NMR studies of anticancer drug tallysomycin metal complexes and its coordination modes

Metallo-tallysomycin (an anticancer drug metal complex) recognizes specific tumor cell, and noncovalently binds to DNA base pair to cleave sequence. Anticancer drug metal complexes, zinc- and cobalt-binding tallysomycins, were synthesized and purified in order to understand the functions of metal complexes. Complete exchangeable 1H-NMR signal assignment was accomplished by optimal pH- and temperature-dependent 1H-NMR studies. In addition, a recently developed NERD(2D NOESY-1-1 echo) experiment gave a detail structural feature which is useful for NMR-based solution state structure determination of complex. Results exhibit that nitrogen atoms of β-aminoalanine, β-hydroxyhistidine, imidazole, and pyrimidine ring are the metal binding sites with a Zn(II) ion, whereas Co(III) ion can bind to one and two equivalent of tallysomycin, respectively. (author)