PREPARATION OF A POLYETHYLENE-GLYCOL - SUPEROXIDE-DISMUTASE ADDUCT, AND AN EXAMINATION OF ITS BLOOD CIRCULATING LIFE AND ANTI-INFLAMMATORY ACTIVITY

  • 1 January 1980
    • journal article
    • research article
    • Vol. 29  (1) , 113-127
Abstract
Methoxypolyethylene glycol (PEG) of 5000 daltons was attached covalently to 19 of the 20 available Lys residues of bovine erythrocyte superoxide dismutase. The adduct (PEG-superoxide dismutase) has 51% of the enzymatic activity of superoxide dismutase. PEG-superoxide dismutase exhibits a sharply enhanced serum circulating life during repetitive i.v. injections [to mice] compared to the native enzyme. While no evidence of an immune response to repetitive injections of PEG-superoxide dismutase is observed, the unmodified enzyme appears to produce slight sensitization in the form of quicker removal from the serum after 13 injections over 30 days. Antisera to superoxide dismutase and PEG-superoxide dismutase produce no detectable antibodies as determined by the Ouchterlony method. I.p. injected PEG-superoxide dismutase enters the bloodstream more readily than superoxide dismutase. PEG modification slightly improves the enzyme''s anti-inflammatory activity, which was observed in rats over 8 days.