Herman Moritz Kalckar

from Wikipedia, the free encyclopedia

Herman Moritz Kalckar (born March 26, 1908 in Copenhagen ; † May 17, 1991 in Cambridge (Massachusetts) ) was a Danish biochemist who had researched the fundamental relationships between cellular respiration . He made a major contribution to the progress of biochemistry in the 20th century, as a pioneer in bioenergy research, developer of novel enzyme assays , discoverer of galactose metabolism in both microorganisms and animal tissue, and discoverer of elevated strontium -90 levels in, which correlated with atomic bomb tests Children's milk teeth.

Copenhagen spring conference 1932

Childhood and youth

Kalckar grew up in a "Jewish-Danish middle-class family" who had lived in Denmark for several generations. The family was not wealthy, but they belonged to the educated middle class. His father, Ludvig Kalckar, was a businessman with a strong interest in the theater, especially in the work of Henrik Ibsen . His mother, Bertha Rosalie (née Melchior), brought him close to French and German authors such as Gustave Flaubert , Marcel Proust , Johann Wolfgang von Goethe , and Heinrich Heine . Kalckar writes that during this time his “interest in humanistic education” flourished.

In his autobiography he mentions his early upbringing only in passing. He describes biology classes in high school as "a bit rigid". However, he was impressed by "some extraordinary demonstrations on human physiology" by August Krogh , a professor of physiology at the University of Copenhagen, Nobel Prize winner in 1923 for his description of capillary blood flow and its regulation. This experience had a major influence on Kalckar's later research interests.

Early scientific work

Kalckar studied medicine at the University of Copenhagen. In 1933 he began his doctoral thesis at the Institute of Physiology with Ejnar Lundsgaard (1899–1968). With his work he prepared the basis for research into " oxidative phosphorylation ", a fundamental principle of biochemistry. During this time Lundsgaard became a full professor of physiology. His successor as Kalckar's doctoral supervisor was Fritz Albert Lipmann , who had to flee Germany shortly before . Later, Kalckar and Lipmann independently developed concepts of "high-energy binding" and for adenosine triphosphate (ATP) as a "universal energy carrier".

Kalckar carried out research during a period of important biochemical discoveries, which he himself made a decisive contribution to. Until 1932 there was a consensus among physiologists that muscle contraction always takes place with the formation of lactate , the product of glycolysis . However, his teacher Lundsgaard had already recognized that even when glycolysis is completely inhibited with iodine acetate, the contraction of a frog muscle is maintained to a limited extent, and that the breakdown of creatine phosphate provides the energy for this. Based on this, Kalckar discovered in 1934 that the phosphorylation of creatine to creatine phosphate is oxygen-dependent: In his key experiment with kidney cell extracts , when glycolysis was prevented, he observed the consumption of oxygen and inorganic phosphate with the simultaneous formation of adenosine triphosphate in a Warburg apparatus . With this he succeeded in proving the “oxidative phosphorylation”, which is the basis of the fundamental biochemical process of cell respiration. Kalckar's early experiments also provided evidence of the formation of phosphoenolpyruvate from fumaric and malic acid , later the crucial finding in the elucidation of gluconeogenesis from products of the Krebs cycle . His doctorate in medicine took place in January 1939 in Copenhagen.

Further scientific career

In the spring of 1939 he went to the California Institute of Technology in Pasadena as a Rockefeller Fellow . From 1940 to 1945 he worked in St. Louis and New York , where he met famous biochemists of his time such as Linus Pauling , Gerty Cori , Carl Cori , Sidney Colowick (with whom he discovered adenylate kinase ) and Max Delbrück . At the end of 1945 he returned to Lundsgaard's laboratory at the University of Copenhagen, where he worked on nucleoside phosphorylation. He later explored the biochemical conversion of galactose-1-phosphate to glucose-1-phosphate with uridine triphosphate as a cosubstrate ; In doing so, he contributed to the deciphering of the clinical causes of the inherited galactosemia : The underlying genetic defect led to a deficiency in galactose-1-phosphate uridyltransferase . While working in Baltimore, he deepened his research on nucleoside phosphorylation and carbohydrate metabolism. Here in 1958 he also initiated investigations into the connection between the atomic bomb tests, which were often carried out at the time, and strontium-90 contamination in the milk teeth of children, which later led to the halt of nuclear weapon tests through public sympathy . In 1961 he succeeded Fritz Lipmann as Professor of Biochemistry at Harvard Medical School and Head of the Laboratory for Biochemical Research at Massachusetts General Hospital . He was an honorary member of scientific organizations, including the National Academy of Sciences since 1959 and the American Academy of Arts and Sciences since 1961 .

Kalckar's first marriage to the musician Vibeke Meyer ended in divorce in 1950. In his second marriage he married the biologist Barbara Wright, with whom he had three children. In 1968 he married the widowed Agnete Fridericia Laursen, his third marriage.

Individual evidence

  1. Obituary - "Herman Kalckar, 83, Metabolism Authority" New York Times, May 22, 1991
  2. Kalckar HM: 50 years of biological research-from oxidative phosphorylation to energy Requiring transport regulation . In: Annu. Rev. Biochem. . 60, No. 1, 1991, pp. 1-37. doi : 10.1146 / annurev.bi.60.070191.000245 . PMID 1883194 .
  3. Herman Kalckar: An International Milk Teeth Radiation Census . In: Nature Publishing Group (ed.): Nature . 182, Aug. 2, 1958, pp. 283-284. bibcode : 1958Natur.182..283K . doi : 10.1038 / 182283a0 . Retrieved December 5, 2014.
  4. Kalckar, 1991
  5. Kalckar, 1991
  6. Jaenicke, Lothar , 2008, Lipmann, Fritz Albert in Encyclopedia.com, accessed on July 10, 2018
  7. Singleton, R. Jr., 2008, Kalckar, Herman Moritz Encyclopedia.com.Retrieved July 9, 2018
  8. HM Kalckar: Phosphorylation in Kidney Tissue . In: Enzymologia . 2, 1937, pp. 47-53.
  9. HM Kalckar: The Nature of Phosphoric ester Formed in Kidney Extracts . In: Biochemical Journal . 33, No. 5, 1939, pp. 631-641.
  10. Kalckar HM: Origins of the concept oxidative phosphorylation . In: Mol. Cell. Biochem . 5, No. 1-2, 1974, pp. 55-63. doi : 10.1007 / BF01874172 . PMID 4279328 .
  11. Kalckar, HM Biological phosphorylations: development of concepts . Prentice-hall, Englewood Cliffs NJ, 1969, pp. 171-172
  12. ^ Eugene P. Kennedy, 1996, Herman Moritz Kalckar 1908-1991, a biographical memoir , PDF, National Academies Press, Washington DC.Retrieved July 10, 2018