Parkash A, Ng T B, Tso W W
Department of Biochemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
J Pept Res. 2002 May;59(5):197-202. doi: 10.1034/j.1399-3011.2002.00978.x.
A peptide designated charantin, with a molecular mass of 9.7 kDa, was isolated from bitter gourd seeds. The procedure comprised affinity chromatography on Affi-gel blue gel, ion-exchange chromatography on Mono S and gel filtration on Superdex 75. The N-terminal sequence of charantin exhibited marked similarity to that of the 7.8-kDa napin-like peptide previously isolated from bitter gourd seeds. Charantin inhibited cell-free translation in a rabbit reticulocyte lysate system with an IC50 of 400 nm, a potency lower than that of the previously reported small ribosome-inactivating protein gamma-momorcharin (IC50 = 55 nm) which also exhibited an abundance of arginine and glutamate/glutamine residues. Charantin reacted positively in the N-glycosidase assay, yielding a band similar to that formed by the small ribosome-inactivating proteins gamma-momorcharin and luffin S.
从苦瓜种子中分离出一种名为苦瓜素的肽，其分子量为9.7 kDa。该分离过程包括在Affi-gel蓝凝胶上进行亲和层析、在Mono S上进行离子交换层析以及在Superdex 75上进行凝胶过滤。苦瓜素的N端序列与先前从苦瓜种子中分离出的7.8 kDa类napin肽的N端序列具有显著相似性。苦瓜素在兔网织红细胞裂解物系统中抑制无细胞翻译，IC50为400 nM，其效力低于先前报道的小核糖体失活蛋白γ-苦瓜素（IC50 = 55 nM），γ-苦瓜素也含有大量的精氨酸和谷氨酸/谷氨酰胺残基。苦瓜素在N-糖苷酶测定中呈阳性反应，产生的条带与小核糖体失活蛋白γ-苦瓜素和丝瓜素S形成的条带相似。
