The concave face of decorin mediates reversible dimerization and collagen binding.
J Biol Chem
; 288(49): 35526-33, 2013 Dec 06.
Article
em En
| MEDLINE
| ID: mdl-24169694
ABSTRACT
Decorin, the prototypical small leucine-rich proteoglycan, binds to collagen and thereby regulates collagen assembly into fibrils. The crystal structure of the decorin core protein revealed a tight dimer formed by the association of two monomers via their concave faces (Scott, P. G., McEwan, P. A., Dodd, C. M., Bergmann, E. M., Bishop, P. N., and Bella, J. (2004) Proc. Natl. Acad. Sci. U.S.A. 101, 15633-15638). Whether decorin binds collagen as a dimer has been controversial. Using analytical ultracentrifugation, we determined a dissociation constant of 1.37 ± 0.30 µm for the mouse decorin dimer. Dimerization could be abolished by engineering glycosylation sites into the dimer interface; other interface mutants remained dimeric. The monomeric mutants were as stable as wild-type decorin in thermal unfolding experiments. Mutations on the concave face of decorin abolished collagen binding regardless of whether the mutant proteins retained the ability to dimerize or not. We conclude that the concave face of decorin mediates collagen binding and that the dimer therefore must dissociate to bind collagen.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Colágeno
/
Decorina
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article