Dimerization interface of osteoprotegerin revealed by hydrogen-deuterium exchange mass spectrometry.
J Biol Chem
; 293(45): 17523-17535, 2018 11 09.
Article
em En
| MEDLINE
| ID: mdl-30254073
ABSTRACT
Previous structural studies of osteoprotegerin (OPG), a crucial negative regulator of bone remodeling and osteoclastogenesis, were mostly limited to the N-terminal ligand-binding domains. It is now known that the three C-terminal domains of OPG also play essential roles in its function by mediating OPG dimerization, OPG-heparan sulfate (HS) interactions, and formation of the OPG-HS-receptor activator of nuclear factor κB ligand (RANKL) ternary complex. Employing hydrogen-deuterium exchange MS methods, here we investigated the structure of full-length OPG in complex with HS or RANKL in solution. Our data revealed two noteworthy aspects of the OPG structure. First, we found that the interconnection between the N- and C-terminal domains is much more rigid than previously thought, possibly because of hydrophobic interactions between the fourth cysteine-rich domain and the first death domain. Second, we observed that two hydrophobic clusters located in two separate C-terminal domains directly contribute to OPG dimerization, likely by forming a hydrophobic dimerization interface. Aided by site-directed mutagenesis, we further demonstrated that an intact dimerization interface is essential for the biological activity of OPG. Our study represents an important step toward deciphering the structure-function relationship of the full-length OPG protein.
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Base de dados:
MEDLINE
Assunto principal:
Espectrometria de Massas
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Medição da Troca de Deutério
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Osteoprotegerina
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Multimerização Proteica
Limite:
Animals
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article