Isolation of a transferrin receptor structure from sodium deoxycholate-solubilized human placental syncytiotrophoblast plasma membrane.

A human placental transferrin receptor structure has been isolated as a complex with doubly-radiolabelled (125I, 59Fe) human transferrin following gel filtration and affinity chromatography of sodium deoxycholate-solubilized protein from isolated syncytiotrophoblast microvillous plasma membrane vesicle preparations. The molecular weight of this complex has been determined to be 150 000 by Sepharose 6B gel filtration. The molecular weights of the constituent components of the complex have been determined by sodium dodecyl sulphate/polyacrylamide disc gel electrophoresis to be 80 000 (representing transferrin) and 65 000 (representing the deoxycholate-solubilized receptor structure). The binding activity of this placental transferrin receptor structure is maintained in sodium deoxycholate and is not requisite on being an integral component of the cell membrane.