Carl Niemann
Encyclopedia
Carl George Niemann was an American biochemist who worked extensively on the chemistry and structure of proteins, publishing over 260 research papers. He is known, with Max Bergmann
Max Bergmann
Max Bergmann was a Jewish-German biochemist. He was the first to use the Carboxybenzyl protecting group for the synthesis of oligopeptides.-Life and work:Bergmann was born in Fürth, Bavaria, Germany on February 12, 1886....

, for proposing the Bergmann-Niemann hypothesis that proteins consist of 288 residue polypeptides or multiples thereof with periodic sequences of amino acids, and for contributing to the downfall of the cyclol
Cyclol
The cyclol hypothesis is the first structural model of a folded, globular protein. It was developed by Dorothy Wrinch in the late 1930s, and was based on three assumptions. Firstly, the hypothesis assumes that two peptide groups can be crosslinked by a cyclol reaction ; these crosslinks are...

 model of protein structure.

Niemann was born in St. Louis and attended the University of Wisconsin–Madison
University of Wisconsin–Madison
The University of Wisconsin–Madison is a public research university located in Madison, Wisconsin, United States. Founded in 1848, UW–Madison is the flagship campus of the University of Wisconsin System. It became a land-grant institution in 1866...

. After completing his Ph.D. in biochemistry there in 1934 and staying on as research associate until 1935, Niemann took a position at the Rockefeller Institute for Medical Research, where he worked with the eminent protein chemist Max Bergmann
Max Bergmann
Max Bergmann was a Jewish-German biochemist. He was the first to use the Carboxybenzyl protecting group for the synthesis of oligopeptides.-Life and work:Bergmann was born in Fürth, Bavaria, Germany on February 12, 1886....

. Niemann analyzed the amino acid content of range of proteins. Based on Niemann's tests and other published protein analyses, Bergann and Niemann deduced that the sizes of protein molecules are always multiples of 288 and could be expressed according to the formula 2n X 3m. They also suggested that in the polypeptides of a given protein, amino acids occurred in a regular, repeating pattern; for example, they proposed that silk fibroin, known to consist mainly of glycine
Glycine
Glycine is an organic compound with the formula NH2CH2COOH. Having a hydrogen substituent as its 'side chain', glycine is the smallest of the 20 amino acids commonly found in proteins. Its codons are GGU, GGC, GGA, GGG cf. the genetic code.Glycine is a colourless, sweet-tasting crystalline solid...

 and alanine
Alanine
Alanine is an α-amino acid with the chemical formula CH3CHCOOH. The L-isomer is one of the 20 amino acids encoded by the genetic code. Its codons are GCU, GCC, GCA, and GCG. It is classified as a nonpolar amino acid...

, had a sequence of glycine-alanine-glycine-[other], with the glycine/alanine pattern making up three of every four amino acids and other residues falling periodically into the fourth spot. Niemann worked with Bergann on this theory from 1936–1938; by 1939, they came to reject the theory as other biochemists provided evidence contradicting their proposed formula.

After his work at the Rockefeller Institute and at the University College Hospital
University College Hospital
University College Hospital is a teaching hospital located in London, United Kingdom. It is part of the University College London Hospitals NHS Foundation Trust and is closely associated with University College London ....

 as a Rockefeller Foundation Fellow, and with strong support from Warren Weaver
Warren Weaver
Warren Weaver was an American scientist, mathematician, and science administrator...

, Niemann joined Linus Pauling
Linus Pauling
Linus Carl Pauling was an American chemist, biochemist, peace activist, author, and educator. He was one of the most influential chemists in history and ranks among the most important scientists of the 20th century...

's Crellin Laboratory at Caltech in 1938. In 1939, Niemann and Linus Pauling
Linus Pauling
Linus Carl Pauling was an American chemist, biochemist, peace activist, author, and educator. He was one of the most influential chemists in history and ranks among the most important scientists of the 20th century...

 published a strong critique of Dorothy Wrinch's cyclol
Cyclol
The cyclol hypothesis is the first structural model of a folded, globular protein. It was developed by Dorothy Wrinch in the late 1930s, and was based on three assumptions. Firstly, the hypothesis assumes that two peptide groups can be crosslinked by a cyclol reaction ; these crosslinks are...

 hypothesis of protein structure, which held that globular protein
Globular protein
Globular proteins, or spheroproteins are one of the two main protein classes, comprising "globe"-like proteins that are more or less soluble in aqueous solutions...

s formed inter-linked, cage-like polyhedral
Dihedral group
In mathematics, a dihedral group is the group of symmetries of a regular polygon, including both rotations and reflections. Dihedral groups are among the simplest examples of finite groups, and they play an important role in group theory, geometry, and chemistry.See also: Dihedral symmetry in three...

 structures. Niemann and Pauling argued that X-ray crystallography
X-ray crystallography
X-ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and causes the beam of light to spread into many specific directions. From the angles and intensities of these diffracted beams, a crystallographer can produce a...

 and other data indicated that cyclol bonds did not occur in proteins and that polypeptides were held together in globular proteins by hydrogen bond
Hydrogen bond
A hydrogen bond is the attractive interaction of a hydrogen atom with an electronegative atom, such as nitrogen, oxygen or fluorine, that comes from another molecule or chemical group. The hydrogen must be covalently bonded to another electronegative atom to create the bond...

s and weaker intermolecular force
Intermolecular force
Intermolecular forces are forces of attraction or repulsion which act between neighboring particles: atoms, molecules or ions. They are weak compared to the intramolecular forces, the forces which keep a molecule together...

s. He went on to head research in immunochemistry
Immunochemistry
Immunochemistry is a branch of chemistry that involves the study of the reactions and components on the immune system.Various methods in immunochemistry have been developed and refined, and been used in scientific study, from virology to molecular evolution....

 and the organic chemistry
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...

 of proteins.

In 1945, Niemann became of full professor at Caltech. He was elected to the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...

 in 1952, and was also elected to the American Academy of Arts and Sciences
American Academy of Arts and Sciences
The American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...

 and the New York Academy of Sciences
New York Academy of Sciences
The New York Academy of Sciences is the third oldest scientific society in the United States. An independent, non-profit organization with more than members in 140 countries, the Academy’s mission is to advance understanding of science and technology...

. He died of a heart attack, according to his eulogizer John D. Roberts
John D. Roberts
John Dombrowski Roberts is an American chemist. He has made contributions to the integration of physical chemistry, spectroscopy and organic chemistry for the understanding of chemical reaction rates....

, "at the very height of his career".

Further reading

  • "Niemann, Carl G. (1908-1964)". Biographical Memoirs, Vol. 40. National Academy of Sciences, 1969.
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