A high yield purification of the human transferrin receptor and properties of its major extracellular fragment.
Human transferrin receptor is a disulfide-linked homodimer of 90-kDa glycoprotein subunits, capable of binding two transferrins. We report a new high yield affinity purification protocol for transferrin receptor from placenta which produces 3-4 mg of highly purified protein. Trypsin cleaves the protein at arginine-121, producing a stable fragment that contains 95% of the extracytoplasmic sequence; similar fragments are produced by several other proteases. The tryptic fragment is a nondisulfide-linked dimer in solution and binds two transferrin molecules. The dimensions of both the dimer fragment and its complex with transferrin are estimated by gel filtration.
Turkewitz
A P
AP
Department of Biochemistry, Harvard University, Cambridge, Massachusetts 02138.
Amatruda
J F
JF
Borhani
D
D
Harrison
S C
SC
Schwartz
A L
AL
D000465:Algorithms; D000595:Amino Acid Sequence; D006801:Humans; D008722:Methods; D010446:Peptide Fragments / Q000032:analysis; D010449:Peptide Mapping; D010920:Placenta / Q000032:analysis; D011990:Receptors, Transferrin / Q000302:isolation & purification*; D014357:Trypsin / Q000378:metabolism
D010446:Peptide Fragments; D011990:Receptors, Transferrin; D014357:Trypsin