THE NOVEL BEHAVIOR OF INTERACTIONS BETWEEN NI2-ALBUMIN( ION AND HUMANOR BOVINE SERUM)

We discovered a series of novel behaviours of interactions between Ni2 + ion and human or bovine serum albumin. Our results indicated that th ere exist two closely neighbouring identical prior binding sites in th e binding of human or bovine serum albumin with Ni2+ ions, not only on e. It is very likely that, after the binding of the first Ni2+ ion, an induced slow conformational transition happens, which leads to the bi nding of the second Ni2+ ion and shows itself as a hysteretic effect f or a process of non-enzymic protein binding with metal ions. As the co ncentrations of the 1:1 (molar ratio of Ni2+ ion to protein) system in crease, an increasing hypochromic effect is observed. Such a hypochrom ic effect has not been reported previously; however, it is in accord w ith the mechanism of dipole-dipole interactions between the electric d ipole transition moments of chromophores.