Intradomain confinement of disulfides in the folding of two consecutive modules of the LDL receptor

The LDL receptor internalizes circulating LDL and VLDL particles for degradation. Its extracellular binding domain contains ten (seven LA and three EGF) cysteine-rich modules, each bearing three disulfide bonds. Despite the enormous number of disulfide combinations possible, LDLR oxidative folding l...

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Detalles Bibliográficos
Autores: Martínez-Oliván, Juan, Fraga, Hugo, Arias-Moreno, Xabier, Ventura, Salvador|||0000-0002-9652-6351, Sancho Sanz, Javier|||0000-0002-2879-9200
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:225180
Acceso en línea:https://ddd.uab.cat/record/225180
https://dx.doi.org/urn:doi:10.1371/journal.pone.0132141
Access Level:acceso abierto
Palabra clave:Binding sites
Calcium
Cysteine
Disulfides
Humans
Models, Molecular
Oxidation-reduction
Protein folding
Receptors, LDL
Recombinant proteins
Descripción
Sumario:The LDL receptor internalizes circulating LDL and VLDL particles for degradation. Its extracellular binding domain contains ten (seven LA and three EGF) cysteine-rich modules, each bearing three disulfide bonds. Despite the enormous number of disulfide combinations possible, LDLR oxidative folding leads to a single native species with 30 unique intradomain disulfides. Previous folding studies of the LDLR have shown that non native disulfides are initially formed that lead to compact species. Accordingly, the folding of the LDLR has been described as a "coordinated nonvectorial" reaction, and it has been proposed that early compaction funnels the reaction toward the native structure. Here we analyze the oxidative folding of LA4 and LA5, the modules critical for ApoE binding, isolated and in the LA45 tandem. Compared to LA5, LA4 folding is slow and inefficient, resembling that of LA5 disease-linked mutants. Without Ca<sup.