Interstrand cross-linking of the hexadeoxynucleotide d(TACGTA) upon reaction with trans-diamminedichloroplatinum(II).

The reaction of trans-diamminedichloroplatinum(II), an inactive isomer of cisplatin, with d(TACGTA) was performed in aqueous solution, and the interstrand cross-linked adduct was isolated on a preparative scale. This adduct was characterized by 1 M thiourea treatment, atomic absorption spectroscopy, enzymatic digestion and 1H NMR as platinum coordinated to two molecules of d(TACGTA) at the N7 atom of the guanine residue. This interstrand cross-linked adduct did not form a duplex structure in the conditions where the free hexanucleotide adopts it.