Kossel, Albrecht

Ionic bonding was proposed by the German physicist Walther Kossel in 1916 in or der to explain the ability of substances such as molten sodium chloride to conduct an electric current He was the son of Albrecht Kossel winner of the 1910 Nobel Prize in physiology or medi cine for early studies in nu cleic acids... 

Histones are small, basic proteins required to condense DNA into chromatin. They have been first described and named in 1884 by Albrecht Kossel. There are five main histones HI, H2A, H2B, H3 andH4. An octamer of core histones H2A, H2B, H3 andH4 is located inside a nucleosome, the central building block of chromatin, with about 150 base pairs of DNA wrapped around. The basic nature of histones, mediated by the high content of lysine and arginine residues, allows a direct interaction with the acidic phosphate back bone of DNA. The fifth histone HI is located outside at the junction between nucleosomes and is referred to as the linker histone. Besides the main histones, so-called histone variants are known, which replace core histones in certain locations like centromers. 

Cytosine and thymine were first isolated by hydrolysis of calf thymus tissue by Albrecht Kossel (1853-1927) and A. Neumann during 1893-1894. Thymine s structure was published in 1900 and confirmed over the next several years when it was synthesized by several investigators. In 1903, cytosine was synthesized by Henry Lord Wheeler (1867-1914) and Treat B. Johnson, confirming its structure. Uracil was first isolated in 1900 from yeast nucleic acid found in bovine thymus and herring sperm. The methylation of uracil produces thymine thymine is also called 5-methyluracil because methylation takes place at the fifth carbon in uracil to produce thymine. 

Albrecht Kossel Ph y siology / Med icine Isolation of nucleic acid bases... 

Kossel, Ludwig Karl Martin Leonhard Albrecht 155... 

German Chemist Ludwig Karl Martin Leonhard Albrecht Kossel was born in Rostock on September 16, 1853, the eldest son of Albrecht Kossel, the merchant and Prussian consul, and his wife Clara Jeppe. He attended the secondary school in Rostock and went to the newly founded University of Strass-burg in 1872 to study medicine. He received his doctorate of medicine in 1878. 

Kossel had honorary doctorates from the Universities of Cambridge, Dublin, Ghent, Greifswald, St. Andrews, and Edinburgh, and he was a member of various scientific societies, including the Royal Swedish Academy of Sciences and the Royal Society of Sciences of Uppsala. Albrecht Kossel died on July 5, 1927. 

Ber., 1885, xviii, 79 Z. physiol. Chem. 1886, x, 248. Albrecht Kossel (Rostock, 16 September 1853-Heidelberg, 5 July 1927) studied in Strasbourg under Hoppe-Seyler, professor of physiology in Berlin, Marburg (1895) and Heidelberg (1901-23). Nobel Laureate 1910. 

Kossel, Karl Martin Leonhard Albrecht (1853-1927) German chemist noted for his discovery of adenine, cytosine, thymine, and uracil as breakdown products of nucleic acids. He also discovered histone and histidine. He was awarded the Nobel Prize for physiology or medicine in 1910 in recognition of his work on cell chemistry. 

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