title: Radiation-induced reductive modifications of sulfur-containing amino acids within peptides and proteins.
abstract: The complex scenario of radical stress reactions affecting peptides/proteins can be better elucidated through the design of biomimetic studies simulating the consequences of the different free radicals attacking amino acids. In this context, ionizing radiations allowed to examine the specific damages caused by H-atoms and electrons coupled with protons, thus establishing the molecular basis of reductive radical stress. This is an innovative concept that complements the well-known oxidative stress also in view of a complete understanding of the global consequences of radical species reactivities on living systems. This review summarizes the knowledge of the chemical changes present in sulfur-containing amino acids occurring in polypeptides under reductive radical conditions, in particular the transformation of Met and Cys residues into α-amino butyric acid and alanine, respectively. Reductive radical stress causing a desulfurization process, is therefore coupled with the formation of S-centered radicals, which in turn can diffuse apart and become responsible of the damage transfer from proteins to lipids. These reductive modifications assayed in different peptide/protein sequences constitute an integration of the molecular inventories that up to now take into account only oxidative transformations. They can be useful to achieve an integrated vision of the free radical reactivities in a multifunctional system and, overall, for wider applications in the redox proteomics field.
authors: ISOF, Consiglio Nazionale delle Ricerche, 40129 Bologna, Italy. chrys@isof.cnr.it
authors: Chryssostomos
authors: C
authors: Chatgilialoglu
authors: Carla
authors: C
authors: Ferreri
authors: Armida
authors: A
authors: Torreggiani
authors: Anna Maria
authors: AM
authors: Salzano
authors: Giovanni
authors: G
authors: Renzone
authors: Andrea
authors: A
authors: Scaloni
mesh_terms: D000603:Amino Acids, Sulfur / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects*; D000818:Animals; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008954:Models, Biological; D010084:Oxidation-Reduction / Q000528:radiation effects; D018384:Oxidative Stress / Q000528:radiation effects*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D011499:Protein Processing, Post-Translational / Q000528:radiation effects*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D011839:Radiation, Ionizing
chemical_list: D000603:Amino Acids, Sulfur; D010455:Peptides; D011506:Proteins