Modulation of integrin activation by an entropic spring in the {beta}-knee.
J Biol Chem
; 285(43): 32954-32966, 2010 Oct 22.
Article
en En
| MEDLINE
| ID: mdl-20670939
ABSTRACT
We show that the length of a loop in the ß-knee, between the first and second cysteines (C1-C2) in integrin EGF-like (I-EGF) domain 2, modulates integrin activation. Three independent sets of mutants, including swaps among different integrin ß-subunits, show that C1-C2 loop lengths of 12 and longer favor the low affinity state and masking of ligand-induced binding site (LIBS) epitopes. Shortening length from 12 to 4 residues progressively increases ligand binding and LIBS epitope exposure. Compared with length, the loop sequence had a smaller effect, which was ascribable to stabilizing loop conformation, and not interactions with the α-subunit. The data together with structural calculations support the concept that the C1-C2 loop is an entropic spring and an emerging theme that disordered regions can regulate allostery. Diversity in the length of this loop may have evolved among integrin ß-subunits to adjust the equilibrium between the bent and extended conformations at different set points.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Modelos Moleculares
/
Cadenas beta de Integrinas
/
Factor de Crecimiento Epidérmico
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Biol Chem
Año:
2010
Tipo del documento:
Article