Kinetic study of the addressed modification by hemin derivatives of oligonucleotides.

Kinetics of oligonucleotide pd(TGAATGGGAAGA) modification by a hemin derivative of the complementary oligonucleotide pd(TTCCCATT) in the presence of hydrogen peroxide was investigated. The treatment of experimental data permitted to evaluate the association and rate constants at 25 degrees C: Kx = (3.40 +/- 0.38) x 10(5) M-1 (association constant of the reagent with the target), kd = 152 +/- 6 M-1 min-1 (degradation constant of the hemin group of the reagent in a parallel reaction), ko = 51.0 +/- 1.7 M-1 min-1 (target modification constant in the reactive duplex). The modification of DNA is incomplete due to competition of the modification reaction with the degradation of the hemin group of the reagent in a parallel reaction.