Albrecht Kossel

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Albrecht Kossel

Albrecht Kossel (born September 16, 1853 in Rostock , † July 5, 1927 in Heidelberg ) was a German physician , physiologist and biochemist . He was awarded the Nobel Prize in Physiology or Medicine in 1910 .

Live and act

Family grave in the Bergfriedhof (Heidelberg) in Section X.

Albrecht Kossel was the eldest son of the merchant, ship owner , bank director and Prussian consul Karl Albrecht Kossel and Klara, née. Jeppe. Albrecht Kossel was married to Luise, b. Holtzmann, the daughter of Adolf Holtzmann . The marriage had a daughter and a son, the physicist Walther Kossel , who discovered the specific interference phenomenon of X-rays on crystals.

Kossel attended high school in Rostock and began studying medicine at the newly founded University of Strasbourg in 1872 . There he was particularly influenced by the lectures given by Heinrich Anton de Bary , Heinrich Wilhelm Waldeyer , August Kundt , Adolf von Baeyer and above all Felix Hoppe-Seyler . After another four semesters at the University of Rostock , he passed his last medical exam there in 1877 and was awarded a Dr. med. PhD .

From 1877 he was an assistant at Hoppe-Seyler in Strasbourg and completed his habilitation in physiological chemistry and hygiene in 1881. In 1883 Emil du Bois-Reymond appointed him head of the chemical department of the Berlin Institute for Physiology . Here he was also appointed associate professor of the medical faculty. In 1895 Kossel accepted a call to the chair of physiology at the Philipps University of Marburg and became director of the physiological institute there. In 1901 he accepted a position at the Ruprecht-Karls-Universität Heidelberg , as the successor to Wilhelm Friedrich Kühne and Hermann von Helmholtz . Until 1924 he headed the Physiological Institute there. After that he was in charge of the Institute for Protein Research, which he founded in 1920, until his death. Kossel was put in charge of the 7th International Physiological Congress, which took place in Heidelberg in 1907. In 1910 he was awarded the Nobel Prize in Physiology or Medicine .

Kossel continued to live in Heidelberg after his retirement. The family grave is located in the Heidelberg mountain cemetery .

Scientific fields of work

The discovery of the nucleobases

In 1878 Kossel began to continue the work of Friedrich Miescher in Strasbourg . In 1869 in Felix Hoppe-Seyler's laboratory in Tübingen, Miescher had obtained a previously unknown, phosphorus-containing substance from the isolated cell nuclei of the leukocytes of the pus, which he called nuclein. Kossel was able to prove that tissues and organs rich in cell nuclei also contain more nucleic phosphoric acid. In addition, targeted starvation experiments on chickens and pigeons showed that the nucleus is not a reserve substance. The amount of nuclein changed little, regardless of whether an organism was starving or not. From this, Kossel concluded that the function of the nuclein is more to be sought in the formation of new tissue. In 1883 he was able to prove that guanine is a cleavage product of the nuclein obtained from goose blood. Guanine has been known since 1844 as a nitrogen-rich base that accumulates in the excrement of mammals and birds. The first findings on the occurrence of guanine in the nucleus had been around since 1874. They went back to the Swiss chemist Jules Piccard , who had examined the "nucleic acid of salmon sperm" (nucleic acid) when asked by Friedrich Miescher. On January 12, 1885, Kossel reported to the Berlin Chemical Society about an important discovery: He was able to isolate a nitrogen-rich base with the molecular formula C 5 H 5 N 5 from a large amount of bovine pancreas , for which he derived from the Greek word " aden ”for gland that suggested the name adenine . A little later, Kossel also found it to be a cleavage product of the yeast nuclein.

Richard Altmann succeeded in 1889 in separating the protein content from the yeast nucleus and isolating an organic acid containing phosphorus. He named it nucleic acid . Kossel and his assistant were able to produce this nucleic acid using Altmann's method and then detect adenine and guanine as cleavage products. It turned out that a carbohydrate also had to be part of the nucleic acid. Kossel chose the collective name nucleobases for the basic substances guanine and adenine as well as their derivatives .

