Wednesday, October 29, 2008

Nobel Laureate: Albrecht Kossel


The Nobel Prize in Physiology or Medicine 1910.
"in recognition of the contributions to our knowledge of cell chemistry made through his work on proteins, including the nucleic substances"

Albrecht Kossel (1853 - 1927) won the Noble Prize for his studies on proteins, especially those proteins that bind to nucleic acids. He was the first to characterize protamines and histones.

The significance of Kossel's work was not fully appreciated because at the time proteins were thought to be the information carrying molecules and nucleic acids were merely structural components of the nucleus. One gets the impression that the simplicity of the protamines, and to a lesser extent, the histones, was a disappointment.

The flavor of thinking in 1910 is captured by the presentation speech on the Nobel rize website.

Nobel Laureates
There are several kinds of proteins. One group which is included here are the so-called protamines obtained from the milt of fish. Kossel has made a detailed study of these. For these a relatively simple structure has been discovered inasmuch as the number of dissimilar atom groups in them is not very great. They therefore present simpler relationships than proteins in general, and consist mainly of substances belonging to the group which I have just called basic breakdown products of protein. For certain protamines Kossel, thanks to his methods of determination, has in fact been able to establish the quantitative relationships of the building blocks making up these protamines, a goal which we seem to be far from attaining where the other proteins are concerned.

Work on these most simple protein bodies, i.e. the protamines, is however not only of great importance because it has explained the structure of such protein bodies. The protamines are also of direct interest for the knowledge of certain cells and their life, because they are in fact characteristic of certain transformation products of the cells and are formed from ordinary protein.

One protein group, first observed by Kossel, consists of the so-called histones. They stand between the protamines and what is termed ordinary protein. This group, again, is important because of its occurrence as a component of certain cells, and has also been studied in detail by Kossel.

Professor Kossel has made an extensive and important study of the problem of the protein compounds in cells. As we have already mentioned, the proteins are very complex bodies. Within the cells the relationships are further complicated by the fact that the proteins there are combined in varying degrees with other substances such as those grouped under the name of «nucleic acids.
It is clear from Kossel's Nobel Lecture that he recognized the importance of chromatin in heredity but was unclear about which component corresponded to genes.
If we now summarize the results of the investigations of loosely bound nuclein substances, the result is a follows: A composition of the chromatin substance of the cell nucleus from two components, the one rich in bound phosphoric acid and having the qualities of an acid; the second showing a protein with the qualities of a base. In their chemical structure both components show a notable similarity based on the remarkable accumulation of nitrogen atoms and because of this chemical structure the chromatin formations can be sharply differentiated from the remaining cell components; and this quality must obviously be associated with the function of the chromatin substances. These atom groups rich in nitrogen and containing phosphorus are those whose deposits in the chromosomes are first set in motion during cell division and whose transmission to other cells forms an essential part of the reproductive process.

No comments :

Post a Comment