4htj

Publication Abstract from PubMed

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 membrane-proximal 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 properly-folded 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.

Biophysical Characterization of the Membrane-proximal Ectodomain of the Receptor-type Protein-tyrosine Phosphatase Phogrin.,Noguera ME, Primo ME, Sosa LN, Risso VA, Poskus E, Ermacora MR Protein Pept Lett. 2012 Sep 25. PMID:23016632^[3]

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