In November 1893 Kossel reported on further discoveries. He and his assistant Albert Neumann had extracted nucleic acid from the calf's thymus glands and treated them with sulfuric acid. A well crystallized cleavage product formed, for which the name thymine was suggested. In 1894 they were able to isolate another substance from the thymus glands. They named it cytosine .

After the structural formulas of guanine and adenine as the purine body and that of thymine as the pyrimidine body had been finally elucidated at the end of the 19th century - mainly through the syntheses of Emil Fischer - Kossel and his colleague Hermann Steudel (1871–1969) were also able to develop the structural formula the nucleobase cytosine as a pyrimidine body can be determined beyond doubt. It had meanwhile been shown that guanine, adenine, thymine and cytosine can be found in all viable cells. The findings about these four nucleobases should lay the foundation for further research. Kossel succeeded in characterizing them as the building blocks of nucleic acids. In his Nobel Lecture on December 12, 1910, he emphasized:

“I managed to get a number of fragments ... which are characterized by a very peculiar collection of nitrogen atoms. There are next to each other ... the cytosine, the thymine, the adenine and the guanine. "

With these findings Kossel created the essential prerequisites for the famous double-helix model of deoxyribonucleic acid, which was developed in 1953 by James D. Watson and Francis Crick . It was later recognized that the sequence of these four bases in the molecular thread of DNA encodes the genetic information. Ulf Lagerkvist about Albrecht Kossel:

"... his elucidation of the chemical nature of some building blocks that make up nucleic acids and chromatine has secured immortality for this exceedingly modest and almost shy man."

The discovery of the fifth primary nucleus base in Marburg in 1900 goes back to Alberto Ascoli . Ascoli's acknowledgment at the end of his publication indicates that Kossel was involved.

Further scientific work

In addition to adenine, Kossel found another, previously unknown, substance in a tea extract. It turned out that the substance was related to theobromine and caffeine. Emil Fischer had adequately characterized both substances. Building on Fischer's findings, Kossel not only set up the empirical formula, but also the structural formula. He suggested the name theophylline for the new substance . Seven years later Emil Fischer succeeded in synthesizing it.

Research into the chemistry of the cell nucleus remained the focus of Kossel's work. As early as 1884 he succeeded in detecting a protein-like body in the nucleus of the goose blood. This confirmed the assumption already expressed in the habilitation thesis that the nucleins consist of a protein body and the phosphorus-containing substance. Kossel suggested the name histone for this protein .

Friedrich Mieschers had found a basic substance in the sperm cells of the salmon, which was connected to the nucleus like salt, and called it protamine . Kossel proved their protein nature. In the protamine of the sperm cells of the sturgeon, which was given the name "Sturin", he discovered a new basic substance, histidine . The discovery took place at the same time as Sven Gustaf Hedin . Kossel proved the already known basic amino acids arginine and lysine. The protamines of salmon (salmin) and herring (clupein) also served as raw materials. Protamines and histones were proteins that contained comparatively fewer amino acids. They formed the subject of various further investigations. Together with his colleague Friedrich Kutscher , Kossel developed a new analysis method for proteins. This so-called silver baryta process remained the best analytical method for many years. It made it possible to quantitatively determine the proportion of the three basic amino acids in various proteins. Kossel's intensive search for a principle of order for the proteins began. He later used flavic acid for the analyzes, which forms an almost insoluble salt with arginine . It turned out that the guanidine part of arginine, the imidazole part of histidine and the terminal amino group in lysine are not involved in the peptide binding of proteins. Kossel suggested that these unbound nitrogenous substructures have a certain biological meaning:

“I imagine the protein molecule in such a way that it can respond to a chemical attack with any of its characteristic groups at any time. Just as the grapes hang on a vine, the protein molecule has a large number of characteristic groups ... If any special combinations are required, they are already there in a vulnerable form. "

Kossel also suspected that the functions of proteins must be derived from their chemical structure.

The building block hypothesis of Kossels, as he put it when he took office as prorector in the auditorium of Heidelberg University, should prove of particular importance for the development and basic understanding of biochemistry: Carbohydrates and proteins often consist of nothing but similar, smaller pieces. As an example, Kossel cited the carbohydrates starch and glycogen, which are formed from the simple substance dextrose. It would be the same with proteins, they are also made up of pieces, the amino acids.

