City researchers find COVID-19 candidates

Shanghai scientists say they have discovered an attractive drug target for COVID-19.

After the novel coronavirus enters human cells, it will immediately make use of what is in the cells to produce pp1a and pp1ab, two polyproteins which are necessary for the virus to replicate and develop into a full-body invasion.

However, pp1a and pp1ab just provide the raw material. They need to be cut into several parts, which are then rearranged and reassembled as a complicated mechanism for virus replication.

The cutting is done by Mpro, a key enzyme known as “magic scissors.” Thus Mpro is an attractive target for treatment.

Researchers from ShanghaiTech University and Shanghai Institute of Materia Medica under Chinese Academy of Sciences first determined the high-resolution crystal structure of Mpro. Later, they discovered a powerful Mpro inhibitor called N3. 

Researchers also searched more than 10,000 existing drugs and biologically active natural products, and found some candidates to fight COVID-19. They included disulfiram, carmofur, ebselen and shikonin.

Notably, tests showed ebselen is as effective as N3 in constraining virus replication.

The research was published by scientific journal Nature on Thursday.