Protein / Peptide Structural Characterization

The primary structure of proteins and peptides is determined through peptide sequencing or N-terminus sequencing. One commonly used method for sequence analysis is Edman degradation, which involves the chemical removal of N-terminal amino acids one by one. In-gel electrophoresis generates peptides that can then be separated and analyzed using HPLC. This process is vital for protein identification and product homology, both of which are critical for pharmacological development.

A protein’s function is intricately linked to its structure, interactions with other proteins, and its specific location within cells, tissues, and organs. Understanding protein structure, expression levels, and mapping its location and interactions provides valuable insights into its biological function.

Several structural characterization techniques are used for comprehensive protein analysis, including LC-MS/MS for peptide identification, Peptide Map Validation using UPLC-UV (MS), and advanced methods like X-ray crystallography, NMR spectroscopy, Cryo-EM, and near-UV CD. Among these, NMR spectroscopy stands out as being particularly advantageous when compared to X-ray or cryo-EM methods. NMR is less dependent on sample conditions and is highly sensitive to tiny variations in the chemical environment, making it ideal for studying protein structures both in vitro and in vivo. It enables the determination of protein structures in solution under near-physiological conditions, offering a deeper understanding of how proteins function within living systems.