Effect of γ-Irradiation on the Molecular Properties of Myoglobin

Abstract

To elucidate the effect of gamma-irradiation on the molecular properties of myoglobin, the secondary and tertiary structures, as well as the molecular weight size of the protein, were examined after irradiation at various irradiation doses. Gamma-irradiation of myoglobin solutions caused the disruption of the ordered structure of the protein molecules, as well as degradation, crosslinking, and aggregation of the polypeptide chains. A SDSPAGE study indicated that irradiation caused initial fragmentation of the proteins and subsequent aggregation, due to cross-linking of the protein molecules. The effect of irradiation on the protein was more significant at lower protein concentrations. Ascorbic acid protected against the degradation and aggregation of proteins by scavenging oxygen radicals that are produced by irradiation. A circular dichroism study showed that an increase of the irradiation decreased the alpha-helical content of myoglobin with a concurrent increase of the aperiodic structure content. Fluorescence spectroscopy indicated that irradiation increased the emission intensity that was excited at 280 nm.

Peptide Structure Modifications: Effect of Radical Species Generated by Controlled Gamma Ray Irradiation Approach

“…These compounds are possibly the result of radical-radical termination, cross-linking, fragmentation reactions and/or individual changes is some amino acid residues that occurred as a consequence of the generated reactive radical species by gamma ray irradiation procedure. 4,42,43) The Fig. 4 displays collectively, the nonlinear degradation profiles found for all peptides studied in the present work.…”

Virus Inactivation Using a High Dose of Gamma-Irradiation: A Possible Approach for Safer Vaccines Against Highly Infectious Agents

“…In addition, gamma-irradiation has been shown to be associated with protein damage [11], including fragmentation due to breakage of covalent bonds within the polypeptide chain [12]. This is illustrated by excessive damage to Murine Norovirus 1 (MNV-1) capsid protein VP1 following irradiation with increased doses of gamma-rays at room temperature [13].…”

Sterilization and protection of protein in combinations of Camellia sinensis green tea extract and gamma irradiation

“…Gamma-irradiation is known to cause irreversible alterations of protein conformation at the molecular level, such as fragmentation or aggregation [25]. Lee and Song showed via sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) study, that gamma-irradiation of myoglobin in solution, first caused the disruption and then aggregation due to the cross-linking of myoglobin fragments and that degradation and aggregation could be prevented by antioxidants such as ascorbic acid [26]. Protein damages due to indirect irradiation effects could be minimized by optimization of the irradiation parameters.…”