Purification and characterization of the intestinal promoter of iron(3+)-transferrin formation.
The nonceruloplasmin enzyme located in the intestinal mucosa which promotes the incorporation of iron into transferrin has been resolved into a small, heat-stable component and a heat-labile protein component. The small, heat-stable component was purified from the high-speed supernatant of intestinal mucosal homogenates by ion-exchange chromatography and gel filtration and identified as xanthine. The heat labile protein component was purified from the high-speed supernatant of intestinal mucosal homogenates by heat treatment, gel filtration, and ion-exchange chromatography. The physical, spectral, and kinetic properties of the heat-labile protein component strongly suggest that it is xanthine oxidase. By promotion of the oxidation and incorporation of iron into transferrin, intestinal xanthine oxidase could perform a similar function in iron absorption as ceruloplasmin serves in the mobilization of iron from liver stores.
D000493:Allopurinol / Q000494:pharmacology; D000818:Animals; D004386:Duodenum / Q000201:enzymology*; D007413:Intestinal Mucosa / Q000201:enzymology*; D007501:Iron / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry; D013481:Superoxides / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000302:isolation & purification / Q000378:metabolism*
D014168:Transferrin; D013481:Superoxides; D000493:Allopurinol; D007501:Iron; D014969:Xanthine Oxidase