Effect of MeV proton irradiation on bovine serum albumin molecule

1.5-MeV H+ was used to irradiate dry bovine serum albumin (BSA) molecule membranes with a thickness of 1.9 mg/cm2. The irradiation fluence ranged from 6 × 1012 to 4 × 1014 ions/cm2. By matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) changes of the molecule mass of the sample were measured. Samples immersed in heavy water were investigated by Fourier transform infrared spectroscopy (FTIR), analyzing the fraction of different secondary structures from the amide I band by Gaussian-curve fitting. MALDI-TOF results show that the BSA molecule peak disappeared when the ion fluence is higher than 6 × 1013 ions/cm2. PTIR spectra analyses show that proton traversal change the molecular structure and composition significantly.