Dissimilarity in the Contributions of the N-Terminal Domain Hydrophobic Core to the Structural Stability of Lens ß/γ-Crystallins.
Biochemistry
; 58(20): 2499-2508, 2019 05 21.
Article
en En
| MEDLINE
| ID: mdl-31037943
ABSTRACT
Vertebrate lens ß/γ-crystallins share a conserved tertiary structure consisting of four Greek-key motifs divided into two globular domains. Numerous inherited mutations in ß/γ-crystallins have been linked to cataractogenesis. In this research, the folding mechanism underlying cataracts caused by the I21N mutation in ßB2 was investigated by comparing the effect of mutagenesis on the structural features and stability of four ß/γ-crystallins, ßB1, ßB2, γC, and γD. Our results showed that the four ß/γ-crystallins differ greatly in solubility and stability against various stresses. The I21N mutation greatly impaired ßB2 solubility and native structure as well as its stability against denaturation induced by guanidine hydrochloride, heat treatment, and ultraviolet irradiation. However, the deleterious effects were much weaker for mutations at the corresponding sites in ßB1, γC, and γD. Molecular dynamics simulations indicated that the introduction of a nonnative hydrogen bond contributed to twisting Greek-key motif I outward, which might direct the misfolding of the I21N mutant of ßB2. Meanwhile, partial hydration of the hydrophobic interior of the domain induced by the mutation destabilized ßB1, γC, and γD. Our findings highlight the importance of nonnative hydrogen bond formation and hydrophobic core hydration in crystallin misfolding caused by inherited mutations.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Beta-Cristalinas
/
Gamma-Cristalinas
Límite:
Humans
Idioma:
En
Revista:
Biochemistry
Año:
2019
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA