Effects of Temperature and Common Ions on Binding of Puerarin to BSA

The effects of temperature and common ions on binding of puerarin to bovine serum albumin (BSA) are investigated. The binding constants (K (a)) between puerarin and BSA are 1.13x10(4) La <...mol(-1) (20 A degrees C) and 1.54x10(4) La <...mol(-1) (30 A degrees C), and the number of binding sites (n) is (0.95 +/- 0.02). However, at a higher temperature (40 A degrees C) the stability of the puerarin-BSA system decreases, which results in a lower binding constant (1.58x10(3) La <...mol(-1)) and number of binding sites (n=0.73) of the puerarin-BSA system. However, the presence of Cu2+ and Fe3+ ions increases the binding constants and the number of binding sites in the puerarin-BSA complex.