Synthesis of cyclic peptide hybrids with amino acid and nucleobase side-chains

Novel cyclopeptides for the design of MMP directed delivery devices: a novel smart delivery paradigm

PURPOSE

Matrix metalloproteinases (MMP) are a family of proteolytic enzymes, the expression of which in a key step of tumor progression has been better defined recently. The studies highlighted the ongoing need for very specific inhibitors, substrates or release devices designed to be selective for one or at least very few MMPs.

METHODS

This report deals with the design, synthesis and in vitro evaluation of linear and especially novel cyclic peptidic moieties, embodying MMP cleavable sequences designed to answer these questions. FRET (fluorescence resonance energy transfer) labelling via chromophore-modified amino-acids was used to give access to enzyme kinetics.

RESULTS

Evaluation of these peptides showed that cyclisation gives rise to high specificity for certain MMP, suggesting that this approach could provide very specific MMP substrate. Moreover, cyclic structures present a very good plasma stability.

CONCLUSIONS

These original derivatives could allow the design of MMP-controlled delivery devices, the specificity of which will be retained in complex biological media and in vivo.

Solid-phase synthesis and thermal denaturation study of cyclic PNAs targeting the HIV-1 TAR RNA loop

Cyclic PNAs targeting the HIV-1 TAR RNA loop have been synthesized following a convenient solid-phase strategy which allows on-resin cyclisation. UV-monitored thermal denaturation studies demonstrate that these cyclic PNAs are able to strongly interact with their TAR RNA target, very likely through the formation of a six-base pair stable complex, involving the TAR RNA loop.

Solid-phase synthesis of cyclic PNA and PNA-DNA chimeras

[structure: see text] A new and versatile on-line automated solid-phase approach to obtain cyclic PNA (I and III) and cyclic PNA-DNA chimeras (II) in highly pure form has been developed. Starting from a Tentagel matrix functionalized with a 3-chloro-4-hydroxyphenylacetic linker, the synthesis of representative, new cyclic molecules by standard peptide and phosphoramidite-based chemistry has been achieved.