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Publication Abstract from PubMed

Human serum transferrin (Tf) is a bilobed glycoprotein whose function is to transport iron through receptor-mediated endocytosis. The mechanism for iron release is pH-dependent and involves conformational changes in the protein, thus making it an attractive system for possible biomedical applications. In this contribution, two powerful X-ray techniques, namely Macromolecular X-ray Crystallography (MX) and Small Angle X-ray Scattering (SAXS), were used to study the conformational changes of iron-free (apo) and iron-loaded (holo) transferrin in crystal and solution states, respectively, at three different pH values of physiological relevance. A crystallographic model of glycosylated apo-Tf was obtained at 3.0 A resolution, which did not resolve further despite many efforts to improve crystal quality. In the solution, apo-Tf remained mostly globular in all the pH conditions tested; however, the co-existence of closed, partially open, and open conformations was observed for holo-Tf, which showed a more elongated and flexible shape overall.

X-ray Characterization of Conformational Changes of Human Apo- and Holo-Transferrin.,Campos-Escamilla C, Siliqi D, Gonzalez-Ramirez LA, Lopez-Sanchez C, Gavira JA, Moreno A Int J Mol Sci. 2021 Dec 13;22(24). pii: ijms222413392. doi:, 10.3390/ijms222413392. PMID:34948188^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.