Laser light-scattering evidence for an altered association of beta B1-crystallin deamidated in the connecting peptide.
Protein Sci
; 13(3): 678-86, 2004 Mar.
Article
en En
| MEDLINE
| ID: mdl-14978307
ABSTRACT
Deamidation is a prevalent modification of crystallin proteins in the vertebrate lens. The effect of specific sites of deamidation on crystallin stability in vivo is not known. Using mass spectrometry, a previously unreported deamidation in beta B1-crystallin was identified at Gln146. Another deamidation was investigated at Asn157. It was determined that whole soluble beta B1 contained 13%-17% deamidation at Gln146 and Asn157. Static and quasi-elastic laser light scattering, circular dichroism, and heat aggregation studies were used to explore the structure and associative properties of recombinantly expressed wild-type (wt) beta B1 and the deamidated beta B1 mutants, Q146E and N157D. Dimer formation occurred for wt beta B1, Q146E, and N157D in a concentration-dependent manner, but only Q146E showed formation of higher ordered oligomers at the concentrations studied. Deamidation at Gln146, but not Asn157, led to an increased tendency of beta B1 to aggregate upon heating. We conclude that deamidation creates unique effects depending upon where the deamidation is introduced in the crystallin structure.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Cristalinas
/
Subunidades de Proteína
/
Amidas
Tipo de estudio:
Risk_factors_studies
Límite:
Humans
/
Middle aged
Idioma:
En
Revista:
Protein Sci
Asunto de la revista:
BIOQUIMICA
Año:
2004
Tipo del documento:
Article
País de afiliación:
Estados Unidos