December 2010

Bernard L. Horecker (1914 – 2010)

ASBMB Past-president Bernard Leonard Horecker died this past October. He was well know for his contributions to elucidating the pentose phosphate pathway.

Bernard L. HoreckerBernard Leonard Horecker, best known for his contributions to elucidating the pentose phosphate pathway, died on Oct. 9, 2010. He was president of the American Society for Biochemistry and Molecular Biology in 1968.

Horecker was born in Chicago in 1914. He began his training in enzymology in 1936 as a graduate student at the University of Chicago in the laboratory of T. R. Hogness, searching for an enzyme that would catalyze the reduction of cytochrome c by reduced NADP. This marked the beginning of his lifelong involvement with the pentose phosphate pathway.

After earning his doctoral degree, Horecker got a job at the National Institutes of Health in Frederick S. Brackett’s laboratory in the Division of Industrial Hygiene. As part of the war effort, he was assigned the task of developing a method to determine the carbon monoxide hemoglobin content of the blood of Navy pilots returning from combat missions.

When the war ended, Horecker remained at the NIH and returned to research in enzymology. He began to study the reduction of cytochrome c by the succinic dehydrogenase system. This work led to a collaboration with Arthur Kornberg in which the two studied the effects of cyanide on the succinic dehydrogenase system. Cyanide previously had been found to inhibit enzymes containing a heme group, with the exception of cytochrome c. However, Horecker and Kornberg discovered that cyanide did, in fact, react with cytochrome c and concluded that previous groups had failed to perceive this interaction because the shift in the absorption maximum was too small to be detected by visual examination.

Two years later, Kornberg invited Horecker and Leon Heppel to join him in setting up the new Section on Enzymes in the Laboratory of Physiology at the NIH. Their section eventually became part of the new Experimental Biology and Medicine Institute and was later renamed the National Institute of Arthritis and Metabolic Diseases.

Horecker and Kornberg collaborated again, this time on the isolation of NAD (DPN) and NADP (TPN). By 1948, they had amassed a substantial supply of these materials and were able to present Otto Warburg, the discoverer of NADP, with a gift of 25 mg of the coenzyme when he visited the NIH. Horecker also collaborated with Heppel on the isolation of xanthine oxidase from milk, which unexpectedly reduced cytochrome c only in the presence of oxygen, an observation that eventually led to a widely used assay for the detection of the superoxide anion.

For more information

• Read more about Horecker’s life in science at his ASBMB President page.
• Read Horecker’s Journal of Biological Chemistry Reflection.
• Read Horecker’s Journal of Biological Chemistry Classic.

Horecker’s research interests turned to enzymes involved in the oxidation of 6-phosphogluconate, and he demonstrated that this pathway generated ribulose 5-phosphate. He played a key role in the elucidation of the pentose phosphate pathway, which included the discovery of the enzymes transketolase, transaldolase and pentose phosphate 3-epimerase and the identification of sedoheptulose 7-phosphate and erythrose 4-phosphate. His laboratory also was the first to prepare ribulose bisphosphate and ribulose bisphosphate carboxylase, both essential components in the photosynthetic fixation of carbon dioxide by green plants.

In 1958, Horecker left the NIH to assume the microbiology chair at New York University School of Medicine, and in 1963, he moved to Albert Einstein College of Medicine as chairman of the newly formed department of molecular biology.  In 1972, he moved to the Roche Institute of Molecular Biology. Eventually, he became dean of the Weill Cornell Graduate School of Medical Sciences as well as associate dean for research and sponsored programs and professor emeritus of biochemistry at Weill Cornell Medical College. An advocate and exemplar of excellence in research and education, he was instrumental in establishing the tri-institutional M.D.-Ph.D. program at Weill Cornell, the Sloan-Kettering Institute and Rockefeller University.

Horecker’s contributions to science have been recognized with numerous awards and honors, including the American Chemical Society’s Hillebrand Prize (1953), the Washington Academy of Sciences Award for Scientific Achievement in Biological Sciences (1954) and his election to the National Academy of Sciences (1961).

Nicole Kresge ( is the editor of ASBMB Today. 

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