TY - JOUR
T1 - Inhibition of hepatitis C virus NS3 helicase by manoalide
AU - Salam, Kazi Abdus
AU - Furuta, Atsushi
AU - Noda, Naohiro
AU - Tsuneda, Satoshi
AU - Sekiguchi, Yuji
AU - Yamashita, Atsuya
AU - Moriishi, Kohji
AU - Nakakoshi, Masamichi
AU - Tsubuki, Masayoshi
AU - Tani, Hidenori
AU - Tanaka, Junichi
AU - Akimitsu, Nobuyoshi
PY - 2012/4/27
Y1 - 2012/4/27
N2 - The hepatitis C virus (HCV) causes one of the most prevalent chronic infectious diseases in the world, hepatitis C, which ultimately develops into liver cancer through cirrhosis. The NS3 protein of HCV possesses nucleoside triphosphatase (NTPase) and RNA helicase activities. As both activities are essential for viral replication, NS3 is proposed as an ideal target for antiviral drug development. In this study, we identified manoalide (1) from marine sponge extracts as an RNA helicase inhibitor using a high-throughput screening photoinduced electron transfer (PET) system that we previously developed. Compound 1 inhibits the RNA helicase and ATPase activities of NS3 in a dose-dependent manner, with IC50 values of 15 and 70 μM, respectively. Biochemical kinetic analysis demonstrated that 1 does not affect the apparent Km value (0.31 mM) of NS3 ATPase activity, suggesting that 1 acts as a noncompetitive inhibitor. The binding of NS3 to single-stranded RNA was inhibited by 1. Manoalide (1) also has the ability to inhibit the ATPase activity of human DHX36/RHAU, a putative RNA helicase. Taken together, we conclude that 1 inhibits the ATPase, RNA binding, and helicase activities of NS3 by targeting the helicase core domain conserved in both HCV NS3 and DHX36/RHAU.
AB - The hepatitis C virus (HCV) causes one of the most prevalent chronic infectious diseases in the world, hepatitis C, which ultimately develops into liver cancer through cirrhosis. The NS3 protein of HCV possesses nucleoside triphosphatase (NTPase) and RNA helicase activities. As both activities are essential for viral replication, NS3 is proposed as an ideal target for antiviral drug development. In this study, we identified manoalide (1) from marine sponge extracts as an RNA helicase inhibitor using a high-throughput screening photoinduced electron transfer (PET) system that we previously developed. Compound 1 inhibits the RNA helicase and ATPase activities of NS3 in a dose-dependent manner, with IC50 values of 15 and 70 μM, respectively. Biochemical kinetic analysis demonstrated that 1 does not affect the apparent Km value (0.31 mM) of NS3 ATPase activity, suggesting that 1 acts as a noncompetitive inhibitor. The binding of NS3 to single-stranded RNA was inhibited by 1. Manoalide (1) also has the ability to inhibit the ATPase activity of human DHX36/RHAU, a putative RNA helicase. Taken together, we conclude that 1 inhibits the ATPase, RNA binding, and helicase activities of NS3 by targeting the helicase core domain conserved in both HCV NS3 and DHX36/RHAU.
UR - http://www.scopus.com/inward/record.url?scp=84860329960&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84860329960&partnerID=8YFLogxK
U2 - 10.1021/np200883s
DO - 10.1021/np200883s
M3 - Article
C2 - 22394195
AN - SCOPUS:84860329960
SN - 0163-3864
VL - 75
SP - 650
EP - 654
JO - Journal of Natural Products
JF - Journal of Natural Products
IS - 4
ER -
