Conformational changes in 6 MeV electron beam irradiated aqueous bovine serum albumin.

Abstract

Understanding the folding and unfolding mechanism of the protein is not only crucial in applications like biomedical, pharmaceutical, tissue engineering but also to the food industry. In the present study, an electron beam with 6 MeV energy derived from the Microtron accelerator was utilized to irradiate the aqueous solution of bovine serum albumin (BSA) at fluences of 5 × 10¹⁴ and 10 × 10¹⁴ e^-/cm². The control and irradiated BSA solutions were analyzed using UV-visible and FTIR spectroscopy. UV-visible spectroscopy showed a hyperchromic red shift in 235 nm (π → π*) and a blue shift in 268 nm (n → π*) bands with increasing fluence. Changes in aromatic acid residues of the proteins tertiary structure were observed from the 2nd derivative of absorbance spectra. FTIR spectra revealed a decrease in peak area corresponding to β-turns (21.80 to 15.50 %), and random coil (41.30 to 28.80 %) and increase in peak area was observed for β-sheet (29.25 to 35.40 %). These findings reveal the conformal changes in the electron irradiated BSA. Further, a decrease in the interfacial tension at the air/water interface suggests increase in hydrophobicity of the aqueous solution with fluence.