title: A high-performance-liquid-chromatographic method for the assay of coproporphyrinogen oxidase activity in rat liver.
abstract: An h.p.l.c. method was developed for the assay of coproporphyrinogen oxidase activity in rat liver. The protoporphyrinogen IX formed is completely oxidized to protoporphyrin IX for separation and quantification by reversed-phase chromatography with mesoporphyrin as the internal standard. The Km of coproporphrinogen oxidase is 1.01 +/- 0.23 microM. The activities are 4.07 +/- 0.40 nmol of protoporphyrin IX/h per mg of mitochondrial protein and 224 +/- 19 nmol of protoporphyrin IX/h per g of liver tissue homogenate. The method is sensitive enough for measuring enzyme activity in small amounts of human tissue from needle biopsy.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003304:Coproporphyrinogen Oxidase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D011524:Protoporphyrins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D011524:Protoporphyrins; C011539:protoporphyrinogen; C028025:protoporphyrin IX; D010088:Oxidoreductases; D003304:Coproporphyrinogen Oxidase