ABSTRACT
Since the introduction of phenylisothiocyanate (PITC) for the sequential degradation of proteins and peptides by Edman, this reagent has found widest application in the structure analysis of polypeptides. This chapter draws conclusions about future design of Edman-type reagents for advanced manual and the different automatic sequencing techniques. The excellent fluorescent properties and stability of the derivatives add to the quality of PITC homologous Edman-type reagent and serve as a possibility for further enhanced micro-sequencing at the low picomole level. Dimethylaminoazobenzene isothiocyanate (DABITC) has found much application in microsequence analysis of peptides and proteins, especially for manual sequencing, since the DABITC/PITC double coupling method was introduced. Clear spots of individual degradation cycles can be obtained, thus rendering Fluorescein-isothiocyanate (FITC)/PITC technique useful for manual microsequence analysis. The adaptation of the most suitable chemistry in microsequence analysis is still an open question and leaves a wide field of possible strategies for further development.
