One of the teams, led by Akhilesh Pandey from Johns Hopkins University, identified and annotated proteins encoded by 17,294 genes -- that accounts for around 84 percent of all the genes in the human genome that are predicted to encode proteins (that number is estimated at 19,629, if you’re curious). The team extracted proteins from samples of 30 different tissues, then used enzymes to cut them into small pieces called peptides. They ran the peptides through a series of instruments to identify and measure their relative abundance.
The other team, led by Bernhard Kuster of Technische Universit?t München (TUM) in Germany, assembled protein evidence for over 18,000 genes (or 92 percent of the entire proteome) by compiling raw mass spec data from databases and other analyses that were already available. These include a core of 10,000–12,000 proteins expressed in several different tissues, and to fill in the gaps, they generated their own mass spec data by analyzing 60 human tissues, 13 body fluids, and 147 cancer cell lines.
“It is estimated that the human body may contain over two million proteins, coded for by only 20,000 - 25,000 genes. The total number found in terran biological organisms is likely to exceed ten million”
