title: Carotene-cleavage activity in chick intestinal mucosa cytosol: association with a high-molecular-weight lipid-protein aggregate fraction and partial characterization of the activity.
abstract: A fluorescent high-molecular weight lipid-protein aggregate was isolated from the cytosol of chick intestinal mucosa or liver by gel filtration on columns of Sepharose 4B or 6B. This aggregate exhibited carotene-cleavage activity. On incubation of this aggregate, dissociation occurred and low-molecular weight fractions containing Cu and Zn and exhibiting carotene-cleavage activity were found. This fraction appeared on sodium dodecyl sulphate polyacrylamide electrophoresis to have a molecular weight of 7000-11000 and resembled the previously described Cu chelatins in amino acid composition. Carotene cleavage may be effected by a copper-zinc metalloprotein of low-molecular weight, associated in intestinal cytosol with a lipid-protein aggregate.
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000378:metabolism*; D002645:Chickens; D002850:Chromatography, Gel; D003300:Copper / Q000032:analysis; D003600:Cytosol / Q000201:enzymology; D007413:Intestinal Mucosa / Q000201:enzymology*; D008055:Lipids / Q000302:isolation & purification*; D046911:Macromolecular Substances; D008297:Male; D008970:Molecular Weight; D010105:Oxygenases / Q000302:isolation & purification*; D011506:Proteins / Q000302:isolation & purification*; D015032:Zinc / Q000032:analysis; D050559:beta-Carotene 15,15'-Monooxygenase
chemical_list: D008055:Lipids; D046911:Macromolecular Substances; D011506:Proteins; D002338:Carotenoids; D003300:Copper; D010105:Oxygenases; D050559:beta-Carotene 15,15'-Monooxygenase; D015032:Zinc