Total synthesis by modern chemical ligation methods and high resolution (1.1 A) X-ray structure of ribonuclease A

The total chemical synthesis of RNase A using modern chemical ligation methods is described, illustrating the significant advances that have been made in chemical protein synthesis since Gutte and Merrifield's pioneering preparation of RNase A in 1969. The identity of the synthetic product was confirmed through rigorous characterization, including the determination of the X-ray crystal structure to 1.1 Angstrom resolution.