The basic principle of amino acid sequence analysis is Edman degradation, which mainly involves four processes: coupling, hydrolysis, extraction and conversion. First of all, the use of phenyl isositate in pH9.0 alkaline conditions to treat protein sin, PITC and peptide chain N-end amino acid residual reaction, the formation of phenyl-aminothia-agent, i.e. PTC-peptide.
Then PTC-peptides are treated with trifluoroacetic acid, n-end amino acid residual peptide bonds are selectively cut off, releasing the amino acid residue of the pyridoxonin aniline derivatives. The derivative is then extracted from the reaction solution with an organic solvent and the peptide from an N-end amino acid residue is left in the solution. Extracted pyridine aniline derivatives are unstable, acid action, and further ringing, forming a stable phenylracetythire derivative, i.e. PTH-amino acid. The peptides left in the solution with a reduction in the residue of an amino acid are repeated to perform the above reaction process, and the entire sequencing process is now automated through a sequencer.