[Structural parameters of charge density, macroion mobility and dissociation constants of the phosphate groups from conductivity measurements of salt free solutions of poly(U) and its salt].
Equivalent conductivity (lambda MeP) was studied for the Li+, Na+, K+, Cs+, NH4+ salts of poly(U) and for polyribouridilic acid. Concentration of the salt free solutions of poly(U) ranges from 1 . 10(-4) M-3 . 10(-3) M. Limiting equivalent conductivity (lambda 0 MeP) was obtained based on linear dependence of lambda MeP on Cp1/2 (where Cp is the concentration of nucleic phosphorus). The lambda 0 MeP values obtained were shown to increase linearly with the increase of the limiting mobility of counterion. These data were used to calculate limiting mobility of macroion (lambda p = 43 Ohm-1 Cm2 equiv-1) and parameter xi = 1.13 which characterizes charge density on a macroion. Linear dependence was shown to take place for poly(U) acid and it's salts in the Ostwald's coordinates; moreover, pK value for the phosphate groups is practically independent of the counterion's nature and equal 1.93 +/- 0.32.
D002414:Cations, Monovalent; D004553:Electric Conductivity; D007700:Kinetics; D011072:Poly U; D012492:Salts; D012996:Solutions
D002414:Cations, Monovalent; D012492:Salts; D012996:Solutions; D011072:Poly U
Strukturnyĭ parametr plotnosti zariada, podvizhnost' makroiona i konstanty dissotsiatsii fosfatnykh grupp iz izmereniĭ élektroprovodnosti bessolevykh rastvorov poli(U) i ee soleĭ.