Milestones in the techniques and methodology of polypeptide structure determination include the determination of the sequence of insulin by Sanger in 1951 (I) and the introduction of the repeti- tive degradation of proteins with phenylisothiocyanate by Edman in 1959 (2). The automation of Edman chemistry (3) played a major role in the determination of polypeptide structures. Important modifications of Edman chemistry include the solid-phase approach...