Expression and physicochemical characterization of an extracellular segment of the receptor protein tyrosine phosphatase IA-2.
Biochim Biophys Acta
; 1764(2): 174-81, 2006 Feb.
Article
em En
| MEDLINE
| ID: mdl-16413232
The receptor protein tyrosine phosphatase superfamily (RPTP) includes proteins with a single transmembrane, one or more intracellular phosphatase, and a variety of extracellular domains. The 106-kDa insulinoma-associated protein (IA-2, ICA512) receptor is unique among RPTP members because: (a) it has a single, phosphatase-like intracellular domain identified as one of the most prominent self antigens in autoimmune diabetes; (b) its extracellular region bears no sequence similarity to known domains; (c) it is present in the membrane of secretory granules in neurons and pancreatic beta-cells where it suffers a complex processing; and (d) it has very poorly understood biological properties. In this work, we describe the expression, purification, and physicochemical characterization of residues 449-576 of IA-2 (IA-2ec(449-576)). Judging from CD, fluorescence, hydrodynamic, and thermal unfolding analyses, this fragment forms an autonomously folding unit with tight packing and well-defined secondary and tertiary structure. CD analysis suggests that about 25% of IA-2ec(449-576) residues are alpha-helical, whereas about the same amount are in beta-sheet structure. The availability of soluble and folded IA-2ec(449-576) is a step forward toward the characterization of a part of IA-2 at atomic detail, which may provide new insight in the biology of diabetes, the neurotransmission process, and the dynamic of secretory granules.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Autoantígenos
/
Proteínas Recombinantes
/
Proteínas Tirosina Fosfatases
/
Proteínas de Membrana
Limite:
Humans
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Holanda