Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
J Infect Dis. 2011 Aug 15;204(4):609-16. doi: 10.1093/infdis/jir303.
Hepatitis C virus (HCV) chronically infects >170 million persons worldwide and is a leading cause of cirrhosis and hepatocellular carcinoma. The identification of more effective and better-tolerated agents for treating HCV is a high priority. We have reported elsewhere the discovery of the anti-HCV compound ceestatin using a high-throughput screen of a small molecule library.
To identify host or viral protein targets in an unbiased fashion, we performed affinity chromatography, using tandem liquid chromatography/mass spectrometry to identify specific potential targets. RESULTS. Ceestatin binds to 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) synthase and irreversibly inhibits HMG-CoA synthase in a dose-dependent manner. Ceestatin's anti-HCV effects are reversed by addition of HMG-CoA, mevalonic acid, or geranylgeraniol. Treatment with small interfering RNA against HMG-CoA synthase led to a substantial reduction in HCV replication, further validating HMG-CoA synthase as an enzyme essential for HCV replication.
Ceestatin therefore exerts its anti-HCV effects through inhibition of HMG-CoA synthase. It may prove useful as an antiviral agent, as a probe to study HCV replication, and as a cholesterol-lowering agent. The logical stepwise process employed to discover the mechanism of action of ceestatin can serve as a general experimental strategy to uncover the targets on which novel uncharacterized anti-HCV compounds act.
丙型肝炎病毒（HCV）在全球范围内慢性感染超过 1.7 亿人，是肝硬化和肝细胞癌的主要原因。寻找更有效和耐受性更好的 HCV 治疗药物是当务之急。我们曾在其他地方报道过使用高通量筛选小分子文库发现抗 HCV 化合物 ceestatin。
为了以无偏倚的方式鉴定宿主或病毒蛋白靶标，我们进行了亲和层析实验，并使用串联液相色谱/质谱联用技术来鉴定特定的潜在靶标。
Ceestatin 与 3-羟-3-甲基戊二酰辅酶 A（HMG-CoA）合酶结合，并以剂量依赖的方式不可逆地抑制 HMG-CoA 合酶。Ceestatin 的抗 HCV 作用可通过添加 HMG-CoA、甲羟戊酸或香叶基香叶基焦磷酸逆转。用 HMG-CoA 合酶的小干扰 RNA 处理导致 HCV 复制显著减少，进一步证实 HMG-CoA 合酶是 HCV 复制所必需的酶。
因此，Ceestatin 通过抑制 HMG-CoA 合酶发挥其抗 HCV 作用。它可能作为一种抗病毒药物、研究 HCV 复制的探针以及降低胆固醇的药物而具有应用价值。发现 ceestatin 作用机制所采用的合乎逻辑的逐步过程，可以作为揭示新型未表征抗 HCV 化合物作用靶标的一般实验策略。
