Solid-phase synthesis and purification of a set of uniformly ¹³C, ¹⁵N labelled de novo designed membrane fusogenic peptides

The transmembrane segments of soluble N-ethylmaleimide-sensitive factor (SNARE) proteins or viral envelope proteins drive membrane fusion, which suggests that simple synthetic biology constructs for fusion exist and can be evaluated. We describe the high-yield synthesis of a set of de novo designed fusogenic peptides for use in functional investigations, which are highly enriched in ¹³C and ¹⁵N using three equivalents of labelled amino acids and optimized reaction conditions minimizing aggregation. The biomimetic peptides have a high purity >90% and show reproducible and fusogenic activity that correlates well with the intended functional design characteristics, from strongly fusogenie to almost non-fusogenic.