Isolation of the transferrin receptor from human placenta

Abstract

SummaryThe transferrin receptor (TFR) has been detected in tissues eharacterised by a high degree of proliferation. We have developed a procedure for isolating TFR from human placental tissues by affinity chromatography on transferrinSepharose. Using gel filtration and electrophoresis in 7% PAAG, it has been shown that the molecular mass of the protein is 180 kDa. The protein has a subunit structure and is made up of two identical subunits, 90 kDa each. The constant for the protein binding to transferrin is equal to 5 x 10 .9 M. The yield of the protein isolated by the novel procedure exceeds 5-fold that obtained by previously described methods.

Interaction Kinetics of Tetramethylrhodamine Transferrin with Human Transferrin Receptor Studied by Fluorescence Correlation Spectroscopy

“…As is evident from Figure 2, the fraction of labeled Tf bound to hTfR shows a dependence on the hTfR concentration typical for binding of Tf to equal and independent sites on the hTfR associate. The dissociation constant, determined using TMR-Tf as the ligand, equals 7 ( 3 nM which is in good agreement with the previously reported value of 5 nM, determined with purified, CHAPS-solubilized receptor using a radioimmunoassay (11,21). This close similarity between our dissociation constant and the literature data implies that the binding sites in detergent free solution are mainly located on the surface of the associates and are equally accessible from the bulk solution.…”

“…For various cell extracts, values between 0.12 and 1.1 nM were reported (8)(9)(10). In a recent study with purified hTfR, a dissociation constant of 5 nM was determined (11).…”

Molecular mimicry of the receptor-binding domain of the SARS-CoV-2 spike protein: from the interaction of spike-specific antibodies with transferrin and lactoferrin to the antiviral effects of human recombinant lactoferrin

“…To obtain an affinity sorbent for TfR1 purification we used holo-Tf immobilized on Sepharose 6B activated by BrCN (about 5 mg holo-Tf per 1 mL of wet gel). TfR1 was purified from human placenta with small modifications of earlier protocols (Seligman and Allen 1987 ; Turkewitz et al 1988 ; Kanevsky et al 1997 )—see Supplementary data, section S1. Soluble form of TfR (sTfR) was obtained by limited proteolysis of TfR with trypsin and by ion-exchange chromatography—see Supplementary data, section S2.…”