Protein Sequencing: Protein contains 20 different types of amino acids connected by a peptide bond. Each protein has unique amino acid sequence which dictates the folding, 3-D conformation and functional outcome. Understanding the amino acid sequence and over-all bonding pattern help us to characterize the protein.  

The sequencing of a long protein has multiple stages: A protein needs to go through following stages for elucidation of its sequence as well as bonding pattern. These stages are schematically given in Figure 38.1. Over-all, the complex protein first needs to break into the subunits, and sequential release of amino acids from N-terminus of each fragment following edman-degradation method. At the end, the sequence of each fragment can be put together to deduce the complete amino acid sequence of protein. The details of each stage is as follows-

Figure 38.1: Over-View of the different stages in sequencing of a protein.