Profile of Chikashi Toyoshima

When water is suddenly cooled to temperatures below –140°C, by careful methods such as plunging it into a bath of liquid nitrogen, it forms an amorphous structure that is more like a glass than a crystal. Called vitreous ice, this substance cannot be found in nature but can be used to preserve samples for use with an electron microscope. When biophysicist Chikashi Toyoshima first heard of this technique in graduate school at the University of Tokyo, he knew immediately it was a powerful tool to help reveal the structure of biological samples that would otherwise be crushed in the vacuum of electron microscopes. He traveled across the Pacific to learn the technique in California and eventually used the technique to determine the structure of membrane proteins in tubular crystals, providing images of these biological structures for the first time. Throughout his career, Toyoshima has combined knowledge of mathematics, physics, and biology to reveal atomic structures of biological samples. Now a professor at the Institute of Molecular and Cellular Biosciences at the University of Tokyo and elected to the National Academy of Sciences as a Foreign Associate in 2005, Toyoshima continues to investigate the structures of proteins through a variety of methods. In his Inaugural Article, published in a recent issue of PNAS (1), Toyoshima and his colleagues presented a crystal structure of Ca2+-ATPase and discussed the role that proton countertransport plays in maintaining the enzyme's structural integrity. Toyoshima grew up in post-World War II Japan in the small town of Honjo, in the prefecture of Akita. Elementary-school education in Honjo was “extraordinary,” Toyoshima says, describing the system as “enthusiastic in developing children's ability in science, writing, sports, and arts. In a way, it was very experimental.” Toyoshima and his brother, who was 3 years ahead of him in …