Investigating the effects of mutations on protein aggregation in the cell.
J Biol Chem
; 280(11): 10607-13, 2005 Mar 18.
Article
em En
| MEDLINE
| ID: mdl-15611128
ABSTRACT
The conversion of peptides and proteins into highly ordered and intractable aggregates is associated with a range of debilitating human diseases and represents a widespread problem in biotechnology. Protein engineering studies carried out in vitro have shown that mutations promote aggregation when they either destabilize the native state of a globular protein or accelerate the conversion of unfolded or partially folded conformations into oligomeric structures. We have extended such studies to investigate protein aggregation in vivo where a number of additional factors able to modify dramatically the aggregation behavior of proteins are present. We have expressed, in Escherichia coli cells, an E. coli protein domain, HypF-N. The results for a range of mutational variants indicate that although mutants with a conformational stability similar to that of the wild-type protein are soluble in the E. coli cytosol, variants with single point mutations predicted to destabilize the protein invariably aggregate after expression. We show, however, that aggregation of destabilized variants can be prevented by incorporating multiple mutations designed to reduce the intrinsic propensity of the polypeptide chain to aggregate; in the cases discussed here, this is achieved by an increase in the net charge of the protein. These results suggest that the principles being established to rationalize aggregation behavior in vitro have general validity for situations in vivo where aggregation has both biotechnological and medical relevance.
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Base de dados:
MEDLINE
Assunto principal:
Tiazóis
/
Mutação
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Itália