抗肿瘤转移多聚β肽聚乙二醇化的研究

目的:研究抗肿瘤转移多聚β肽的聚乙二醇(PEG)化的方法及其作用。方法:采用甲氧基聚乙二醇丙醛(mPEGALD5000)修饰多聚β肽;采用电泳和成像分析系统检测修饰率。以粘附实验检测生物活性。结果:(1)二聚β肽(β2)的修饰率为66.7%,三聚β肽(β3)为52.7%。(2)最佳反应条件为:pH值为5,多聚β肽和mPEGALD5000的摩尔之比为1∶10,反应温度为4℃,反应时间为24h。(3)修饰后产物在4℃下可稳定放置50d。(4)修饰后产物水溶解度增加。(5)β2,β2-PEG,β3和β3-PEG对SMMC-7721和HCCLM6细胞与纤连蛋白(FN)粘附均具有显著的抑制作用(P<0.01),而且PEG修饰后作用显著增强(P<0.05或P<0.01)。结论:采用mPEGALD5000能有效地将多聚β肽PEG化。多聚β肽和PEG修饰物对肿瘤细胞与FN的粘附具有特异的抑制作用,且PEG修饰后作用增强。

Study on pegylation of antineoplasm metastatic poly-beta peptide

AIM:To study the methods of the pegylation of poly beta peptide and its anti-metastasis effect. METHODS: Using methoxy-polyethylene glycol-propylaldehyde(mPEGALD_(5000)) to modify poly-β peptide. The modification rate can be detected by electrophoresis and imaging analysis system. The bioactivity was detected by the adhesion experiment. RESULTS: (1) The modification rate of β dipeptide was 66.7 % by mPEGALD_(5000), while β tripeptide was (52.7 %). (2) The optimal pH for modification was around 5-6, the optimal molar ratio between poly β_2 peptide and mPEGALD_(5000) was 1∶10. Also, the optimal duration and temperature for the modification was for 24 h at 4 ℃. (3) The product of pegylation can be placed at 4 ℃ for 50 d steadily. (4) The solubility of product was increased greatly. (5) The inhibition of peptides on the adhesion of SMMC-7721 and HCCLM6 hepatoma cells to fibronectin(FN) was obvious(P<(0.01)). The inhibition effect on the adhesion of pegylated polypeptides was stronger than that of polypeptides(P<(0.05), P<0.01). CONCLUSION: The mPEGALD_(5000) can pegylate the poly-beta peptide effectively. The poly-beta peptides and their products of the pegylation can inhibit the adhesion of tumor cells to FN obviously exhibiting more strong inhibition.