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Ernst Klenk (14 October 1896,
Pfalzgrafenweiler Pfalzgrafenweiler is a municipality in the district of Freudenstadt in Baden-Württemberg in southern Germany. The Counts of Tübingen had a large castle located at Pfalzgrafenweiler in the 13th and 14th centuries. Between 1972 and 1975, the mu ...
– 29 December 1971,
Cologne Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western States of Germany, state of North Rhine-Westphalia (NRW) and the List of cities in Germany by population, fourth-most populous city of Germany with 1.1 m ...
) was a German biochemist, known as a pioneer in research on biolipids, their
metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
, and diseases caused by biolipid disorders.


Biography

Klenk's father had a farm and a brewery in the Black Forest. However, Klenk did not want to take over his father's brewery and went to secondary school ( ''Gymnasium'') in Tübingen. After serving in WW I as a soldier from 1914 to January 1919, he studied chemistry at the
University of Tübingen The University of Tübingen, officially the Eberhard Karl University of Tübingen (german: Eberhard Karls Universität Tübingen; la, Universitas Eberhardina Carolina), is a public research university located in the city of Tübingen, Baden-Wü ...
. At the University of Tübingen's ''Institut für Physiologische Chemie'' he in 1923, under the supervision of Percy Brigl (1885–1945), received his ''Promotion'' as
Dr. rer. nat. ''Doctor rerum naturalium'' ( for, , Latin, doctor of natural sciences, lit. 'doctor of the things of nature'), abbreviated Dr. rer. nat., is a doctoral academic degree awarded by universities in some European countries (e.g. Germany, Austria and C ...
; the doctoral dissertation is titled ''Verhalten von Dipeptiden und Elastin zu Phtalsäureanhydrid'' (reaction of dipeptides and elastin to phthalic anhydride). At the ''Institut für Physiologische Chemie'' Klenk was in 1923 appointed to the position of second assistant to the biochemist Hans Thierfelder (1858–1930) and in 1926 completed his
habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including a ...
and was then appointed a ''
Privatdozent ''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualific ...
''. In 1930 he was appointed an professor extraordinaries in the chair of physiological chemistry at the ''Institut für Physiologische Chemie'', which was directed by Franz Knoop after the death of Thierfelder. Klenk joined in 1933 the ''Nationalsozialistische Deutsche Arbeiterpartei'' and in 1934 the ''
Sturmabteilung The (; SA; literally "Storm Detachment") was the original paramilitary wing of the Nazi Party. It played a significant role in Adolf Hitler's rise to power in the 1920s and 1930s. Its primary purposes were providing protection for Nazi ral ...
''. After WW II there was controversy about human tissue samples used by him and other German researchers, such as Berthold Ostertag (1895–1975) and Franz Seitelberger (1916–2007), and by the American physician and neuropathologist Webb Edward Haymaker (1902–1984). Klenk refused an offer from the
University of Marburg The Philipps University of Marburg (german: Philipps-Universität Marburg) was founded in 1527 by Philip I, Landgrave of Hesse, which makes it one of Germany's oldest universities and the oldest still operating Protestant university in the wor ...
to become the successor in the professorial chair vacated by Friedrich Kutscher (1866–1942) and in 1936 was appointed a professor ordinarius at the
University of Cologne The University of Cologne (german: Universität zu Köln) is a university in Cologne, Germany. It was established in the year 1388 and is one of the most prestigious and research intensive universities in Germany. It was the sixth university to ...
. He established the University of Cologne's Institute for Physiological Chemistry of the Medical Faculty and headed the Institute from 1937 to 1967. After WW II he was in charge of rebuilding the destroyed institute, which had been evacuated to Marburg in 1944. From 1947 to 1948 Klenk was from 1947 to 1948 of the medical faculty and from 1961 to 1962 the rector of the University of Cologne. In the early 1960s he was one of the founders of the
University of Bochum The Ruhr University Bochum (, ) is a public research university located in the southern hills of the central Ruhr area, Bochum, Germany. It was founded in 1962 as the first new public university in Germany after World War II. Instruction began in ...
. At the University of Cologne he retired as professor emeritus in 1965. Klenk did research on
phospholipid Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typ ...
s,
glycolipid Glycolipids are lipids with a carbohydrate attached by a glycosidic (covalent) bond. Their role is to maintain the stability of the cell membrane and to facilitate cellular recognition, which is crucial to the immune response and in the connec ...
s,
cerebroside Cerebrosides is the common name for a group of glycosphingolipids called monoglycosylceramides which are important components in animal muscle and nerve cell membranes. They consist of a ceramide with a single sugar residue at the 1-hydroxyl ...
s,
glucocerebroside Glucocerebroside (also called glucosylceramide) is any of the cerebrosides in which the monosaccharide head group is glucose. Clinical significance In Gaucher disease, the enzyme glucocerebrosidase is nonfunctional and cannot break down glucocer ...
s,
sphingosine Sphingosine (2-amino-4-trans-octadecene-1,3-diol) is an 18-carbon amino alcohol with an unsaturated hydrocarbon chain, which forms a primary part of sphingolipids, a class of cell membrane lipids that include sphingomyelin, an important phospholip ...
s,
sphingolipid Sphingolipids are a class of lipids containing a backbone of sphingoid bases, a set of aliphatic amino alcohols that includes sphingosine. They were discovered in brain extracts in the 1870s and were named after the mythological sphinx because ...
