William Rose: The great American Pioneer Unveiled 20 Amino Acids for Optimal Nutrition.

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William Rose

Introduction

William Cumming Rose. The American scientist and researcher in the field of nutrition. William Rose was profound professor of Biochemistry.   L-Threonine, abbreviated Thr, is the last common amino acid to be discovered by him which is milestone in the field of human nutrition.He was born in Greenville, South Carolina. Rose graduated with a B.S. from Davidson College in 1907. He received a Ph.D. in 1911 from Yale University, where he worked under the direction of L. B. Mendel. 

During 1913 he studied under Franz Knoop at Freiburg, Germany.  Rose then taught at the universities of Pennsylvania and Texas and in 1922 went to the University of Illinois, where he served as professor of biochemistry and head of the biochemistry division of the chemistry department until 1953 and as research professor of biochemistry from 1953 until his retirement in 1955. He was elected to the National Academy of Sciences in 1936 and was awarded a 1966 National Medal of Science.

William Rose

Notable research endeavors and discoveries

William Rose‘s  research interests centered mainly on the dietary role and biosynthesis of amino acids. In 1914 T. B. Osborne and L. B. Mendel demonstrated that tryptophan and lysine are indispensable components of food, at least for the growing rat. Several years later, independent investigations by H. Ackroyd and F. G. Hopkins and by Rose and G. J. Cox proved that histidine also must be included in the food of animals. Thus, unequivocal proof was offered that certain amino acids cannot be synthesized by living cells out of materials ordinarily present and consequently must be supplied preformed.

By 1930, when Rose’s investigation began, not one of the remaining 16 amino acids then known had been classified with respect to its nutritive importance. Biochemical literature contained the results of several such experiments, in which the animals declined in weight and rejected the food. In endeavoring to explain this behavior, the investigators usually assumed that the loss of appetite was due to the taste of the amino acids. Despite these discouraging results, Rose decided to undertake studies of this kind and to include all known amino acids in the food.

 

L- Threonine

The first amino acid mixture was formulated to imitate as closely as possible the composition of casein of milk. The results of the feeding trials were quite similar to those reported from other laboratories. The young rats lost weight very rapidly at first and thereafter decline slowly until death resulted. 

To ac- count for these effects, Rose postulated that proteins contain at least one indispensable component other than the amino acids then recognized. Proceeding on this hypothesis, Rose hydrolyzed the proteins and fractionated the resulting mixture of amino acids by a variety of chemical techniques.

L-Threonine, abbreviated Thr, is the last common amino acid to be discovered. Although biochemist William Rose and colleagues at the University of Illinois (Urbana–Champaign) are usually credited with discovering Thr in 1936, biochemist Samuel B. Schryver and botanist H. W.

Contributions to Protein Nutrition

The discovery of threonine added a fourth amino acid to the group of indispensable dietary constituents. Further- more, it provided a technique for establishing the nutritive significance of the other amino acids by omitting them from the food one at a time. Making use of this device, Rose promptly classified the remaining components of proteins. As is now generally known, the results demonstrated that for the young rat 10 of the amino acids ordinarily found in proteins are necessary for maximal gains in weight. The others can be synthesized in the animal of simpler compounds and consequently need not be included in the food.

In-depth exploration of Rose's work in protein metabolism

William Rose discovered and structurally characterized the amino acid threonine and showed that is “essential”, i.e., not manufactured by the body, and must be obtained from the diet.  He showed that different amino acids are essential to different organisms; studied creatine and creatinine metabolism, endogenous purine metabolism, neophropathic effects of dicarboxylic acids and their derivatives, and nutrititive properties of amino acids; investigated the role of proteins in metabolism, the metabolic interrelationships between amino acids. He also determination of the amino acid requirements of human subjects; showed that histidine, which is an essential amino acid for all animals tested so far, is not essential for man.

Significance of his findings in understanding dietary protein requirements

The essentials for this species are valine, leucine, isoleucine, threonine, methionine, phenylalanine, tryptophan, lysine, histidine, and arginine. The exclusion of any one of these, with the exception of arginine, leads to profound nutritive failure, diminished appetite, and eventual death. In contrast to such spectacular effects, depriving a growing rat of arginine merely decreases the rate of gain. 

This is because arginine can be synthesized by the rat, but not at a speed in keeping with the requirements of the organism for optimal growth. The classification of arginine as essential or nonessential is purely a matter of definition. Rose defined an essential dietary component as one which cannot be synthesized by the species in question qut of materials ordinarily available to the cells at a speed which is commensurate with the needs for optimal growth.

William Rose's Influence on Human Nutrition

Odds are overwhelmingly against the possibility of an amino acid deficiency in a subject who is consuming twice the highest observed minimal requirement. Because of this fact, William Rose chose to designate these double minimal values as “safe” intakes. Tyrosine and cystine are capable of exerting pronounced sparing effects upon the minimal needs of human subjects for phenylalanine and methionine, respectively. The cystine effect is particularly important, since methionine appears to be the limiting amino acid in the diets consumed in many areas of the world.

Numerous experiments were conducted in animals by Rose and his associates to ascertain whether the indispensable amino acids may be replaced in the diet by compounds more or less closely related to them in chemical structure. In such experiments the growth of a young mammal becomes an “indicator” of a chemical reaction in just as real a sense as a color change may denote the complexion of the neutralization of an acid by an alkali. Space does not permit a detailed consideration of the findings obtained in these experiments, but this technique affords a method whereby one may determine the extent to which certain types of reactions may be accomplished by living organisms.

Legacy in shaping dietary guidelines and nutritional recommendation.

These were amino acids, corn starch, sucrose, butterfat (which had been melted and centrifuged to remove particles of protein), corn oil, inorganic salts, and an appropriate mixture of vitamins. The amino acid mixtures, composed initially of the 10 acids previously found to be necessary for the growing rat, were consumed in aqueous solution flavored to taste with sucrose and filtered lemon juice. The vitamins were taken each day in the form of pills. The other components listed above and a baking powder made in the laboratory were mixed with water, rolled into thin layers, and baked into wafers.

Honors and Recognition

Over the course of William Rose career he published 124 research, biographical, and review articles. William Rose was honored many times for his achievements, being elected to the National Academy of Sciences in 1936 and receiving the National Medal of Science in 1966.

Reference: The Discovery of the Amino Acid Threonine: the Work of William C. Rose – Journal of Biological Chemistry (jbc.org)

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