Recombinant Expression and Chemical Amidation of Isotopically Labeled Native Melittin

• Published in: Journal of the American Chemical Society Vol. 145; no. 7; pp. 3850 - 3854
• Main Authors: Gelenter, Martin D., Bax, Ad
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 22-02-2023
• Subjects: Communication
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.2c12631

Post-translational modifications are ubiquitous in the eukaryotic proteome. However, these modifications are rarely incorporated in NMR studies of eukaryotic proteins, which are typically produced through recombinant expression in E. coli. Melittin is the primary peptide in honey bee venom. Its native C-terminal amide significantly affects its equilibrium structure and dynamics in solution and is thus a prerequisite for studying its native structure and function. Here, we present a method for producing triply isotopically labeled (2H, 13C, and 15N) native melittin through recombinant expression followed by chemical amidation. We then show that structural models produced with AlphaFold-Multimer are in even better agreement with experimental residual dipolar couplings than the 2.0 Å resolution X-ray crystal structure for residues G3–K23.