Each protein has a characteristic number and sequence of amino acid residues. The primary structure of a protein determines how the protein folds into a unique three-dimensional structure secondary, tertiary, and quaternary structures, which in turn determines the biological function of the protein. A wealth of information such as function, structure and evolutionary history of a protein can often be obtained from the amino acid sequence of a protein. The protein sequencing services for protein drugs at Creative Proteomics de novo protein sequence analysis https://www.creative-proteomics.com/pronalyse/protein-sequence-analysis.html