YP3:食用菌榆黄蘑中新的植物病毒抑制物蛋白

摘要

Many proteins from mushrooms can be used as potential antiviral agents,and in plant protection.An antiviral protein(YP3)was isolated from fruiting bodies of the fungus Pleurotus citrinopileatus with a procedure involving ammonium sulfate precipitation,ion-exchange chromatography on DEAE-cellulose,and gel filtration on SephacrylTMS-200 High Resolution.The molecular weight of protein was determined to be about 27.6 kDa by Sodium dodecyl sulfate -polyacryl-amide gel electrophoresis(SDS-PAGE).The amino acid analysis indicated that it was similar to some other antiviral proteins.The protein was almost not sacchariferous.The sequence of N-terminal of YP3 was NRDVAACARFIDDFCDTLTP,which had no homology with other sequences in GenBank.YP3 at 0.24 mg/L achieved 50.0% inhibition of Tobacco mosaic virus(TMV 20 mg/L)lesions in Nicotiana glutinosa leaves;YP3 is inactive to some bacteria and fungi tested;YP3 inhibited stomach cancer cell line MGC-803,liver cancer cell line SMMC-7721 and lung cancer cell line SPC-Alwith an IC50,of about 20 mg/L.%食用菌中含有多种抗病毒蛋白,可用于植物保护.采用硫酸铵分级沉淀、DEAE-纤维素离子交换层析和SephacrylTMS-200凝胶层析方法,从食用菌榆黄蘑新鲜子实体中提取到一单亚基蛋白,命名为YP3.利用SDS-聚丙烯酰胺不连续凝胶电泳初步估计其分子量大约为27.6 kDa.氨基酸组成分析表明该蛋白非常类似其它的抗植物病毒蛋白,并且几乎不含糖.其N-末端序列为NRDVAACARFIDDFCDTLTP,在GenBank中没有找到同源序列.浓度为0.24 mg/L时蛋白YF3对烟草花叶病毒(TMV 20 mg/L)侵染心叶烟的抑制率为50%.同时还发现YP3对供试的细菌和真菌没有抑制活性,对胃癌细胞株MGC-803、肝癌细胞株SMMC-7721、肺癌细胞株SPC-A1的细胞增殖具有一定的抑制作用,其IC50大约为20 mg/L.