Herman Kalckar

Infobox Scientist
name = Herman Kalckar
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birth_date = March 26 1908
birth_place = Copenhagen, Denmark
death_date = death date and age|1991|5|17|1908|3|26
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field = Biochemistry
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Herman Moritz Kalckar (1908 -1991) was a Danish biochemist who pioneered the study of cellular respiration. [ [http://query.nytimes.com/gst/fullpage.html?res=9D0CE4DC1138F931A15756C0A967958260 Obituary - "Herman Kalckar, 83, Metabolism Authority"] New York Times, May 22, 1991] [cite journal |author=Kalckar HM |title=50 years of biological research--from oxidative phosphorylation to energy requiring transport regulation |journal=Annu. Rev. Biochem. |volume=60 |issue= |pages=1–37 |year=1991 |pmid=1883194 |doi=10.1146/annurev.bi.60.070191.000245] He trained as a medical doctor at the University of Copenhagen but later moved to America, becoming a professor of biology at Johns Hopkins University.

In his work in Denmark, Kalckar showed that phosphate compounds could provide energy, by demonstrating that in frog muscles where glycolysis had been inhibited with iodoacetate, muscular contraction continued for a short period using phosphocreatine as a source of energy. [cite journal |author=Kalckar HM |title=Origins of the concept oxidative phosphorylation |journal=Mol. Cell. Biochem. |volume=5 |issue=1-2 |pages=55–63 |year=1974 |pmid=4279328 |doi=10.1007/BF01874172] This suggested for the first time that phosphate compounds acted as a link between catabolism and anabolism. [ [http://www.nap.edu/readingroom/books/biomems/hkalckar.html Herman Moritz Kalckar] Eugene P. Kennedy "National Academy of Sciences Biographical Memoirs" Volume 69, 1996] These studies were done in close collaboration with Fritz Albert Lipmann.

In America, Kalckar worked with Sidney Colowick and discovered adenylate kinase in 1942, purifying this enzyme from muscle extracts. [cite journal |author=Kalckar HM. |title=The enzymatic action of myokinase |journal=J. Biol. Chem. |volume=143 |issue=1 |pages=299–300 |year=1942 |url=http://www.jbc.org/cgi/reprint/143/1/299] Further work on nucleotide metabolism allowed him to identify nucleoside phosphorylase, a key enzyme in nucleotide salvage pathways. [cite journal |author=Kalckar HM. |title=Enzymatic synthesis of a nucleoside |journal=J. Biol. Chem. |volume=158 |issue=3 |pages=723–724 |year=1945 |url=http://www.jbc.org/cgi/reprint/158/3/723]

Moving on from nucleotides, Kalckar switched his attention to the enzymes involved in galactose metabolism. Here, he characterised galactose-1-phosphate uridylyltransferase and identified the cause of the human metabolic disease galactosemia as a defect in this enzyme. [cite journal |author=Kalckar HM, Braganea B, Munch-Petersen A. |title=Uridyl Transferases and the Formation of Uridine Triphosphate : Uridyl Transferases and the Formation of Uridine Diphosphogalactose |journal=Nature |volume=172 |issue=4388 |pages=1013–62 |year=1953 |doi=10.1038/1721038a0] [cite journal |author=Isselbacher KJ, Anderson EP, Kurahashi K, Kalckar HM |title=Congenital galactosemia, a single enzymatic block in galactose metabolism |journal=Science |volume=13 |issue=123 |pages=635–6 |year=1956 |pmid=13311516 |doi=10.1126/science.123.3198.635]

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