Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/71841
Type: Artigo de periódico
Title: Solution conformation and heparin-induced dimerization of the full-length extracellular domain of the human amyloid precursor protein
Author: Gralle, M
Oliveira, CLP
Guerreiro, LH
McKinstry, WJ
Galatis, D
Masters, CL
Cappai, R
Parker, MW
Ramos, CHI
Torriani, I
Ferreira, ST
Abstract: Proteolytic cleavage of the amyloid precursor protein (APP) by beta and gamma-secretases gives rise to the beta-amyloid peptide, considered to be a causal factor in Alzheimer's disease. Conversely, the soluble extracellular domain of APP (sAPP alpha), released upon its cleavage by alpha-secretase, plays a number of important physiological functions. Several APP fragments have been structurally characterized at atomic resolution, but the structures of intact APP and of full-length sAPP alpha have not been determined. Here, ab initio reconstruction of molecular models from high-resolution solution X-ray scattering (SAXS) data for the two main isoforms of sAPP alpha (sAPP alpha(695) and sAPP alpha(770)) provided models of sufficiently high resolution to identify distinct structural domains of APP. The fragments for which structures are known at atomic resolution were fitted within the solution models of full-length sAPPa, allowing localization of important functional sites (i.e. glycosylation, protease inhibitory and heparin-binding sites). Furthermore, combined results from SAXS, analytical ultracentrifugation (AUC) and size-exclusion chromatography (SEC) analysis indicate that both sAPP alpha isoforms are monomeric in solution. On the other hand, SEC, bis-ANS fluorescence, AUC and SAXS measurements showed that sAPPa forms a 2:1 complex with heparin. A conformational model for the sAPP alpha:heparin complex was also derived from the SAXS data. Possible implications of such complex formation for the physiological dimerization of APP and biological signaling are discussed in terms of the structural models proposed. (c) 2005 Elsevier Ltd. All rights reserved.
Subject: analytical ultracentrifugation
modeling
signal transduction
small-angle X-ray scattering
structural domains
Country: Inglaterra
Editor: Academic Press Ltd Elsevier Science Ltd
Rights: fechado
Identifier DOI: 10.1016/j.jmb.2005.12.053
Date Issue: 2006
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

Files in This Item:
File Description SizeFormat 
WOS000236120200013.pdf738.67 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.