In 1981, Hunt and colleagues pioneered the use of tandem mass spectrometry--an arrangement of two spectrometers in series--to determine the structure of proteins. The protein is first degraded using standard biochemical techniques into a group of peptides, each containing up to 25 or 30 amino acids. Each peptide is placed in the mass spectrometer, where it is broken up via high-energy collision with argon atoms. The pieces that result are then weighed on a millisecond timetable. When the process is applied to all of the fragments, the sequence of the amino acids can be deduced through calculations. Linking two mass spectrometers makes it possible to rapidly weigh pairs of protein fragments differing in length by only one amino acid.
Hunt says that his research can lead to an improved understanding of the immune system. When the body becomes infected with a virus, he explains, "fragments, called peptides, of viral proteins ...
