A Metal Detector to Study Diseases

Zinc remains a mystery metal to scientists who study its role in health problems. They are just beginning to fathom how the body keeps levels of zinc under the precise control that spells the difference between health and disease.

“The question of how much zinc is available in a cell has emerged at the forefront of chemical biology”, said Amy R. Barrios, Ph.D., of the University of Southern California, Los Angeles.

“We believe this new technique can help us understand how zinc is involved in plaque formation in Alzheimer’s disease, how prolonged seizures or stroke kill brain cells, and how the cell normally allocates zinc to different proteins,” said Richard B. Thompson, Ph.D. of the department of biochemistry and molecular biology, University of Maryland School of Medicine, Baltimore.

Thompson explained that almost all zinc inside cells is incorporated into proteins, where it plays many vital roles. “We know that if there is much zinc in the cell that is not attached to protein or otherwise encapsulated — so-called ‘free zinc’ — the cell is stressed or may be undergoing programmed cell death. This has been observed in animal models of epilepsy and stroke.”

The technique uses a special protein molecule that has been re-engineered to report when zinc becomes stuck to it as a change in luminescence that can be seen in the microscope. This protein, originally found in blood cells, is very selective, recognizing tiny levels of free zinc even in the presence of the million-fold higher levels of other metals present in cells, such as calcium or magnesium.

Because proper zinc levels are so important in health and disease, scientists have been seeking ways of measuring zinc inside and outside of cells for more than a decade.

COMPAMED.de; Source: American Chemical Society