Determination Of The Stability Constant Of Copper-amino Acid Complexes And Their Interaction With BSA

This issue in a very simple model of capillary electrophoresis to determine of stability constants of copper and three amino acids, the method is rapid to obtain reliable results. Further, study interactions of copper-amino acid complexes and bovine serum albumin, compared the degree of quenching for bovine serum albumin.We used the capillary zone electrophoresis (CZE) technology to study the interaction between Cu(â…¡) and Alanine, Methionine, Selenomethionine (Ala, Met, SeMet), using the peak drifting model and the MATLAB software to determine and calculate the stability constant. The experiments were under 18Kv as the separation voltage, 1mmol/L imidazole as a marker, the electrophoretogram of Cu(â…¡) were good without trailing phenomenon; the determine binding constant of Cu(â…¡)-SeMet, Cu(â…¡)-Met, Cu(â…¡)-Ala complex were 10^7.35,10^13.7 and 10^7.91,10^15.85 and 10^8.17, 10^15.17, which were consistent with the literature. And the comparison between the stability constant of the three complex, the order was: Cu-Ala>Cu-Met> Cu-SeMet.Based on the above results, the interaction between copper-amino acid(Ala, Met, SeMet) complexes and BSA was studied by fluorescence spectroscopy. The results showed that the Cu(â…¡)-amino acids(Ala, Met, SeMet) complexes quenched the fluorescence of BSA and Cu(â…¡) made a leading role, which was static quenching style. Based on these results, the binding constant of Cu(â…¡)-(SeMet, Ala, Met) complex-BSA system were calculated as 4.38×10³,2.47×10³,2.61×10³L/mol, respectly. The stronger of fluorescence quenching in Cu(â…¡) amino acids(Ala, Met, SeMet) complex-BSA system in lower Cu(â…¡)-amino acids complex stable system. The weaker interaction of Cu(â…¡) amino acids(Ala, Met, SeMet) complex-BSA system were observed in Cu(â…¡) protected system by amino acids, and fluorescence quenching weakened.