Oxygen effect in the radiolysis of proteins. IV. Myoglobin.
Radiolysis of myoglobin was carried out under air and under nitrogen in phosphate buffer at pH 5 and 7. The radiation products were separated by SDS-polyacrylamide gel electrophoresis and by HPL gel chromatography with guanidine.HCl. Under nitrogen the main reaction is the aggregation caused by covalent cross-links. Under air the radiolysis leads to peptide chain scission, which is not a random process, but produces specific protein fragments. The estimated molecular weights of these fragments gave further support to the assumption that the aminoacyl-proline peptide group is the preferential breaking site. In contrast to haemoglobin, myoglobin showed nearly no radiation-induced fragmentation under nitrogen.
Department of Molecular Biophysics, University of Lódź, Poland.
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Puchała
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Schuessler
D002850:Chromatography, Gel; D003432:Cross-Linking Reagents; D004563:Electrochemistry; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry; D008970:Molecular Weight; D009211:Myoglobin / Q000737:chemistry* / Q000187:drug effects / Q000528:radiation effects*; D009584:Nitrogen / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology*; D010446:Peptide Fragments / Q000737:chemistry
D003432:Cross-Linking Reagents; D009211:Myoglobin; D010446:Peptide Fragments; D017665:Hydroxyl Radical; D009584:Nitrogen; D010100:Oxygen