“Some of these pieces or segments, for example leucine, can be repeated many times, but then there are others in between. ... The way of joining together ... is a lawful one. "

"The protein substances that the chickens eat must be rearranged to a certain extent in order to later appear as a new type of protein in the horny structures of the skin or in the blood or in the cartilage."

From the vegetable protein molecules that are supplied to the animal organism, the amino acids arise through digestive processes. The body's own proteins would then be built from these building blocks in the organism. Kossel related this “building block hypothesis” not only to proteins, but also to fats, carbohydrates and nucleic acids.

To prove that the building blocks in all living things are identical, he and his colleagues examined many organisms. Kossel found them in the scales of the Baltic fish, in the Heidelberg glow worms, in the baker's yeast, in Mecklenburg geese and cattle, in butterflies and snapdragons and in Indian tea leaves.

Together with Henry Drysdale Dakin , Kossel discovered the enzyme arginase , which splits arginine into ornithine and urea .

Considerations about the inheritance processes can be found in his Nobel Lecture in December 1910. There he emphasized that the proteins of the cell nucleus that are loosely bound to the nucleic acid have an unusually high proportion of nitrogen-rich amino acids. The high nitrogen content also applies to the nucleic acids themselves and clearly distinguishes both groups from the other components of the cell.

"It is these nitrogen-rich and phosphorus-containing groups of atoms whose deposition sites ... are first set in motion during cell division and whose transfer to other cells makes up an essential part of the fertilization process."

In a speech at the annual celebration of the Heidelberg Academy in 1921, Kossel said:

“… Hereditary factors are transmitted during fertilization and must therefore be deposited in the smallest dimension in the fertilized egg. Today we can hardly imagine any other way of defining so many form and substance-determining systems in a very small space than by relating them to the storage of molecules and atoms. [...] If one thinks of a letter in place of each protein building block, a precise list of the properties of an organism can be provided by a suitable combination of these. ... Besides them we find other substances that can increase the possibilities of combination! "

Kossel's investigations were reflected in 120 publications. Shortly before his death in 1927, Albrecht Kossel presented the level of knowledge in a larger monograph entitled “Protamine and Histone”.

Editor of the journal for physiological chemistry

In 1877 Felix Hoppe-Seyler founded the journal for physiological chemistry for his new subject . Kossel became a member of the editorial board in 1895, which also included biochemists from abroad. When Hoppe-Seyler died in the same year, Eugen Baumann asked Kossel to jointly publish the journal, which was now called Hoppe-Seyler's journal for physiological chemistry . Kossel remained the editor after Baumann's death in 1896. This journal was of particular importance for the development of physiological chemistry. Well-known biochemists from home and abroad were members of the editorial team.

Honors

The meeting center built in 1963 in the Marburg student village was called the Albrecht-Kossel-Haus (now the Max-Kade-Zentrum ) until it was demolished in 2012 . The Albrecht Kossel Prize for Biochemistry has been awarded by the Society of German Chemists since 2014 . The Albrecht Kossel Institute at the University of Rostock is named after him.

