Anfinsen, Christian Boehmer (1916-1995), an American biochemist, shared the 1972 Nobel Prize in chemistry with fellow American scientists Stanford Moore and William H. Stein. This group shared the prize for research into the fundamental chemistry of enzymes (natural substances that speed up chemical reactions in all living things). All three scientists worked with an enzyme called ribonuclease. Anfinsen won half of the prize for his discovery of the relationship between the structure and function of ribonuclease. See Enzyme.