4.2.3. Papain-Like Protease (PLpro)
PLpro is found in all the members of the coronavirus family. It plays a
major role in the release of non-structural proteins from the N terminal
part of the polyproteins 1a and 1ab . It also acts as an antagonist
towards interferon and is seen to inhibit the interferon regulatory
factor 3 activation . This is important as by targeting PLpro, viral
replication can be inhibited and can save the healthy cells from
receiving signaling cascades from the infected cells . Drugs such as
Disulfiram, Lopinavir, and Ritonavir are known clinical protease
inhibitors against MERS and SARS and currently, their effectiveness
towards COVID-19 is being tested in clinical trials .