DNA as an enzyme. The effect of imidazole derivatives as cofactors and metal ions as activators or inhibitors.

摘要: Abstract Objective A highly sensitive spectrofluorometric method using dichlorofluorescin (LDCF) was employed to study the rate of electron transfer reaction in presence DNA and some imidazole derivatives. Results: In our experiments, possessed a unique enzyme like catalytic function oxidative conversion nonfluorescent LDCF fluorescent dichlorofluorescein (DCF). The enhancement associated with turn over constant: k p = 10 s −1 for cinnamoyl as cofactor. biphasic saturation curve observed when velocities were measured at fixed concentrations variable amounts carnosine. Each trends gave Scatchard values V m1 /K 3.1 × −5 m2 5.1 −6 K 2.7 M 4.2 −4 Although Ni (II) Pb induced inhibition or carnosine, metal ions such Mg (II), Cd Zn Fe caused activation DNA. rates reactions showed strong dependency on electronegativity conductivity ions, namely increase activity each ion correlated inversely electronegativities also related directly conductivities individual metal. These effects both reaction. Imidazole compounds, e.g., Histidine, N- trans along produced further enhancement. several times greater imidazole. Conclusions: This effect could provide additional evidence importance an intermediary cofactor that facilitate from site conductive chord. most guaranteed by conjugated system provided compound