Albrecht Kossel | Biography

Albrecht Kossel was one of the earliest scientists to apply the exact methods of organic chemistry to problems in the chemistry of living tissue. His investigations into the cell substance nuclein revealed that it contained both protein and nonprotein (nucleic acid) parts. His research into protein components led to the discovery of the amino acid histidine. For his work on cell chemistry and proteins, Kossel won the Nobel Prize for physiology or medicine in 1910.

Karl Martin Leonhard Albrecht Kossel was born on September 16, 1853, in Rostock, Germany. He was the eldest son of a merchant father, also named Albrecht Kossel, and Clara Jeppe Kossel. Botany was Kossel's first love, but his father saw no future in that, so in 1872 Kossel entered the University of Strasbourg to study medicine instead. While there, he came under the influence of Ernst Felix Immanuel Hoppe-Seyler, one of the forefathers of the then-emerging field of biochemistry. In 1877, Kossel passed the state medical exam and began working as an assistant at Hoppe-Seyler's institute of physical chemistry, also in Strasbourg. Kossel received his doctor of medicine degree the following year.

Kossel remained an assistant in Hoppe-Seyler's laboratory until 1881, when he qualified as a lecturer in physiological chemistry. Two years later, he was appointed director of the chemical division at the Berlin physiological institute by another leading German scientist, Emil Heinrich Du Bois-Reymond. From 1887 to 1895, Kossel was a professor at the University of Berlin.

Beginning in 1879 and continuing for many years, Kossel undertook what proved to be trailblazing research on the makeup of the cell substance nuclein. This substance had been discovered a decade before by another of Hoppe-Seyler's star pupils, Johann Frederick Miescher. However, nuclein was still a vague entity when Kossel first set about defining its composition.

Kossel soon determined that nuclein was made up of two parts, one protein and one not. Thus, the word nuclein was eventually replaced by the more specific term nucleoprotein, and the nonprotein portion came to be called nucleic acid. Nucleic acids differed from any other natural products that were known up to that point. When broken down, they produced carbohydrates and nitrogen-bearing compounds called purines and pyrimidines. Kossel further isolated two purines (adenine and guanine), as well as three pyrimidines (thymine, cytosine, and uracil). In addition, Kossel correctly concluded that the function of nuclein was somehow tied in to the formation of flesh tissue. Kossel's writings foreshadowed many important later developments, including modern investigations of nucleic acids as the storers and transmitters of genetic data.

In 1895, Kossel left Berlin for the University of Marburg, where he was a professor and director of the physiological institute. That same year, he began work that lasted for more than three decades as editor of the Zeitschrift für physiologische Chemie, a noted journal founded by Hoppe-Seyler that was for a time the only periodical in the world devoted exclusively to biochemistry. It was primarily in this journal that Kossel's own papers appeared. Then in 1901, Kossel moved again--this time to the University of Heidelberg, where he remained a professor and administrator until his retirement in 1924. Thereafter, Kossel held the post of director of that city's institute for protein investigation.

Starting in the 1890s, Kossel's attention turned more and more to research on proteins. In particular, he studied the proteins in fish sperm cells, which proved simpler than those in other cells. He developed an elaborate theory to explain how complex ordinary proteins could be built from the simple bases present in spermatozoa. Unfortunately, his elegant explanation proved wrong. It was decades before anyone realized that the crucial compounds for this purpose are not the proteins but the nucleic acids, which are present in spermatozoa in their full complexity.

Given the technical limitations of his time, Kossel was remarkably successful at elucidating the makeup of proteins. He discovered histidine, an amino acid that is the chief component of protein. He also devised a method for comparing the amino acids in the sperm of different fish species. In the laboratory, Kossel was never satisfied with purely chemical findings; he always strove to understand the biological meaning of his discoveries. In this regard, Kossele was a pathfinder.

Based on such achievements, Kossel received many honors in addition to the 1910 Nobel Prize. Notable among these were honorary degrees from universities in Cambridge, England; Edinburgh, Scotland; Dublin, Ireland; Ghent, Belgium; and Greifswald, Germany. He was also a member of various societies, including the Royal Society of Sciences in Sweden. Among Kossel's students over the years were several who achieved later prominence, including Phoebus Aaron Theodor Levene, who in 1909 became the first chemist to show that nucleic acids contain a sugar (ribose). Twenty years later, Levene demonstrated that other nucleic acids contain a different sugar (deoxyribose), thus defining the two types of nucleic acid: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).

Kossel married Luise Holtzmann in 1886. They had two children: a daughter, Gertrude, and a son, Walther. The latter, born in 1888, went on to become a distinguished physicist. Kossel died in Heidelberg, Germany at age 73, after a brief illness.