title: The isolation of an o-diphenal oxidase from third-instar larvae of the blowfly Calliphora erythrocephala.
abstract: 1. The isolation of an o-diphenol oxidase from an acetone-dried powder of late-third-instar larvae of Calliphora erythrocephala was investigated. An insoluble and micro-crystalline fraction containing the enzyme activity was obtained after fractionating extracts of the acetone-dried powder with (NH4)2SO4 and acetone. 2. This fraction can be solubilized in 0.1% sodium dodecyl sulphate without loss of activity. 3. Polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate shows that the o-diphenol oxidase is a minor component of the extracts from the acetone-dried powder. 4. The o-diphenol oxidase was purified by zonal centrifugation on a sucrose density gradient in the presence of sodium dodecyl sulphate. 5. The amino acid composition of the purified enzyme resembles that of some other o-diphenol oxidases. 6. The subunit composition of the o-diphenol oxidase is discussed.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004156:Catechol Oxidase / Q000032:analysis / Q000302:isolation & purification*; D004175:Diptera / Q000201:enzymology*; D007814:Larva / Q000201:enzymology
chemical_list: D000596:Amino Acids; D004156:Catechol Oxidase