Insulin is a hormone, part of the central metabolic control system in most animals, which forces the cells to take glucose from the blood and store it as glycogen, as well as to take fatty acids and store them as fat. Although the connection between pancreas and diabetes was known since the 19th century, only in 1922 a group of canadian researches managed to prove that insulin was the substance responsible for this, and developed a procedure to obtain it from fetal calf pancreas with enough purity to use on humans. Until that year, a diagnosis of diabetes mellitus was a 100% death sentence. In 1923, Banting and Macleod received the Nobel Prize for the discovery, which they shared with their coworkers Best and Collip.
This was not the only Nobel Prize to be given to the insulin researchers: in 1958 one was given to Frederick Sanger for determining its primary structure, in 1964 – another one to Dorothy Hodgkin for determining its tertiary structure and another one in 1977 for Rosalyn Yalow for insulin radioimmunoassay (a way to quickly and precisely measure insulin concentration in blood). Not surprising, because currently there are 171 million people or or 2.8% of the world’s population are currently alive with diabetes.
Since 1980, human insulin is produced by genetically modified bacteria, which has since became a routine practice known as protein expression, a cornerstone of biochemical research, which made huge numbers of pure proteins available immediately in virtually unlimited quantities.
Some people (such as the author of Bittersweet) argue that this is not a true victory for science, that the brief invariably lethal ketoacidic shock is replaced with lifelong suffering and numerous complications, but nobody would argue that it would have been best if insulin was never discovered. All it means is that there is still a great incentive to find a complete cure, which will most likely be a way to reactivate the insulin-producing cells (the islets of Langerhans). Who knows, maybe the next insulin Nobel Prize will go to a stem cell researcher?