Journal of Chemistry and Biochemistry

Spectroscopic Study of Dipicolinic Acid Interaction with Bovine Serum Albumin
Anne Okafor, Merhun Uddin, Joseph E. Ocando, Neil Jespersen, Jianwei Fan, Enju Wang

Abstract
Spectral changes of bovine serum albumin (BSA) in the presence of dipicolinic acid (DPA) were studied with UV/Vis absorption and fluorescence spectroscopy. The change in UV/vis spectra of BSA in the presence of DPA indicated the protein weakly interacting with DPA. The DPA quenching to the fluorescence of BSA leads to the calculation of the BAS-DPA association constant K of 8.9 x 104 Lmol-1 at 295 K and 4.0 x 104 Lmol-1 at 308 K. From the synchronous spectra, the results show that the tryptophan site has a greater impact on the spectral properties of BSA than the tyrosine; DPA interacts with BSA through Van der Waals force, hydrogen bonding, and electrostatic interactions. Only 40% of the tryptophan is accessible for the ionic DPA quenching.

Full Text: PDF     DOI: 10.15640/jcb.v4n1a3