A model of the mass spectrometer expected to arrive in the next few weeks

At the Kresge Center Proteomics Facility in Building I, the anticipated arrival within the next few weeks of a new machine will make the facility unique at Harvard and increase its profile in the ripe field of proteomics.

The machine is called an LCQ Deca XP. It is a mass spectrometer and will allow HSPH researchers, students and post docs to better understand proteins.

Proteomics, the study of proteins, is considered a big frontier in basic biological research. Genes encode proteins, providing the instructions on how to build a protein.

While the number of genes that make up all cells is estimated to be large, the number of proteins those genes encode is thought to be a magnitude larger. For example, the human genome is thought to have roughly 30,000 genes. Those genes may encode an estimated 300,000 proteins.

"Genes per se do not have a function," explained Dieter Wolf, assistant professor of toxicology in the Department of Cancer Cell Biology and director of the Kresge Center Proteomics Facility. "They only have a function if they are translated and transcribed into a protein, so the idea is that by looking at proteins, we can understand what the function of a gene is."

Proteins build cells, organs and tissues. They also serve as hormones, enzymes and antibodies. They are made of chains of amino acids, which are linked together by peptide bonds and are called polypeptides.

Understanding how proteins behave is important not only for basic science research but also because proteins are targets for drug therapies and are biomarkers for disease, said Wolf. But research has not been easy. Proteins can be challenging study subjects, degrading or becoming unstable easily. Extracting every protein from a cell can be very difficult because they all require different conditions for solubilization, said Wolf.

Part of the 2D gel electrophoresis set-up at the Center

The group received word from the National Science Foundation in the spring that their grant application for a mass spectrometer was successful.

The Kresge Center Proteomics Facility already has a set-up for 2D gel electrophoresis, which lays out the protein content of a cell according to its electrical charge and its molecular weight. It allows scientists to differentiate between proteins in a cell; the proteins show up as black dots on a gel.

	Dieter Wolf

The new mass spectrometer at the Kresge Center Proteomics Facility will offer more precise identification. The instrument can determine both peptide mass and sequence.

"That is usually enough to uniquely identify a protein," said Wolf.

Other facilities at Harvard offer mass spectrometry but none provides both 2D gel electrophoresis and this level of mass spectrometry, said Wolf.

Wolf said that one reason the Proteomics Interest Group purchased a mass spectrometer was because the group members wanted to train students and post docs on an emerging technology.

For more information about the Kresge Center Proteomics Facility, visit www.hsph.harvard.edu/proteomics.