ABSTRACT
The percentage of each group that was successfully sequenced differed considerably: 51% of the proteins and 74% of the peptides. The conditions required to elute proteins from an Ion-exchange chromatography (IEC) matrix are usually compatible with maintaining native biological or enzymatic activities. The application of reverse-phase chromatography (RPC) for the separation of peptides is now the method of choice in most labs for either mapping or isolation for sequence analysis. Both cation and anion exchangers have proven effective in the purification of bovine pituitary peptides. The two chromatographic modes, Hydrophobic Interaction Chromatography (HIC) and RPC, in fact, compliment each other in a number of ways. The recent availability of suitable anion and cation supports has provided both IEC and chromatofocusing as alternatives to RPC. Size-exclusion chromatography (SEC) may be useful for high-sensitivity applications, such as at an early step of isolation or as a substitute for desalting prior to sequencing.
