Chemistry, Mass Spectrometry and Peptide-Mass Databases: Evolution of Methods for the Rapid Identification and Mapping of Cellular Proteins

Abstract

Large-format 2D gel electrophoresis systems have been developed that are capable of resolving several thousand cellular proteins in a matter of days [1,2]. For a number of years, a combination of Edman microsequence analysis and identification of proteins by staining with specific antibodies has been used to systematically categorize proteins and establish cellular databases [3–5]. There are, however, significant problems associated with these approaches. Most resolved proteins are only present in the low- to upper-femtomole range, significantly below the level at which automated sequencers can reliably operate [6, 7]. The relatively slow speed of the Edman process (one or two samples per machine per day) also means that the sheer number of proteins is too great to permit large-scale characterization within any useful period of time. The use of monoclonal antibodies, whilst both rapid and extremely sensitive, requires the ready availability of a large pool of antibody probes