Lysozyme fragmentation induced by gamma-radiolysis.
Irradiation of lysozyme in frozen states in the absence of oxygen induces specific fragmentation at defined sites along the backbone chain. This paper localizes radio-fragmentation sites by two methods. First, N-terminal sequencing of radiolysis fragments after separation by SDS-polyacrylamide gel electrophoresis and estimation of their molecular masses. Secondly, after purification of radiolysis fragments by reverse phase-HPLC and determination of their molecular mass by electro-spray-ionization mass-spectrometric analysis, combined to N-terminal sequencing and total amino acid analysis. Evidence for the breakage of the peptide bond itself (CO-NH) is given, with radio-fragmentation sites mostly found at the surface of irradiated lysozyme in solvent exposed loops and turns.
Filali-Mouhim
A
A
Hôpital Sainte-Justine, Département de Pédiatrie, Université de Montréal, Québec, Canada.
Audette
M
M
St-Louis
M
M
Thauvette
L
L
Denoroy
L
L
Penin
F
F
Chen
X
X
Rouleau
N
N
Le Caer
J P
JP
Rossier
J
J
Potier
M
M
Le Maire
M
M
D002851:Chromatography, High Pressure Liquid; D004527:Egg Proteins / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects*; D004591:Electrophoresis, Polyacrylamide Gel; D005615:Freezing; D005720:Gamma Rays; D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012996:Solutions
D004527:Egg Proteins; D012996:Solutions; D009113:Muramidase