Download MendeleyX-ray Characterization of Conformational Changes of Human Apo- and Holo-Transferrin.
Campos-Escamilla, C., Siliqi, D., Gonzalez-Ramirez, L.A., Lopez-Sanchez, C., Gavira, J.A., Moreno, A.(2021) Int J Mol Sci 22
- PubMed: 34948188
- DOI: https://doi.org/10.3390/ijms222413392
- Primary Citation of Related Structures:
7Q1L - PubMed Abstract:
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 Å 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.
Organizational Affiliation:
Instituto de Química, Universidad Nacional Autónoma de Mexico, Av. Universidad 3000, Ciudad Universitaria, Ciudad de Mexico 04510, Mexico.
