Solid Phase Synthesis of a 42-Residue Fragment of Staphylococcal Nuclease: Properties of a Semisynthetic Enzyme

After discovering an error in their original primary sequence analysis of staphylococcal nuclease, in which residue 43 was misidentified as glutamine instead of glutamic acid, Ontjes and Anfinsen published this paper. They reported that a resynthesis of the correct sequence in turn yielded a product with high biological activity. Therefore, they concluded that residue 43, although not essential for folding, was very important for catalytic activity once folding had occurred.