Binding citrate/DNA in presence of divalent cations - Potential mimicry ofacidic peptides/DNA interactions

Citric acid whose structure is comparable to that of small acidic peptides, can bind to DNA in the presence of divalent cations (Cu2+, Fe2+, Zn2+, Mg2 +). Citrate-DNA interaction occurs also in a cell homogenate and in this ex perimental model too requires the presence of natural divalent cations. In fact the addition of 2 mM EDTA to cell homogenate strongly decreases the DN A-citrate binding. The results demonstrate that divalent cations can act as bridges between two acidic molecules and that citric acid can mimic the st ructure of acidic peptides.