s,
glycosphingolipid Glycosphingolipids are a subtype of glycolipids containing the amino alcohol sphingosine. They may be considered as sphingolipids with an attached carbohydrate. Glycosphingolipids are a group of lipids (more specifically, sphingolipids) and are a p ...
s,
ganglioside A ganglioside is a molecule composed of a glycosphingolipid (ceramide and oligosaccharide) with one or more sialic acids (e.g. ''N''-acetylneuraminic acid, NANA) linked on the sugar chain. NeuNAc, an acetylated derivative of the carbohydrate sia ...
s,
plasmalogen Glycerophospholipids of biochemical relevance are divided into three subclasses based on the substitution present at the sn-1 position of the glycerol backbone: acyl, alkyl and alkenyl. Of these, the alkyl and alkenyl moiety in each case form an ...
s, and
polyene In organic chemistry, polyenes are poly- unsaturated, organic compounds that contain at least three alternating double () and single () carbon–carbon bonds. These carbon–carbon double bonds interact in a process known as conjugation, resultin ...
fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...
s. By elucidating the structure of the glucocerebrosides, he pioneered the field of lipidoses (or lipid storage diseases). His research helped to establish the cause of Niemann-Pick’s lipidosis as the storage of large amounts of sphingomyelin in the brain, liver and spleen. He found that cerebroside accumulated in
Gaucher's disease Gaucher's disease or Gaucher disease () (GD) is a genetic disorder A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polyg ...
. In 1935 Klenk discovered a new group of glycosphingolipids in the nervous tissue, which he called gangliosides. (The molecule
GM2 ganglioside In organic chemistry, GM2 is a type of ganglioside. G refers to ganglioside, the M is for monosialic (as in it has one sialic acid), and 2 refers to the fact that it was the second monosialic ganglioside discovered. It is associated with GM2 gang ...
occurs normally but, due to an enzyme defect, builds up pathologically in the cells of victims of
Tay–Sachs disease Tay–Sachs disease is a genetic disorder that results in the destruction of nerve cells in the brain and spinal cord. The most common form is infantile Tay–Sachs disease, which becomes apparent around three to six months of age, with the baby ...
.) Klenk discovered that
N-acetylneuraminic acid ''N''-Acetylneuraminic acid (Neu5Ac or NANA) is the predominant sialic acid found in human cells, and many mammalian cells. Other forms, such as N-Glycolylneuraminic acid, may also occur in cells. This residue is negatively charged at physiolog ...
is a characteristic of
glycoproteins Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycos ...
that are cell receptors for some ( myxoviruses. His work on phospholipids resulted in his proposed structure for plasmalogens: these are not — as
Robert Feulgen Joachim Wilhelm Robert Feulgen (2 September 1884 – 24 October 1955) was a German physician and chemist who, in 1914, developed a method for staining DNA (now known as the Feulgen stain) and who also discovered plant and animal nuclear Nuclear ...
called them — acetal phosphatides, but 1-alkenyl-2-acyl-glycerophospholipids. In the mid-1950s, Klenk resumed the work he had begun two decades earlier on the structure of highly unsaturated fatty acids. He succeeded in classifying many polyenoic acids as 4 basic acid types: palmitoleic, oleic, linoleic,or α-linolenic. His research involved ''in vivo'' studies on the biosynthesis of C20 and C22 polyenoic acids that showed that showed that C20 and C22 polyenoic acids arise through chain lengthening and desaturation of the 4 basic polyenoic acid types. At the beginning of the 1960s, Klenk again made gangliosides the focus of his work. He elucidated the structures of many gangliosides. He was from 1956 to 1959 the vice-president and from 1959 to 1962 the president of the ''Gesellschaft für Biologische Chemie'', which was renamed in 1968 the ''Gesellschaft für Physiologische Chemie'' and in 1995 the ''Gesellschaft für Biochemie und Molekularbiologie'' (Society for Biochemistry and Molecular Biology). He was a member of the editorial board of '' Hoppe-Seylers Zeitschrift für Physiologische Chemie''. Klenk was made ''Doctor mediciniae honoris causa'' (''Dr. med. h. c.'') in 1948 by the University of Cologne. He received in 1953 the Normann Medaille from the ''Deutsche Gesellschaft für Fettforschung'' and in 1958 was elected a member of the
Academy of Sciences Leopoldina The German National Academy of Sciences Leopoldina (german: Deutsche Akademie der Naturforscher Leopoldina – Nationale Akademie der Wissenschaften), short Leopoldina, is the national academy of Germany, and is located in Halle (Saale). Founded ...
. He received the
American Oil Chemists' Society The American Oil Chemists' Society (AOCS) is an international professional organization based in Urbana, Illinois dedicated to providing the support network for those involved with the science and technology related to fats, oils, surfactants, an ...
Award in 1958 and again in 1965. Klenk received in 1964 the inaugural ''Heinrich-Wieland-Preis'', in 1966 inaugural the Stouffer Prize (shared by Harry Goldblatt for independent research),award named after the industrialist Vernon Stouffer (1901–1974) and, posthumously, in 1972 the ''Otto-Warburg-Medaille''. He was since 1937 married to Grete Aldinger (who had studied with him in Tübingen). They had three sons, Hans-Dieter Klenk, Fritz Klenk, and Wolfgang Klenk.


Selected publications


Articles

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Books

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References


External links

* {{DEFAULTSORT:Klenk, Ernst German biochemists University of Tübingen alumni Academic staff of the University of Cologne 1896 births 1971 deaths