Since researchers can now follow only two or three proteins at a time, an expanded fluorescent protein palette would be a big help. "To understand many cellular functions, you would like to follow dozens of different proteins, so the more colors we can develop, the better," says study co-author Steven C. Almo, Ph.D., professor of biochemistry and of physiology & biophysics at Einstein. He is an expert in x-ray crystallography, a method that determines the arrangement of atoms within a protein by striking the protein crystal with a beam of x rays.
The findings reported in the Chemical & Biology paper resulted from a multidisciplinary research effort involving Einstein's Structural Biology Center (where x-ray crystallography studies are carried out) and its Gruss Lipper Biophotonics Center (which develops advanced microscopy techniques to study biological problems related to human disease).
Dr. Verkhusha's laboratory has also developed new red fluorescent proteins that are photoactivatable, meaning that they can be turned on from the dark to the fluorescent state using a short pulse of light. With these versatile probes, researchers can use real-time super-resolution fluorescence microscopy to capture images as small as 15 to 20 nanometers (the scale of single molecules) in living cells. Before such probes were available, super-resolution fluorescence microscopy could be done only in non-living cells.
Recently, one of Dr. Verkhusha's photoactivatable probes allowed Einstein scientists to view individual breast cancer cells for several days at a time to obtain new insights into metastasis, the process by which tumor cells spread to other parts of the body. "Mapping the fate of tumor cells in different regions of a tumor was not possible before the development of photoswitching technology," explains John S. Condeelis, Ph.D., co-chair and professor of anatomy and structural biology, co-director of the Gruss Lipper Biophotonics Center, and the Judith and Burton P. Resnick Chair in Translational Research.
SOURCE Albert Einstein College of Medicine of Yeshiva University
www.einstein.yu