Purification of melibiose-binding lectins from two cultivars of Chinese black soybeans

• 来源期刊: 生物化学与生物物理学报（英文版）
• 关键词: purification melibiose-binding lectin Chinese black soybean
• 年，卷（期）: 2008,（12）
• 页码范围: 1029-1038
• 页数: 10页
• 语种: 英文
• DOI: 10.1111/j.1745-7270.2008.00488.x

摘要

A dimeric 50 kDa melibiose-binding leetin was isolated from the seeds of the cultivar of soybean (Glycine max), called the small glossy black soybean. The isolation procedure comprised ion exchange chromatography on Q Sepharose, SP Sepharose and Mono Q followed by gel filtration on Superdex 75. The lectin was adsorbed on all three ion exchangers, and it exhibited an N-terminal sequence identical to that of soybean iectin. Of all the sugars tested, melibiose most potently inhibited the hemagglutinating activity of the lectin, which was stable between pH 3-12 and 0-70℃. The lectin evoked maximal mitogenic response at about the same molar concentration as Con A. However, the response was much weaker. The soybean iectin inhibited the activity of HIV-1 reverse transcriptase as well as the proliferation of breast cancer MCF7 cells and hepatoma HepG2 cells with an IC<,50> of 2.82 μM, 2.6 μM and 4.1 μM, respectively. There was no antifungal activity. Another lectin was isolated from a different cnltivar of soybean called little black soybean. The lectin was essentially similar to small glossy black soy-bean iectin except for a larger subunit molecular mass (31 kDa), a more potent mitogenic activity and lower thermostability. The results indicate that different cultivars of soybean produce lectins that are not identical in every aspect.