Interrogation of solution conformation of complex macrocyclic peptides utilizing a combined SEC-HDX-MS, circular dichroism, and NMR workflow

Recent technological and synthetic advances have led to a resurgence in the exploration of peptides as potential therapeutics. Understanding peptide conformation in both free and protein-bound states remains one of the most critical areas for successful development of peptide drugs. In this study it was demonstrated that the combination of Size-Exclusion Chromatography with Hydrogen-Deuterium Exchange Mass Spectrometry (SEC-HDX-MS) and Circular Dichroism Spectroscopy (CD) can be used to guide the selection of peptides for further NMR analysis. Moreover, the insights from this workflow guide the choice of the best biologically relevant conditions for NMR conformational studies of peptide ligands in a free state in solution. Combined information about solution conformation character and stability across temperatures and co-solvent compositions greatly expedites selection of optimal conditions for NMR analysis. In total, the combination of SEC-HDX-MS, CD, and NMR into a single complementary workflow greatly accelerates conformational analysis of peptides in the drug discovery lead optimization process.