Bringing Electron Paramagnetic Resonance (EPR) to Biochemistry: the Work of Helmut Beinert

Abstract

Helmut Beinert (1913–2007) was born in 1913 in a small town in Baden, Germany, named Lahr. He attended a classical German gymnasium in Heidelberg and received his Abitur in 1932, graduating in Greek and Latin. Speaking about his early education, Beinert said, “I was certainly not predestined or even prepared to enter the world of frontline biochemical research. But in close neighborhood, there was the Kaiser Wilhelm Institute (KWI), and one day the children of two KWI directors, Prof. Meyerhof (Physiology), and Prof. Hausser (Physics), suddenly appeared in our school” (1Beinert Ghisla S. Kroneck P. Macheroux P. Sund H. Flavins and Flavoproteins. R. Weber Agency for Scientific Publications, Berlin1999: 3Google Scholar). Around the time of Beinert's final exams, KWI director Richard Kuhn organized a meeting on biological oxidation and invited many prominent scientists, including Hans Fischer, James Franck, Fritz Haber, J. B. S. Haldane, David Keilin, Hans Krebs, Carl Neuberg, Otto Warburg, Richard Willstätter, and Journal of Biological Chemistry (JBC) Classic author Otto Meyerhof (2Meyerhof O. Junowicz-Kocholaty R. J. Biol. Chem. 1943; 149 (JBC Classics): 71-92Abstract Full Text PDF Google ScholarMeyerhof O. J. Biol. Chem. 1945; 157: 105-120Abstract Full Text PDF Google ScholarMeyerhof O. Oesper P. J. Biol. Chem. 1947; 170: 1-22http://www.jbc.org/cgi/content/full/280/4/e3Abstract Full Text PDF Google Scholar). This was a turning point in Beinert's life, and it impressed him so much that he decided to study chemistry in Heidelberg and Leipzig. In 1943, he received his doctoral degree from the University of Leipzig while performing his thesis research in Kuhn's laboratory at the KWI. After graduating, Beinert remained at the KWI until 1945, when he went to the United States and spent several years as a biochemist at the U.S. Air Force School of Aviation Medicine in Randolph, Texas. In 1950, he joined the Institute for Enzyme Research at the University of Wisconsin in Madison; in 1955, he became a U.S. citizen; and in 1962, he was promoted to full professor. Beinert remained at the University of Wisconsin until he retired in 1985. He was subsequently recruited as a Distinguished Scholar in the Department of Biochemistry at the Medical College of Wisconsin in Milwaukee, where he continued his research until his death. Beinert is probably best known for bringing electron paramagnetic resonance (EPR) to biochemistry. The two JBC Classics reprinted here reflect some of his early work that was done at a time when low temperature EPR was being applied to redox-active, metal-containing enzymes. The first Classic paper reports on EPR studies on the mechanism of action of the metalloflavoprotein dihydroorotate dehydrogenase from Zymobacterium oroticum. Victor Aleman, who was a graduate student with JBC Classic author Philip Handler (3Handler P. Dann W.J. J. Biol. Chem. 1942; 145 (JBC Classics): 145-153Abstract Full Text PDF Google ScholarLeder I.G. Handler P. J. Biol. Chem. 1951; 189: 889-899http://www.jbc.org/cgi/content/full/279/48/e8Abstract Full Text PDF PubMed Google Scholar), purified the enzyme and brought the compound to Madison where he analyzed it with Beinert's postdoc, Graham Palmer. They incubated the enzyme with the reducing substrates DPNH and dihydroorotate and described the changes in EPR signals and optical spectra. In a second paper, published back-to-back with the Classic, Aleman, Handler, Palmer, and Beinert report on the kinetics of the reaction (4Aleman V. Handler P. Palmer G. Beinert H. Studies on dihydroorotate dehydrogenase by electron paramagnetic resonance spectroscopy. II. Kinetic studies by rapid freezing.J. Biol. Chem. 1968; 243: 2569-2578Abstract Full Text PDF PubMed Google Scholar). In the second JBC Classic reprinted here, Beinert and colleagues studied aldehyde oxidase from rabbit liver using EPR. Handler's postdoc, K. V. Rajagopalan, purified the enzyme, which contained molybdenum (he went on to discover and determine the structure of a molybdenum cofactor that he named molybdopterin, which will be the subject of a future JBC Classic). Rajagopalan brought the samples to Beinert's laboratory and analyzed them with Palmer. They reduced the enzyme with a substrate, observed the signal changes, and were able to demonstrate an intramolecular electronic interaction between Mo(V), flavin, and an iron-sulfur cluster. This paper was also followed by one which used rapid-freeze quenching to obtain kinetic data on the reaction (5Rajagopalan K.V. Handler P. Palmer G. Beinert H. Studies of aldehyde oxidase by electron paramagnetic resonance spectroscopy. II. Kinetic studies by rapid freezing.J. Biol. Chem. 1968; 243: 3797-3806Abstract Full Text PDF PubMed Google Scholar). In recognition of his contributions to science, Beinert received numerous awards and honors. These include the National Institutes of Health Research Career Award (1963), the Alexander von Humboldt Foundation Senior Scientist Award (1981), the British Biochemical Society's Keilin Medal (1985), the Federal European Biochemical Society's Krebs Medal (1989), the German Society for Biological Chemistry's Warburg Medal (1994), and the American Society for Biochemistry and Molecular Biology's Lipmann Plaque (1993). In 1980, Beinert was inducted into the National Academy of Sciences.