Solid-Supported Synthesis of 5′-mRNA CAP-4 from Trypanosomatids

Abstract

The unique structure of 5′ mRNA cap from Trypanosomatids is the most modified cap found in nature. Here we present the synthesis of cap-4 (m ⁷ Gpppm ₃ ^6,6,2′ Apm ^2′ Apm ^2′ Cpm ₂ ^3,2′ Up) on a disulfide-tethered solid support. This approach allows obtaining cap-4 more efficiently then previously described. Moreover such modified resin could be a useful tool for affinity purification of Leishmania proteins interacting with cap-4. For the final step of synthesis, namely coupling of phosphorylated tetranucleotide with activated 7-methylguanosine 5′-diphosphate two systems were compared. Surprisingly, the coupling in water with Mn ²⁺ as a catalyst, gave better results than usually more effective coupling in DMF with ZnCl ₂ .

Keywords:

• 5′
• mRNA Cap-4
• disulfide linker
• Leishmania
• oligonucleotide synthesis
• solid support

This work was supported by grant from Polish Ministry of Science and Higher Education (No. 2 P04A 006 28) and grant from HHMI (No. 55005604).