literature

Web links

Commons : Albrecht Kossel  - Collection of images, videos and audio files

Individual evidence

  1. ^ Matriculations of Albrecht Kossel in the Rostock matriculation portal
  2. ↑ a b Wolfgang U. Eckart and Christoph Gradmann : Albrecht Kossel , in: Doctors Lexicon. From antiquity to the present , 1st edition CH Beck Munich 1995, p. 219; 2nd edition 2001, p. 188f, 3rd edition Springer Berlin Heidelberg 2006, p. 196f, ISBN 978-3-540-29584-6 (print), ISBN 978-3-540-29585-3 (online) . Medical glossary: ​​Albrecht Kossel doi : 10.1007 / 978-3-540-29585-3 .
  3. ^ Heidelberg University: Heidelberg Nobel Prize Winner , accessed on April 8, 2017.
  4. ^ Albrecht Kossel: To the chemistry of the cell nucleus . In: Zeitschrift für Physiologische Chemie Volume 7, 1882-1883, p. 7.
  5. ↑ J. Piccard: About protamine, guanine and sarkine as components of salmon sperm . In: Reports of the German Chemical Society. 1874, p. 1714.
  6. ↑ Albrecht Kossel: About a new base from the animal body . In: Reports of the German Chemical Society: Issue 18, 1885, p. 79.
  7. ^ Albrecht Kossel: Further contributions to the chemistry of the cell nucleus . In: Journal of Physiological Chemistry . Volume 10, 1886, p. 248.
  8. ↑ Albrecht Kossel: About the chemical composition of the cell . In: Archives for Anatomy and Physiology / Physiological Department . 1891, p. 178.
  9. ^ A. Kossel, A. Neumann: About thymine, a cleavage product of nucleic acid . In: Reports of the German Chemical Society . Volume 26, 1893, p. 2753
  10. ↑ Representation and cleavage products of nucleic acid (adenylic acid). In: Reports of the German Chemical Society . Volume 27, 1894, p. 2215; About nucleic acid and thymic acid . In: Zeitschrift für Physiologische Chemie Volume 22, 1896-1897, p. 74.
  11. ↑ A. Kossel, H. Steudel: Further investigations on cytosine . In: Hoppe-Seyler's journal for physiological chemistry . Volume 38, 1903, p. 49.
  12. ↑ a b A. Kossel: About the chemical composition of the cell nucleus . Nobel Lecture on October 12, 1910 in Stockholm. Munich Medical Weekly Volume 58, 1911, p. 65.
  13. ↑ Ulf Lagerkvist on Albrecht Kossel in: DNA Pioneers and Their Legacy , Yale University Press, New Haven and London, 1998, page 73.
  14. ^ A. Ascoli: About a new cleavage product of yeast nuclein . In: Hoppe-Seyler's journal for physiological chemistry. Volume 31, 1900-01, p. 161.
  15. ↑ A. Kossel: About the theophylline, a new component of thees . In: Journal of Physiological Chemistry. Volume 13, 1889, p. 298.
  16. ↑ A. Kossel: About a pepton-like component of the cell nucleus . In: Journal of Physiological Chemistry. Volume 8, 1884, p. 511.
  17. ↑ A. Kossel: About the basic substances of the cell nucleus . In: Journal of Physiological Chemistry Volume . 22, 1896-1897, p. 176.
  18. ^ A. Kossel, F. Kutscher: Contributions to the knowledge of the protein bodies . In: Hoppe-Seyler's journal for physiological chemistry . Volume 31, 1900, p. 165.
  19. ↑ A. Kossel, RE Gross: About the representation and quantitative determination of arginine. In: Hoppe-Seyler's journal for physiological chemistry. Volume 135, 1924, p. 167.
  20. ↑ S. Edlbacher: Albrecht Kossel in memory , In: Hoppe-Seyler's Journal of Physiological Chemistry. Volume 177, 1927, p. 1.
  21. ↑ A. Kossel: The problems of biochemistry . Rector's speech in Heidelberg on November 24, 1908. J. Horning University Printing House, Heidelberg 1908.
  22. ↑ A. Kossel: About the relationship of biochemistry to the morphological sciences . In: Meeting reports of the Heidelberg Academy of Sciences, mathematical and scientific class. Dept. B 1921, Abh. 1, pages 1–21, Carl Winters Universitäts-Buchhandlung Heidelberg.
  23. ↑ A. Kossel: Protamine and Histone . Volume 2 individual presentations from the field of biochemistry, ed. by S. Edlbacher, 1929.
  24. ^ German Academy of Sciences Leopoldina: Members: Albrecht Kossel. Retrieved December 10, 2019 .
  25. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen Philosophical-Historical Class, follow 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class, follow 3 , Vol. 50), Vandenhoeck u. Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 138.
  26. ↑ Russian Academy of Sciences: Foreign members of the Russian Academy of Sciences since 1724. Retrieved December 11, 2019 (Russian).
personal data
SURNAME Kossel, Albrecht
BRIEF DESCRIPTION German physician and physiologist, Nobel Prize in Physiology or Medicine 1910
DATE OF BIRTH September 16, 1853
PLACE OF BIRTH Rostock
DATE OF DEATH July 5, 1927
Place of death Heidelberg