一种槲寄生多肽的一级结构分析和抗肿瘤活性

Determination of primary structure of a novel peptide from mistletoe and its antitumor activitv

目的 研究槲寄生枝叶中肽类抗肿瘤活性成分并阐明其结构。方法 应用阳离子交换、凝胶过滤及高效液相等色谱方法进行分离纯化,基质辅助激光解吸飞行时间质谱用于测定质量数。采用Edman降解结合酶解法确定多肽的完整序列。对多肽用MTT法进行体外抗肿瘤活性评价。结果 从槲寄生中纯化出一种新的多肽,命名为槲寄生毒素B2(viscotoxin B2),其一级结构为KSCCKNTTGRNIYNTCRFAGGSRERCAKLSGCKIISASTCPSDYPK。Viscotoxin B2对体外培养的大鼠成骨样肉瘤细胞的IC50为1.6 mg·L～1。结论 Viscotoxin B2与白果槲寄生中的槲寄生毒素有很高的同源性,并具有较强的抗肿瘤活性。

Aim To study the antitumor peptide components in the stems and leaves of mistletoe ( Viscum coloratum ( Kom. ) Nakai) , the primary structure of the novel peptide was elucidated. Methods Cation exchange, gel filtration and HPLC were employed for isolation and purification. Matrix Assisted Laser Desorption Ionization-Time of Flight-Mass Spectrometry was used to determine the mass. The complete amino acid sequence of the novel peptide was obtained by Edman degradation combined with enzyme digestion. The antitumor activity of the peptide in vitro was studied with MTT method. Results The primary stucture of the peptide named as viscotoxin B2 is KSCCKNTTGRNIYNTCRFAGGSR ERCAKLSGCKIISASTCPSDYPK. The IC50 value of viscotoxin B2 on the Rat Osteoblast-like Sarcoma 177 2. 8 cells in vitro is 1. 6 mg · L -1 . Conclusion Viscotoxin B2 in V. coloratum, which has high similarity with viscotoxins from V. album, showed antitumor activity.