Collagen degradation by superoxide anion in pulse and gamma radiolysis.
Delipidated collagen fibrils reconstituted from acid-soluble calf skin collagen, suspended in 50 mM phosphate buffer, pH 7.4, containing 100 mM sodium formate, were submitted to pulse radiolysis in Febetron devices or to gamma radiolysis in a 60Co irradiator. A collagen degradation process was found. The kinetics of this degradation was followed by evaluation of the amount of 4-hydroxyproline present in the small peptides liberated during the irradiation period. The yield of 4-hydroxyproline small peptides was low (0.1 mol/100 eV for an initial collagen concentration 3.2 microM). It increased linearly with the dose of irradiation and the concentration of collagen in suspension. The kinetic competition between O2-. dismutation and O2-. reaction with collagen was studied by pulse radiolysis at several concentrations of collagen. A value of the kinetic constant of k(O2-. + collagen) = 4.8 . 10(6) mol-1.l.s-1 was determined.
Monboisse
J C
JC
Laboratory of Biochemistry, CNRS UA 610, UFR Medicine, Reims, France.
Gardès-Albert
M
M
Randoux
A
A
Borel
J P
JP
Ferradini
C
C
D000818:Animals; D000838:Anions; D002417:Cattle; D003037:Cobalt Radioisotopes; D003094:Collagen / Q000378:metabolism*; D003676:Deferoxamine / Q000494:pharmacology; D005720:Gamma Rays; D006909:Hydroxyproline / Q000378:metabolism; D007700:Kinetics; D004369:Pentetic Acid / Q000494:pharmacology; D010446:Peptide Fragments / Q000378:metabolism; D011675:Pulse Radiolysis; D012867:Skin / Q000032:analysis; D013057:Spectrum Analysis; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*
D000838:Anions; D003037:Cobalt Radioisotopes; D010446:Peptide Fragments; D013481:Superoxides; D004369:Pentetic Acid; D003094:Collagen; D013482:Superoxide Dismutase; D003676:Deferoxamine; D006909:Hydroxyproline