Choosing to research a little about the history of proteins, the word 'protein' derives from a Greek word protas, which means primary importance. The definition couldn't be more right. Proteins function to sustain life because proteins make tissues, tissues make cells, and cells make organs. They basically do everything in cells.
Gerardus Johannes Mulder, a chemist, was the first to really describe proteins, but was named by his associate Jöns Jakob Berzelius in 1838. While analyzing common proteins, he discovered one similarity: the empirical formula C400H620N100O120P1S1. He concluded that their origin was one big molecule. Finally, Mulder's associate, Berzelius, proposed the word protein to Mulder, helping Mulder's studies expand even further about proteins. Berzelius used it to express his discoveries of large organic compounds.
Proteins were also used for studying about organic compounds, later connecting to the importance of animal nutrition. There was an open ended question with no answer about the concept of "animal substance", which were thought to build body component like muscles, skin, and blood. Not only did this involve animal structures, but humans, as well. The early nutritional scientists believed "protein was the most important nutrient for maintaining the structure of the body, because it was generally believed that "flesh makes flesh". Later in 1926, James B. Sumner showed that enzymes could be isolated and crystallized. Sumner also proved that the enzyme urease (a natural enzyme that catalyzes the hydrolysis of urea into ammonium carbonate) was an enzyme.
There have been several scientists who have succeeded in their predictions based off of one's idea. Linus Pauling predicted a regular protein's secondary structure based on hydrogen bonding, based off of William Astbury's idea in 1933. Walter Kauzman brought denaturation to life about proteins. Denaturation occurs when an enzyme (a protein) or nucleic acid's loses its function. Many factors contribute tot denaturation such as temperature. Because of Astbury, there is now a better understanding to protein folding and structure.
By 1955, a large discovery was made by Sir Federick Sanger who succeeded in completing the amino acid sequence, correctly. Sir Federick Sanger used insulin, as the very first protein to be sequenced out. Sanger demonstrated that all proteins have (certain structures), resulting in the Nobel Prize in 1958. Another protein structure discovery of 1958 includes the first protein structures to be solved were hemoglobin and myoglobin, by Max Perutz and Sir John Cowdery Kendrew. The X-Ray diffraction analysis made that possible and they both got the Nobel Prize in the 1980s.