A human proteome project with a beginning and an end

Research activities centered on the ensemble of and individual human proteins have taken on numerous guises, some of which fall under the banner of what could be defined as a Human Proteome Project (HPP). However, the latter has yet to take-on the apparent global focus of its predecessor, the Human Genome Project. The reasons for this are both financial and technical. The disparate properties afforded to each protein by a 20-letter code render a single unifying approach difficult to implement, while the current limit of analytical detection has yet to deliver an entire proteome for even the simplest of microbes. The situation is complicated further by the fact that low abundance proteins dominate within any living cell. Thus, enhancement of signal-to-noise ratio by affinity ligands becomes of paramount importance if whole-organism proteomics is to be realized. The generation of such ligands (molecules exhibiting desirable affinity and selectivity for target) could provide the necessary focus and a task list with a definable beginning and end. Such a finite task list is considered essential if an HPP might one day deliver global coverage on a scale seen currently for the total DNA sequence of some 200 living organisms.