El-Fakharany E M, Haroun B M, Ng T B, Redwan E R
Antibody laboratory, Protein Research Department, Genetic Engineering and Biotechnology Research Institute, MubarakCity for Scientific Research and Technology Applications, New Borg EL-Arab post-code 21394, Alexandria.
Protein Pept Lett. 2010 Aug;17(8):1031-9. doi: 10.2174/092986610791498948.
There is no protective vaccine or effective drug against hepatitis C virus (HCV). Sustained virological response to INF/ribavirin treatment regimen has an efficiency of about 50%. Many patients worldwide have used traditional medicines and herbal medicine in particular. A laccase has been purified from oyster mushroom (Pleurotus ostreatus) to homogeneity by DEAE Affi-gel blue gel, CM-Sephadex G-50 and Sephadex G-100. The molecular weight of the laccase was about 58 kDa in SDS-PAGE. The optimum pH and temperature of the laccase activity were pH 4.0 and 60 degrees C, respectively. The activity of the enzyme increased steadily from 20 to 40 degrees C, then very slowly from 40 degrees to 60 degrees C, while the enzyme activity decreased to 9% at 90 degrees C. The activity of the laccase changed gradually over the pH range 2.0-4.0. However, the enzyme activity was totally abrogated at the pH 8 and above. Incubation of peripheral blood cells PBCs and hepatoma HepG2 cells with laccase which were then infected with HCV did not protect the cells from HCV attack and entry, while direct interaction between HCV and the laccase at the concentrations of 2.0 and 2.5 mg/ml led to a complete inhibition of virus entry after seven days of incubation. Meantime, the laccase at the concentrations of 1.0 and 1.5 mg/ml did not display any blocking activity. The potential activity of the laccase on intracellular HCV replication in infected HepG2 cells has been examined. The laccase was capable of inhibiting HCV replication at the concentrations of 1.25 and 1.5 mg/ml after first dose of treatment for four days and at the concentrations of 0.75, 1.0, 1.25 and 1.5 mg/ml after the second dose of treatment for another four days.
目前尚无针对丙型肝炎病毒（HCV）的保护性疫苗或有效药物。对干扰素/利巴韦林治疗方案的持续病毒学应答有效率约为50%。全球许多患者使用过传统药物，尤其是草药。通过DEAE Affi - 凝胶蓝凝胶、CM - 葡聚糖凝胶G - 50和葡聚糖凝胶G - 100从平菇（糙皮侧耳）中纯化出一种漆酶，使其达到同质。在SDS - PAGE中该漆酶的分子量约为58 kDa。漆酶活性的最适pH和温度分别为pH 4.0和60℃。酶活性在20至40℃时稳步增加，然后从40℃至60℃时增加非常缓慢，而在90℃时酶活性降至9%。漆酶活性在pH 2.0 - 4.0范围内逐渐变化。然而，在pH 8及以上时酶活性完全丧失。用漆酶孵育外周血细胞（PBCs）和肝癌HepG2细胞，然后使其感染HCV，并未保护细胞免受HCV攻击和侵入，而在2.0和2.5 mg/ml浓度下HCV与漆酶的直接相互作用在孵育7天后导致病毒侵入完全被抑制。同时，1.0和1.5 mg/ml浓度的漆酶未表现出任何阻断活性。已检测了漆酶对感染的HepG2细胞内HCV复制的潜在活性。在首次给药4天后，漆酶在1.25和1.5 mg/ml浓度下能够抑制HCV复制，在第二次给药4天后，在0.75、1.0、1.25和1.5 mg/ml浓度下也能抑制HCV复制。
