A Simple Two-Step Approach for Introducing a Protected Diaminedithiol Chelator during Solid-Phase Assembly of Peptides
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- 作者：Jean Garié ; py ; Sandrine Ré ; my ; Xiuguo Zhang ; James R. Ballinger ; Eleonora Bolewska-Pedyczak ; Michael Rauth ; and Stuart K. Bisland
- 刊名：Bioconjugate Chemistry
- 出版年：2002
- 出版时间：May 2002
- 年：2002
- 卷：13
- 期：3
- 页码：679 - 684
- 全文大小：97K
- 年卷期：v.13,no.3(May 2002)
- ISSN：1520-4812
文摘
A simple synthetic strategy is described to incorporate a protected diaminedithiol (N2S2) chelator duringFmoc solid-phase synthesis of short peptides. The resulting constructs could be efficiently labeledwith 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 aprotected N2S2 chelator. This metal binding site was introduced into di- and tripeptides. Each peptideconstruct was composed of a C-terminal lysine residue and an N-terminal diaminopropionic moietymodified to create the chelator site. The 
BORDER=0 >-amino group at the C-terminal lysine was further derivatizedwith a nitroimidazole group to facilitate cellular retention. The resulting constructs were then cleavedfrom the resin support, purified, and labeled with [99mTc]pertechnetate. Six constructs were prepareddiffering 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 
C for 10 min.Purified 99mTc-labeled constructs were found to accumulate in Chinese hamster ovary (CHO) cells invitro as a function of charge and hydrophobicity.
BORDER=0 >-amino group at the C-terminal lysine was further derivatizedwith a nitroimidazole group to facilitate cellular retention. The resulting constructs were then cleavedfrom the resin support, purified, and labeled with [99mTc]pertechnetate. Six constructs were prepareddiffering 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 C for 10 min.Purified 99mTc-labeled constructs were found to accumulate in Chinese hamster ovary (CHO) cells invitro as a function of charge and hydrophobicity.