Walther Stoeckenius, 1921 – 2013

Editor’s note: Walther Stoeckenius, emeritus professor at the University of California, San Francisco, died in August. He was 92. In recognition of his contributions and to draw attention to two of his seminal publications in the Journal of Biological Chemistry, the journal in 2011 published a “Classic” article about his life and work. Here, we’ve republished that article (edited for length, clarity and style).

Walther Stoeckenius Walter Stoeckenius

In 1971, Walther Stoeckenius discovered that Halobacterium halobium contains a purple pigment that is chemically similar to rhodopsin and works as a light-driven proton pump. This discovery set Stoeckenius on a research path centered on bacteriorhodopsin, which included the creation of a bovine-soybean-halobacteria chimera that produced ATP when exposed to light and the discovery of a class of proteins that are phosphorylated in a light-dependent manner.

 Stoeckenius was born in 1921 in Giessen, Germany. He earned his M.D. from the University of Hamburg in 1950, after which he spent 18 months doing clinical work as an intern. In 1952, he began postdoctoral work at the Institute for Tropical Medicine in Hamburg, using electron microscopy to study the development of poxviruses. Two years later, he joined the University of Hamburg as an assistant professor and became a docent for the pathology department in 1958. At Hamburg, Stoeckenius continued to use electron microscopy to explore the fine structure of cells and the lipid membrane.

In 1959, Stoeckenius left Germany to become a research associate in Keith Porter’s laboratory at The Rockefeller University. After a few months, he became an assistant professor at Rockefeller, remaining there for eight years and eventually becoming an associate professor. He continued to work on membrane structure, studying H. halobium, until he accepted a professorship at the University of California, San Francisco, in 1967.

In San Francisco, Stoeckenius focused on biochemical techniques rather than electron microscopy. In collaboration with Dieter Oesterhelt, he discovered that H. halobium contains a purple pigment (bacteriorhodopsin) that is chemically similar to rhodopsin and plays an important role in light energy storage in halobacteria, working as a light-driven proton pump.

This discovery led to a collaboration with Efraim Racker in which Stoeckenius and Racker created a thoroughly unnatural vesicle. As reported in their 1974 Journal of Biological Chemistry article, they used sonication to recombine membrane lipids from soybeans, bacteriorhodopsin from halobacteria, and ATPase from beef mitochondria. The resulting artificial vesicles produced ATP when exposed to light. The chimeric vesicles also formed a simple model system for a biological proton pump capable of generating ATP from ADP and Pi.

Stoeckenius continued to study bacteriorhodopsin and its light-driven proton uptake in bacteria. As reported in a 1980 JBC paper, he discovered that phosphorylation is regulated by light absorbed by bacteriorhodopsin. Using [32P]orthophosphate pulse labeling, Stoeckenius and John Spudich identified a class of phosphoproteins in H. halobium. Exposing labeled whole cells to light resulted in rapid dephosphorylation of two of the proteins, which were rapidly rephosphorylated upon darkening of the cells. The light sensitivity of the proteins was responsive to the presence of retinal, indicating that the dephosphorylation depended on rhodopsinlike (retinal-containing) photoreceptors.

Stoeckenius was elected to the National Academy of Sciences in 1978.