Thimet oligopeptidase and the stability of MHC class I epitopes in macrophage cytosol.
Biochem Biophys Res Commun
; 255(3): 596-601, 1999 Feb 24.
Article
em En
| MEDLINE
| ID: mdl-10049756
ABSTRACT
In this study we investigated the fate of a class of proteasome-generated oligopeptides, exposing them to the crude cytosol of macrophages or to the purified recombinant thimet oligopeptidase. Among the proteasome products of known sequences are MHC class I epitopes, 13 of which were randomly chosen to be used as putative substrates. Surprisingly, our results clearly showed that the majority of the peptides were poorly or not degraded, either by the purified enzyme or by the crude macrophage cytosol. The peptides, which were resistant to hydrolysis, displayed high affinity for the thimet oligopeptidase as competitive inhibitors. Regardless of the fact that our data do not allow prediction of whether or not a specific peptide would be degraded, it seems very likely that the structural features, which rule out the stability of the MHC class I peptides in the cytosol, may have implications in an optimized repertoire selection for antigen presentation.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oligopeptídeos
/
Metaloendopeptidases
/
Antígenos de Histocompatibilidade Classe I
/
Macrófagos
Limite:
Animals
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
1999
Tipo de documento:
Article