Assaying In Vitro Refolding of RNases by Mass Spectrometry

Although evidence has been mounting since the 1930s that proteins could be reversibly denatured, it was not until the 1960s that the elegant experiments of Anfinsen on bovine pancreatic Ribonuclease A (RNase A) established that all the information needed for a protein to acquire three-dimentional structure is contained in its aminoacid sequence (1 ). However, the code that yields a fully folded protein from a string of amino acids has not been deciphered yet.