Christian Boehmer Anfinsen was an American biochemist who won the Nobel Prize for his pioneering work on the structure of enzymes and the relationship between enzyme functions and the amino acid sequence. He shared the prize with two other American scientists, William Howard Stein and Stanford Moore. From his experiments on the ‘ribonuclease’ enzyme he came to the conclusion that the information regarding the tertiary structure of the enzyme is contained in the sequential structure of the amino acids present along the protein chain. His work led to the understanding of the causes of many diseases such as Alzheimer’s disease, mad cow disease, cystic fibrosis, genetic emphysema and many types of cancers. His early work with Steinberg was on the non-uniform labeling of newly synthesized proteins which later helped Canfield and Dintzis to determine that proteins are sequentially synthesized from amino acids ‘in vivo’ and to find out the rate of polymerization of amino acids. In the mid-1950s Anfinsen concentrated on the structure and function of enzymes which helped him suggest the ‘thermodynamic hypothesis’ related to the refolding of many proteins to their native forms even after the cleavage of the disulphide bonds which disrupted the tertiary structure.