Demonstration of the specific binding of bovine transferrin to the human transferrin receptor in K562 cells: evidence for interspecies transferrin internalization

Journal Article · Tue Jul 01 04:00:00 EDT 1986 · J. Cell. Physiol.; (United States)

DOI:https://doi.org/10.1002/jcp.1041280102· OSTI ID:6942645

Tsavaler, L; Stein, B S; Sussman, H H

Specific binding of ferric bovine transferrin to the huyman transferrin receptor was investigated using K562 cells propagated in serum-free medium without transferrin supplemented with 10/sup -5/ elemental iron. Affinity chromatography of solubilized extracts of K562 cells surface-labeled with /sup 125/I was performed using bovine transferrin- and human transferrin-Sepharose 4B resins. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of resin eluates reveal that bovine transferrin specifically binds a M/sub r/ = 188,000 protein which dissociates into a M/sub r/ = 94,000 protein under reducing conditions, a finding identical to what is seen with human transferrin. The M/sub r/ = 94,000 reduced protein isolated by bovine transferrin resin shows an identical one-dimensional partial proteolytic digestion map with that of the human transferrin receptor. Unlabeled bovine transferrin was shown to specifically compete /sup 125/I-labeled human transferrin from the human transferrin receptor on the surface of K562 cells at 4/sup 0/C in a similar manner as unlabeled human transferrin; however, approximately a 2000-fold higher concentration of bovine ligand was required to achieve comparable competition (50% inhibition of binding). Indirect immunofluorescence cytolocalization of bovine transferrin in K562 cells grown in serum-free medium supplemented with ferric bovine transferrin reveal patterns similar to those seen for human transferrin. K652 cells grown in serum-free medium supplemented with either 300 ..mu..g/ml of ferric human or ferric bovine transferrin were found to demonstrate superimposable growth curve.

• Research Organization: Stanford Univ., CA
• OSTI ID: 6942645
• Journal Information: J. Cell. Physiol.; (United States), Journal Name: J. Cell. Physiol.; (United States) Vol. 128:1; ISSN JCLLA
• Country of Publication: United States
• Language: English

Related Subjects

550301* -- Cytology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
CATTLE
CELL CULTURES
CONFIGURATION INTERACTION
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
GLOBULINS
GLOBULINS-BETA
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MAN
MEMBRANE PROTEINS
METALLOPROTEINS
MOLECULAR WEIGHT
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PRIMATES
PROTEINS
RADIOISOTOPES
RADIORECEPTOR ASSAY
RECEPTORS
RUMINANTS
TRACER TECHNIQUES
TRANSFERRIN
VERTEBRATES