Identification and biochemical characterization of halisulfate 3 and suvanine as novel inhibitors of hepatitis C virus NS3 helicase from a marine sponge.
Hepatitis C virus (HCV) is an important etiological agent that is responsible for the development of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV nonstructural protein 3 (NS3) helicase is a possible target for novel drug development due to its essential role in viral replication. In this study, we identified halisulfate 3 (hal3) and suvanine as novel NS3 helicase inhibitors, with IC50 values of 4 and 3 µM, respectively, from a marine sponge by screening extracts of marine organisms. Both hal3 and suvanine inhibited the ATPase, RNA binding, and serine protease activities of NS3 helicase with IC50 values of 8, 8, and 14 µM, and 7, 3, and 34 µM, respectively. However, the dengue virus (DENV) NS3 helicase, which shares a catalytic core (consisting mainly of ATPase and RNA binding sites) with HCV NS3 helicase, was not inhibited by hal3 and suvanine, even at concentrations of 100 µM. Therefore, we conclude that hal3 and suvanine specifically inhibit HCV NS3 helicase via an interaction with an allosteric site in NS3 rather than binding to the catalytic core. This led to the inhibition of all NS3 activities, presumably by inducing conformational changes.
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan. atsushi.5961@ruri.waseda.jp.
Atsushi
A
Furuta
Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan. salam_bio26@yahoo.com.
Kazi Abdus
KA
Salam
Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan. damz_98@yahoo.com.
Idam
I
Hermawan
Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan. akimitsu@ric.u-tokyo.ac.jp.
Nobuyoshi
N
Akimitsu
Department of Chemistry, Biology and Marine Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan. jtanaka@sci.u-ryukyu.ac.jp.
Junichi
J
Tanaka
Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan. h.tani@aist.go.jp.
Hidenori
H
Tani
Department of Microbiology, Division of Medicine, Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan. atsuyay@yamanashi.ac.jp.
Atsuya
A
Yamashita
Department of Microbiology, Division of Medicine, Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan. kmoriishi@yamanashi.ac.jp.
Kohji
K
Moriishi
Institute of Medical Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan. mnakako@hoshi.ac.jp.
Masamichi
M
Nakakoshi
Institute of Medical Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan. tsubuki@hoshi.ac.jp.
Masayoshi
M
Tsubuki
Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Center for Translational Medicine, 14 Medical Drive, #15-02, Level 15, Singapore 117599, Singapore. micpwp@nus.edu.sg.
Poh Wee
PW
Peng
Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Center for Translational Medicine, 14 Medical Drive, #15-02, Level 15, Singapore 117599, Singapore. micys@nus.edu.sg.
Youichi
Y
Suzuki
Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Center for Translational Medicine, 14 Medical Drive, #15-02, Level 15, Singapore 117599, Singapore. naoki_yamamoto@nuhs.edu.sg.
Naoki
N
Yamamoto
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan. y.sekiguchi@aist.go.jp.
Yuji
Y
Sekiguchi
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan. stsuneda@waseda.jp.
Satoshi
S
Tsuneda
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan. noda-naohiro@aist.go.jp.
Naohiro
N
Noda
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004583:Electrons; D016174:Hepacivirus / Q000201:enzymology*; D009281:Naphthalenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D011161:Porifera / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism; D057057:Serine Proteases / Q000737:chemistry; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D054830:Sesterterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D013463:Sulfuric Acid Esters / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors*; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate; D009281:Naphthalenes; D012367:RNA, Viral; D057057:Serine Proteases; D015842:Serine Proteinase Inhibitors; D054830:Sesterterpenes; D013463:Sulfuric Acid Esters; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C000590754:halisulfate 3; C582927:suvanine