Photolysis of Bovine Serum Albumin by near UV irradiation

Sarah Foley (1) , Angela Staicu (2) , Alexandru Pascu (2) , Mironel Enescu (1)

1 LCE - Laboratoire Chrono-environnement (UMR 6249)
2 INFLPR - National Institute for Laser, Plasma and Radiation Physics

Proteins are major biological targets for oxidative damage due to their abundance and high rates of reactions with reactive oxygen species including radicals and excited state species. This work studies the photooxidation of Bovine Serum Albumin (BSA) by singlet molecular oxygen (1O2) using Raman spectroscopy which allows the spectral changes induced by oxidation to be directly identified. The results show that these changes mainly affect the S-S and the amide Raman bands. Tri-peptides containing amino acids His, Met, Trp and Tyr whose side chains are known to preferentially react with 1O2 are also analysed allowing the specific changes associated with each amino acid to be observed and discussed within the context of the changes observed in the protein. The singlet oxygen quenching rate constants for BSA were measured using time resolved near infrared phosphorescence. It was found that the rate constants vary as a function of pD thus highlighting the effect of conformation on the process of oxidation.

Domaines: Chimie théorique et/ou physique

Sarah Foley, Angela Staicu, Alexandru Pascu, Mironel Enescu. Photolysis of Bovine Serum Albumin by near UV irradiation. XIVth European Conference on the Spectroscopy of Biological Molecules, Aug 2011, Coimbra, Portugal. ⟨hal-00933452⟩