Synthesis of Oligonucleotide–Peptide Conjugates for Biomedical and Technological Applications

Abstract

Oligonucleotide-peptide conjugates have attracted considerable interest especially for biomedical uses. In the first part of this chapter, we describe protocols for the stepwise synthesis of oligonucleotides carrying peptide sequences at the 3'-end on a single support. The resulting oligonucleotide-peptide conjugates may be used as exogenous effectors for the specific control of gene expression. In the second part of this chapter, detailed postsynthetic conjugation protocols to introduce peptide sequences into oligonucleotide sequences are also presented.2

Oligonucleotide-Peptide Conjugates: Solid-Phase Synthesis under Acidic Conditions and Use in ELISA Assays

“…First, the peptide with acid-labile side chain protection was assembled using the following groups for the protection of the side chains of amino acids: triphenylmethyl (Trt) for histidine; tert -butyl ( t -Bu) for serine and threonine; 2,2,5,7,8-pentamethyl-chroman-6-sulfonyl (Pmc) for arginine, tert -butoxycarbonyl (Boc) for lysine and acetamidomethyl (Acm) for cysteine. Then 4- O -trityl-4-hydroxybutyric acid linker was added to the N -terminal position of the peptide support [ 10 , 13 ]. This linker generates a free hydroxyl after the removal of the trityl group, thus allowing assembly of the oligonucleotide sequence on a DNA synthesizer.…”

“…Since the concentration of OPC tested (25 pmol/well) was about 10-fold lower than the peptide concentration used in the previously reported ELISAs [ 10 , 21 ], next we tested 250 pmol/well of duplex OPC following the same experimental procedure. The reactivity of RA sera was now significantly higher, while BD control sera remained low ( Figure 8 ).…”

“…To date, several protocols for the chemical synthesis of OPCs have been described [ 8 , 9 , 10 , 11 , 12 ]. Conjugation of these large and functionalized molecules is a difficult task and often hindered by several side-reactions.…”

“…Post-synthetic conjugation protocols were successfully applied to synthesize the oligonucleotide-linear fibrin peptide conjugate but were not efficient for the synthesis of the longer oligonucleotide-chimeric peptide conjugates. A new protocol for the stepwise synthesis of oligonucleotide-linear fibrin peptide conjugates using an acidic treatment for the final deprotection step is described, as the presence of five arginines in the peptide sequence precludes the use of the base-labile protecting groups [ 8 , 9 , 10 , 11 , 12 ]. In addition, the formation of the disulfide bond between the two cysteine residues of CFFCP1 was assessed after removal of the oligonucleotide-peptide conjugate from the solid support.…”

Functionalization and Self-Assembly of DNA Bidimensional Arrays

“…This oligonucleotide was treated with tris(carboxyethyl)phosphine to remove the t -butylthio protecting group. The corresponding free thiol oligonucleotide was reacted with the corresponding maleimido derivatives as described [ 17 – 20 ] ( Scheme 2 ) to yield the desired conjugates ( 14 – 15 ). Fluorescein and peptide conjugates 14 and 15 were purified by gel electrophoresis ( supplementary information ).…”