Specific Disulfide Bond Formation Directed by Peptide Nucleic Acids

Abstract

In this study, we successfully demonstrated a strategy for specific disulfide bond formation by hybridization of two complementary peptide nucleic acid strands. Peptides were linked to the pair of complementary peptide nucleic acids by native chemical ligation, respectively, and base pairing drove the two peptides into close proximity for interchain disulfide bond formation. Since peptide nucleic acids directed system is easier to manipulate than deoxyribonucleic acid system, this system will be more useful and have a broader application scope in the construction of complex biomolecular structures.

Two‐Helix Supramolecular Proteomimetic Binders Assembled via PNA‐Assisted Disulfide Crosslinking

“…Expectedly, when mixed in equimolar ratio, B and R peptides (devoid of PNA) yielded mixture of all possible products (Figure 2a); in contrast, the nucleic acid containing hybrids formed almost exclusively the desired heterodimer as verified by LC–MS analysis (Figure 2b), consistent with hybridization‐driven templated reaction [51–54] . Mixing the substrates at 50 μ m and incubation for 24 h resulted in a low apparent conversion (<25 %), with mostly unreacted starting materials therefore additional conditions and additives were screened (Figure 2c).…”

“…[50] Expectedly, when mixed in equimolar ratio, B and R peptides (devoid of PNA) yielded mixture of all possible products (Figure 2a); in contrast, the nucleic acid containing hybrids formed almost exclusively the desired heterodimer as verified by LC-MS analysis (Figure 2b), consistent with hybridization-driven templated reaction. [51][52][53][54] Mixing the substrates at 50 μm and incubation for 24 h resulted in a low apparent conversion (< 25 %), with mostly unreacted starting materials therefore additional conditions and additives were screened (Figure 2c). We have previously shown that the use of a similar 4-mer PNA tag allows for efficient templated chemistry (native chemical ligation) using substrates at 10 μm, [9] nonetheless due to the slower kinetics of the air/DMSO disulfide formation we achieved higher product formation (> 80 %, Figure 2d) chiefly by increasing the substrates concentration to 100 μm, while a slight elevation of temperature to 37 °C allowed for more reproducible results as well as desirable faster initial period.…”