Recombinant Expression and Chemical Amidation of Isotopically Labeled Native Melittin

Table S1. Melittin backbone chemical shifts (ppm). Deuterium isotope shift corrections were applied to all chemical shifts and pressure corrections were applied to the pressure denatured monomer chemical shifts. All shifts were measured on a 1.0-mM ²H,¹³C,¹⁵N-labeled melittin sample in 25-mM potassium phosphate buffer, pH 7.0, 50-mM NaCl, 3% D2O. The folded tetramer peaks were measured at atmospheric pressure, while the pressure denatured monomer resonances were measured at 2.25 kbar.

Table S2. Melittin experimental ¹⁵N-¹H isotropic J-couplings, (J+¹D_NH) anisotropic couplings and ¹D_NH residual dipolar couplings. All couplings and errors are reported in Hz. Isotropic J-couplings were not measured for G3 and A4. In these cases, an average J-coupling of -93.3 Hz was used with an uncertainty of 1.1 Hz.

Table S3. 2MLT atomic coordinates. The X-ray crystal structure was retrieved from the protein data bank (PDB). Then it was symmetry expanded into a tetramer.

Table S4. AlphaFold-Multimer structural model atomic coordinates.