Hugo Theorell

Axel Hugo Theodor Theorell was born on July 6, 1903, in Linköping. Stricken with polio as a young medical student at the Karolinska Institute, which left him with paralyzed legs, he turned his brilliant intellect from clinical medicine to biochemical research.

Working in Berlin with Otto Warburg and later at the Nobel Medical Institute in Stockholm, Theorell accomplished the historic separation of the 'yellow enzyme' into its coenzyme (riboflavin phosphate) and apoenzyme protein components in 1935, demonstrating how vitamins act as cofactors in enzymatic reactions. He was the first to crystallize pure myoglobin and isolated alcohol dehydrogenase, enabling blood alcohol testing. An accomplished concert violinist, he was awarded the 1955 Nobel Prize in Physiology or Medicine.