The Synthesis And Properties Of Enkephalin Oligonucleotide Conjugates

Oligonucleotide is a kind of biological important molecular， so DNA or RNA sequencescan be targeting through specific recognition of base sequences and paired with the targetsequence specific binding to inhibit gene transcription and translation by oligonucleotide.Most of them can be used as drugs or a type of potential gene therapy. However， theirsystemic therapeutic use is hindered by their poor cellular uptake and inability to reach themucless. Desined improvement of certain propenties，such as cell-specific delivery，cellularuptake，efficiency and target specificity can be achieved by covalent association to peptides. Akind of opioid-enkephalin was chosen because of its important physiological functions inanimals. In many strategies of peptide-oligonucleotide conjugate synthesis，coniugationthrough triazoleformation is porpular because of biological activity， stability and selectivity.In this paper，reference Kumar’s way, a peptide is modified by an alkynyl group at theN-terminus and an oligonucleotide labeled by an azido group at the5′-end. The corresponding5′-azidohexyl oligonucleotide is used for ‘Click’ conjugation with enkephalin-alkyne ataqueous conditions to produce enkephalin-oligonucleotide conjugates conjugates in highpurity and yield.The product was purified by RP-HPLC and characterized by ESI-MS. Finally, theEnkephalin-oligonucleotide conjugates hydrolytic stability was studied，The result show thatthe triazole linkage is stable at slightly acidic to slightly alkaline; Interaction of enkephalin-oligonucleotide conjugates with pUC18DNA was studied by Agarose gel electropHoresis，The results show the interaction of enkephalin-oligonucleotide conjugates with pUC18DNAis stronger than that of enkephalin.