ABSTRACT
The number of each type of amino acid in a protein can be determined by acid hydrolysis and separation of the individual amino acids by ion exchange chromatography. The amino acids are detected by colorimetric reaction with, ninhydrin or fluorescamine. The N-terminal amino acid of a protein can be determined by reacting the protein with dansyl chloride or fluorodinitrobenzene prior to acid hydrolysis. The amino acid sequence of a protein can be determined by Edman degradation which sequentially removes one residue at a time from the N terminus. This uses phenyl isothiocyanate to label the N-terminal amino acid prior to its release from the protein as a cyclic phenylthiohydantoin amino acid. Short polypeptides can be sequenced rapidly by fast atom bombardment mass spectrometry. In solid phase peptide synthesis, polypeptides are chemically synthesized by addition of free amino acids to a tethered peptide.
