A simple two-step approach for introducing a protected diaminedithiol chelator during solid-phase assembly of peptides.
Bioconjug Chem
; 13(3): 679-84, 2002.
Article
en En
| MEDLINE
| ID: mdl-12009962
ABSTRACT
A simple synthetic strategy is described to incorporate a protected diaminedithiol (N(2)S(2)) chelator during Fmoc solid-phase synthesis of short peptides. The resulting constructs could be efficiently labeled with technetium-99m (99mTc). The chelator was assembled at the N-terminus of peptides in a two-step procedure where the deprotected terminal amino group was first reacted with di-Fmoc-diaminopropionic acid (Fmoc-DAP-[Fmoc]-OH). The two protected amino groups were then simultaneously deprotected and subsequently reacted with S-benzoylthiolglycolic acid (TGA) to generate a protected N(2)S(2) chelator. This metal binding site was introduced into di- and tripeptides. Each peptide construct was composed of a C-terminal lysine residue and an N-terminal diaminopropionic moiety modified to create the chelator site. The epsilon-amino group at the C-terminal lysine was further derivatized with a nitroimidazole group to facilitate cellular retention. The resulting constructs were then cleaved from the resin support, purified, and labeled with [99mTc]pertechnetate. Six constructs were prepared differing by a single amino acid inserted between the diaminopropionic acid and lysine residues. Optimal labeling yields of >70% were achieved around neutral pH and heating at 75 degrees C for 10 min. Purified 99mTc-labeled constructs were found to accumulate in Chinese hamster ovary (CHO) cells in vitro as a function of charge and hydrophobicity.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Péptidos
/
Tolueno
/
Compuestos de Organotecnecio
/
Quelantes
/
Diaminas
Límite:
Animals
Idioma:
En
Revista:
Bioconjug Chem
Asunto de la revista:
BIOQUIMICA
Año:
2002
Tipo del documento:
Article