September 3, 2001
$1 million grant will support research on the environmental toxicology of trace metals
By Tim Stephens
Faculty, researchers, and students in the Departments of Environmental Toxicology, Chemistry and Biochemistry, Ocean Sciences, Earth Sciences, Ecology and Evolutionary Biology, and Molecular, Cell, and Developmental Biology will use the new equipment. Russell Flegal, professor and chair of environmental toxicology, will coordinate the award from the W. M. Keck Foundation.
"This award builds on the strengths of the UCSC campus for interdisciplinary research on trace metals in the environment," Flegal said, noting that the grant names 15 principal investigators in six departments.
Studies by UCSC researchers have contributed to many advances in understanding the biogeochemical cycles, bioavailability, toxicity, protein regulation, and biological functions of metals. For example, UCSC scientists made the first measurements of many trace metal contaminants in a variety of oceanic, estuarine, and freshwater environments, including San Francisco Bay. They used measurements of stable lead isotopes to fingerprint and trace natural and industrial lead in the environment and in organisms. And they developed and refined standard procedures for measuring lead and other toxic metals in water and for measuring lead exposure in infants, children, and other critical populations.
The largest portion of the W. M. Keck Foundation grant will go toward the purchase of a $750,000 instrument called a multi-collector inductively-coupled plasma mass spectrometer (ICP-MS). This is a new and improved version of an instrument that has played a key role in trace metals research at UCSC since 1995, when the campus was the first institution in the United States to acquire a high-resolution ICP-MS.
"With the new ICP-MS, we will be able to do analyses that were previously not possible, such as looking at the isotopic fingerprints of elements like copper and chromium," Flegal said. "This will allow us to fingerprint the sources of pollution and track the movements of these trace metals through the environment and through organisms."
The grant will also support research on mercury pollution through the purchase of specialized equipment for studying mercury in the environment and mercury toxicity in organisms. Mercury occurs in several different forms in the environment, of which the most toxic is methylmercury. The new equipment will be used to accurately measure methylmercury concentrations in the parts-per-quadrillion range and to follow the transformations of mercury from one form to another.
A third area of research supported by the grant is the identification of the protein targets of toxic metals. The most common mechanism underlying metal toxicity is the alteration of the amounts and functions of specific proteins within the cells of an organism. UCSC researchers are currently investigating the protein targets of copper, lead, and manganese.
New analytical techniques enable researchers to conduct large-scale analyses of all of the proteins from a cell or tissue (or even, in the case of small organisms, the whole organism). From a single sample, researchers can isolate, identify, and quantify thousands of proteins. They can also compare samples to see how protein levels change under different conditions, said Anthony Fink, professor of chemistry and biochemistry and a principal investigator on the grant.
This approach, known as "proteomics," has widespread applications. The W. M. Keck Foundation grant will allow the development of a new proteomics facility at UCSC. The facility will be used in research on the interactions of metals and proteins, and will also support a broad range of other research projects on protein functions and interactions, Fink said.
"For example, we would like to know which proteins in an organism increase or decrease in response to exposure to a toxic element, because that gives us an idea about what might be going on at the molecular level," Fink said. "There are many different areas of biomedical science where we would like to apply these techniques."