A Second Generation Solid-phase Protein Sequencer: The Prosequencer™

Abstract

The solid-phase version of the Edman degradation, first described over 20 years ago (Laursen, 1966) and later automated (Laursen, 1971), takes advantage of the principle that proteins which are covalently linked to an insoluble matrix can readily be separated, without losses, from reagents and reaction products. The first commercial solid-phase sequencers were introduced in the early 1970’s and improvements in the technique, primarily in methods of protein immobilization, continued for several years more (Laursen and Machleidt, 1980). With the introduction (Hewick et al 1981) of the gas-phase protein sequencer, interest in the solid-phase technique declined, primarily because of the microsequencing capabilities of the newer instrument and because the protein immobilization steps were not required. Recently, however, there has been a resurgence of interest in solid-phase chemistry because of its advantages as a method for immobilizing proteins electroeluted from polyacrylamide gels and for preventing losses of material with ultramicrosequencing techniques (Aebersold et al 1988).