Spectroscopic studies on the interaction between nicotinamide and bovine serum albumin

The interaction of nicotinamide (NA) and bovine serum albumin (BSA) was studied by fluorescence and absorption spectroscopy at different temperatures. The results revealed that NA caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants K-A, and the number of binding sites n, corresponding thermodynamic parameters Delta G, Delta H, Delta S between NA and BSA at different temperatures were calculated. The primary binding pattern between NA and BSA was interpreted as hydrophobic interaction. In addition, the effect of NA oil the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. The binding average distance, r between the donor (BSA) and acceptor (NA) was determined based oil the Forster's theory and it was found to be 3.1 nm. (C) 2008 Elsevier B.V. All rights reserved.