi-peak differential melting curves (DMCs). For DNAs with a multi-peak DMC, there is no agreement on the most useful definition for the melting temperature, Tm, and temperature melting width, ΔT, of the entire DNA transition. Changes in Tm and ΔT can reflect unstable variation of the shape of the DMC as well as alterations in DNA thermal stability and heterogeneity. Here, experiments and computer modeling for DNA multi-peak DMCs varying under different factors allowed testing of several methods of defining Tm and ΔT. Indeed, some of the methods give unreasonable "jagged" Tm and ΔT dependences on varying relative concentration of DNA chemical modifications (rb), [Na(+)], and GC content. At the same time, Tm determined as the helix-coil transition average temperature, and ΔT, which is proportional to the average absolute temperature deviation from this temperature, are suitable to characterize multi-peak DMCs. They give smoothly varying theoretical and experimental dependences of Tm and ΔT on rb, [Na(+)], and GC content. For multi-peak DMCs, Tm value determined in this way is the closest to the thermodynamic melting temperature (the helix-coil transition enthalpy/entropy ratio).
authors: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141 Minsk, Belarus; Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan. Electronic address: lando@iboch.bas-net.by.
authors: Dmitri Y
authors: DY
authors: Lando
authors: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141 Minsk, Belarus.
authors: Alexander S
authors: AS
authors: Fridman
authors: Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan.
authors: Chun-Ling
authors: CL
authors: Chang
authors: Department of Physics, Yerevan State University, 0025 Yerevan, Armenia.
authors: Inessa E
authors: IE
authors: Grigoryan
authors: Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141 Minsk, Belarus.
authors: Elena N
authors: EN
authors: Galyuk
authors: Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan.
authors: Oleg N
authors: ON
authors: Murashko
authors: Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan.
authors: Chun-Chung
authors: CC
authors: Chen
authors: Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan. Electronic address: huck@phys.sinica.edu.tw.
authors: Chin-Kun
authors: CK
authors: Hu
mesh_terms: D000818:Animals; D001482:Base Composition; D002414:Cations, Monovalent / Q000737:chemistry; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D012964:Sodium / Q000737:chemistry; D013816:Thermodynamics; D044366:Transition Temperature
chemical_list: D002414:Cations, Monovalent; D004247:DNA; C427203:calf thymus DNA; D012964:Sodium
keywords: Calf thymus DNA; DNA melting temperature; DNA temperature melting range; High-resolution melting profiles; Plasmid DNA