Semisynthesis of Human Ribonuclease-S

Since its conception, the ribonuclease S complex (RNase S) has led to historic discoveries in protein chemistry, enzymology, and related fields. Derived by the proteolytic cleavage of a single peptide bond in bovine pancreatic ribonuclease (RNase A), RNase S serves as a convenient and reliable model system for incorporating unlimited functionality into an enzyme. Applications of the RNase S system in biomedicine and biotechnology have, however, been hindered by two shortcomings: (1) the bovine-derived enzyme could elicit an immune response in humans, and (2) the complex is susceptible to dissociation. Here, we have addressed both limitations in the first semisynthesis of an RNase S conjugate derived from human pancreatic ribonuclease and stabilized by a covalent interfragment cross-link. We anticipate that this strategy will enable unprecedented applications of the RNase-S system.

Automated summary

The ribonuclease S complex has led to historic discoveries in protein chemistry and enzymology, but its applications have been hindered by two main drawbacks: immune response in humans and susceptibility to dissociation. By semi-synthesizing an RNase S conjugate derived from human pancreatic ribonuclease and stabilized with a covalent interfragment cross-link, these limitations have been addressed, enabling unprecedented applications of the RNase-S system.