As biochemists during the 1970s delved into the protein chemistry of cell signaling, cycling, and adhesion, they ran into two major obstacles: getting enough purified material for some proteins, and the low molecular weights of others. Interferon, for example, was so difficult to purify that it took more than two decades before its structural characterization. And tiny proteins like angiotensin II (8 amino acids) and the antidiuretic hormone vasopressin (9 amino acids) produced hard-to-interpret protein signatures.
Biochemists were constantly pushing the limits of technology to couple, cleave, extract, and sequence peptides with better sensitivity. Pehr Edman, in 1950, developed a chemical degradation process for amino acid sequencing and built the first automated "sequenator" for that task in 1967. Richard Laursen, at Boston University, improved on Edman's concept in 1971 by immobilizing the study sample on a...