Fatty acyl coupled catalase

Bovine liver catalase (hydrogen-peroxide:hydrogen peroxide oxidoreductase, EC 1.11.1.6) was derivatized by 9″(10″)-[4′-{2-(4,6-dichloro-1,3,5-triazinyl)oxy}butoxy]stearic acid and the fatty acyl-coated enzyme was separated from native catalase and excess reagent by hydroxyapatite chromatography. The derivatization of catalase resulted in coupling the long-chain fatty acyl residues to lysine, histidine and arginine, while other amino acids remained essentially unaffected. The fatty acyl-coated enzyme was water soluble at pH > 7.0 but became octanol and ether soluble at pH < 6.5. The derivatized enzyme retained 50-80% of the catalatic- and peroxidative-specific activities. The free carboxyl function of the coupled long-chain fattyl acyl residues could serve as substrate for ATP-dependent CoA-thioesterification catalyzed by the rat liver microsomal long-chain fatty acyl-CoA synthase.