Fig. 6: General strategy for stabilizing helix-hairpin peptides.
From: A dimeric proteomimetic prevents SARS-CoV-2 infection by dimerizing the spike protein
a, Sequence and secondary structure map of an antiparallel coiled-coil region of the N-terminal domain of the transcription factor STAT-4. b, The X-ray crystal structure of the N-terminal domain of STAT-4 (PDB 1BGF). The antiparallel coiled-coil region chosen for truncation is highlighted in blue. The residues at a and d positions are shown in ball-and-stick representation. The surface of the residues at g positions are colored by residue: Glu is red, Gln is green, hydrophobic residues Leu and Ile are gray. c, Circular dichroism thermal unfolding transitions monitored at 222 nm. Data were fit to a two-state unfolding model to obtain the melting temperature (TM). The TM represents mean values ± s.d. derived from three independent experiments. d, Sequences, helicity, thermal stability and oligomeric state of the BGF variants. The modified residues in the loop are highlighted in red and the modification at g sites are highlighted in bold. Leu1 to Trp1 is substituted to allow for absorbance measurement at 280 nm wavelength.
