抗肿瘤文蛤糖肽(MGP0405)的分离纯化及性质研究

Isolation and Characterization of Glycopeptide MGP0405 from Meretrix meretrix

目的:分离纯化海洋软体动物文蛤糖肽MGP0405,并对其性质进行初步研究。方法:文蛤粗提液经超滤、HP 20大孔吸附层析、Bio-gel凝胶过滤层析等方法纯化得到MGP0405。电泳结果经考马斯亮蓝染色和阿尔新蓝染色表现为单一条带。同时对MGP0405进行紫外和红外光谱分析以及氨基酸和单糖组成分析。采用MTT法测定MGP0405体外抗肿瘤活性。结果:MGP0405是分子量为9 655 Da的糖肽,等电点在pH 7.0附近,在波长272 nm有特征吸收,红外结果显示MGP0405具有糖肽的一般特征吸收,多糖部分以β-糖苷键连接;氨基酸组成分析显示MGP0405富含甘氨酸(Gly)、丙氨酸(Ala)、缬氨酸(Val)、蛋氨酸(Met)、亮氨酸(Leu)、异亮氨酸(Ile),不含色氨酸(Trp),单糖组成分析显示MGP0405糖链部分由单一的葡萄糖组成。MGP0405(200μg.mL-1)对人鼻咽癌KB细胞的抑制率达到69%。结论:文蛤提取物MGP0405是一种具有体外抗肿瘤活性的糖肽类物质。

AIM： To investigate the isolation, purification and identification of Meretrix meretrix glycopeptide, MGP0405. METHODS： MGP0405 was isolated by ultrafihration and purified on HP 20 adsorption chromatography and Bio-gel gel filtration. SDS- PAGE, Ultraviolet spectra, Fourier-transform infrared spectra scanning, amino acid analysis and monosaccharides composition analysis were used to characterize MGP0405. The anticancer activities of MGP0405 were evaluated by MTT assay. RESULTS： MGP0405 was a kind of natural glycopeptide with the MW of 9 655 Da. UV spectrum of MGP0405 showed strong characteristic absorption at 272 nm. IR spectrum of MGP0405 indicated general characteristic absorption of glycopeptide and β-glycosidic linkage. The peptide and sugar chain of the MGP0405 were mainly made up of glycine, alaine, valine, methionine, leucine, isoleucine and glucose with amino acids constitution and thin layer chromatographic analysis, repectively. The inhibitory rate of MGP0405 affected on KB cell line was 69% at the concentration of 200μg·mL^-1. CONCLUSION： MGP0405 is a kind of glycopeptide with antitumor activity in vitro.