3.4.2 Helicase
Helicase (nsp13) is a critical multi-functional protein required for
virus replication containing two main domains; N-terminal metal binding
domain (MBD) and a conserved helicase domain at the C-terminus (Hel). In
positive-sense RNA viruses, the enzyme separates nucleic acid and unfold
the highly stable secondary structures within the genomic RNA to
increase the efficiency of its translation (Adedeji et al., 2012a).
Despite the essential function of helicase in virus multiplication, a
few potential inhibitors of nsp13 have been reported so far (Adedeji et
al., 2012b; Shum and Tanner, 2008).
A 1,2,4-triazole derivative, SSYA10-001, has shown inhibition effect on
both helicase of SARS-and MERS-CoVs with EC50 values of 25 μM and 7 μM,
respectively (Adedeji et al., 2014). In another study, Yu et al
demonstrated that myricetin and scutellarein can inhibit the SARS-CoV
helicase protein by affecting the ATPase activity (Yu et al., 2012). The
potent inhibition of the helicase activities and replication of SARS
coronavirus with EC50 of less than 10 μM is also reported by the
Adamantane-derived Bananins (Tanner et al., 2005).