25 Feb 2013, BioSpectrum Bureau , BioSpectrum
Singapore: Researchers at the University of Wisconsin-Madison, US, have found a new way to accelerate a workhorse instrument that identifies proteins. The high-speed technique could help diagnose cancer sooner and point to new drugs for treating a wide range of conditions.
The fastest way to count and identify proteins is to use a mass spectrometer, a precise instrument that measures chemical compounds by mass. "Mass spec is an essential part of modern biology, and most people use it to look at variations in proteins," says Mr Joshua Coon, a professor of chemistry and biomolecular chemistry.
However, because mass spectrometers are expensive and proteins are both numerous and ubiquitous, chemists have recently learned to double up their samples so they can, for example, compare normal tissue to diseased tissue in a single run. Mr Coon has doubled-down on the doubling-up process with a technique that has the potential to run as many as 20 samples at once. The new process, described in the journal Nature Methods, has already gone to work, says Mr Alexander Hebert, a graduate student who is the first author of the new publication.
The team is presently using the technique with John Denu at the Wisconsin Institute for Discovery by looking at mice that lived with or without caloric restriction. Mr Hebert said that, "Caloric restriction is known to increase lifespan in many animals, and scientists are eager to unravel the biochemical pathways that explain this life extension. "Some of these mice have lost a certain gene related to metabolism, so we are comparing four types of tissue all at once. We can look at the brain, liver or heart, and ask, how does the abundance of proteins vary?"
The study of proteins is the forefront of biology, said Mr Coon, and so it's easy to envision uses for a faster, cheaper analytical tool. "We could look for protein differences in cells from 100 different tumors. The proteins might reveal that you are dealing with five or 10 distinct syndromes in this seemingly-identical cancer, which could suggest treatments that are more tailored to the individual. If you compare proteins in normal versus tumor tissue, you might find a certain protein at uncommonly high concentrations, or was modified in certain ways. You might identify a protein that would help diagnose this cancer sooner or you might identify a protein that is so vital to the cancer that it would make an ideal target for a new drug."