Zhang Bochao, Zhang Xuewu
College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China.
Biotechnol Prog. 2013 Sep-Oct;29(5):1230-8. doi: 10.1002/btpr.1769. Epub 2013 Jul 8.
Spirulina platensis is a multicellular edible blue-green alga with abundant proteins (∼ 60%). No report is available on the antitumor polypeptides from the whole proteins of S. platensis. In this study, for the first time, an antitumor polypeptide Y2 from trypsin digest of S. platensis proteins was obtained by using freeze-thawing plus ultrasonication extraction, hydrolysis with four enzymes (trypsin, alcalase, papain, and pepsin), and gel filtration chromatography. The results showed that the degree of hydrolysis can be ordered as: trypsin (38.5%) > alcalase (31.2%) > papain (27.8%) > pepsin (7.1%). For MCF-7 and HepG2 cells, at 250 µg/mL, the maximum inhibitory rate of Y2 was 97%, while standard drug 5-FU was 55 and 97%, respectively. Furthermore, the nanoencapsulation of Y2 with chitosan (CS) was also investigated. After nanoencapsulation, the maximum encapsulation efficiency and polypeptides contents are 49 and 15%, respectively; and the antitumor activity is basically not lost. These data demonstrated the potential of nanopolypeptides (Y2-CS) in food and pharmaceutical applications.
钝顶螺旋藻是一种多细胞可食用蓝绿藻，含有丰富的蛋白质（约60%）。关于钝顶螺旋藻全蛋白中的抗肿瘤多肽尚无相关报道。在本研究中，首次通过冻融加超声提取、用四种酶（胰蛋白酶、碱性蛋白酶、木瓜蛋白酶和胃蛋白酶）水解以及凝胶过滤色谱法，从钝顶螺旋藻蛋白的胰蛋白酶消化物中获得了一种抗肿瘤多肽Y2。结果表明，水解程度顺序为：胰蛋白酶（38.5%）＞碱性蛋白酶（31.2%）＞木瓜蛋白酶（27.8%）＞胃蛋白酶（7.1%）。对于MCF-7和HepG2细胞，在250μg/mL时，Y2的最大抑制率为97%，而标准药物5-FU分别为55%和97%。此外，还研究了用壳聚糖（CS）对Y2进行纳米包封。纳米包封后，最大包封率和多肽含量分别为49%和15%；且抗肿瘤活性基本未丧失。这些数据证明了纳米多肽（Y2-CS）在食品和制药应用中的潜力。
