IDEHU   05542
INSTITUTO DE ESTUDIOS DE LA INMUNIDAD HUMORAL PROF. RICARDO A. MARGNI
Unidad Ejecutora - UE
artículos
Título:
Biophysical Characterization of the Membrane-proximal Ectodomain of the Receptor-type Protein-tyrosine Phosphatase Phogrin.
Autor/es:
NOGUERA ME; PRIMO ME; SOSA LN; RISSO VA; POSKUS E; ERMÁCORA MR.
Revista:
PROTEIN AND PEPTIDE LETTERS
Editorial:
BENTHAM SCIENCE PUBL LTD
Referencias:
Lugar: Oak Park; Año: 2012 vol. 20 p. 1 - 9
ISSN:
0929-8665
Resumen:
The receptor-type protein-tyrosine phosphatase (RPTP) phogrin is localized at the membrane of secretory granules of pancreatic islet  beta cells and, similarly to the closely related ICA512, plays a role in the regulation of insulin secretion, in ensuring proper granulogenesis and stability, and in the regulation of beta cell growth. The mature membraneproximal ectodomain of phogrin (MPE phogrin) was produced as a recombinant protein and characterized. CD, fluorescence, controlled proteolysis, size-exclusion chromatography, and multi-angle ligth scattering showed that it is a properlyfolded monomeric domain. Equilibrium experiments, in the presence of guanidinium chloride and thermal unfolding, suggest a two-state mechanism with a deltaG of 2.3-3.3 kcal/mol, respectively. The study establishes common features and differences of MPE phogrin and the homologous ectodomain of ICA512. A homology model of phogrin was built based in the x-ray structure of MPE ICA512. The model is a starting point for modeling the entire receptor and for testing the quaternary structure and interactions of this protein in vivo. A description of the membrane insertion mode and putative interacting surfaces of this large protein is fundamental for the understanding of its biological function.