[Show abstract][Hide abstract] ABSTRACT: The interactions between PAMAM G3.5 dendrimer, Cd2+, a complex of "PAMAM G3.5 dendrimer-Cd2+" and human serum albumin were studied by equilibrium dialysis, fluorescence quenching, fluorescence anisotropy and zeta-potential. It was found that in water one molecule of PAMAM 3.5 dendrimer can bind 38+/-9 cadmium ions with Kb=1.3+/-0.13 x 10(3). The calculated Stern-Volmer constants of albumin fluorescence quenching by Cd2+, G3.5 and the "PAMAM G3.5-Cd2+" complex were 2.2+/-0.2, 1.6+/-0.3 and 1.4+/-0.1(mmol/l)(-1), respectively. The data from the fluorescence and zeta-potential studies show that the "PAMAM G3.5-Cd2+" complex interacted much less strongly with human serum albumin than the pure dendrimer or Cd2+.
[Show abstract][Hide abstract] ABSTRACT: Binding of Cd(2+) by PAMAM 4.5 dendrimer was studied by equilibrium dialysis, isothermal titration calorimetry and zeta-potential measurement. The following binding parameters were obtained: n=23.8+/-9.5, K(b)=4.7+/-0.9x10(3) in water; and n=41.3+/-13.4, K(b)=2.1+/-0.8x10(3) in 0.15 mol/l phosphate-buffered saline. The location of the bound Cd(2+) is discussed. The interactions between bovine serum albumin, PAMAM 4.5 dendrimer and cadmium were analyzed using fluorescence and equilibrium dialysis. The competition between Cd(2+) binding to BSA and PAMAM 4.5 dendrimer was investigated. It is proposed that PAMAM 4.5 dendrimer could be successfully used for extracting Cd(2+) from aqueous solutions (environmental protection).
[Show abstract][Hide abstract] ABSTRACT: Dendrimers are new, highly branched polymers. Their specific structure gives them an ability to interact with many different molecules, also with metal ions. The interactions between dendrimer, copper ions and dendrimer-copper complex with human serum albumin were investigated using fluorescence and dialysis methods. The results demonstrate that relatively high number of copper ions which can be bound per single molecule of G3.5 PAMAM dendrimer compare with some well known metal chelators (EDTA, BAL) allow to conclude that this generation can be an efficient chelator for Cu 2+ ions in water solution and play a role in environment protection to remove these metal from aqueous reservoirs. On the other hand G3.5 dendrimers rather cannot protect the human serum albumin before a destructive influence of copper on the protein. What is more the dendrimer – copper complex generally stronger influence on the structure of human serum albumin compared to the alone copper ions.