Purification and Characterization of a Novel Lectin from Chinese Leek Seeds
Purification and Characterization of a Novel Lectin from Chinese Leek Seeds
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DOI：
10.1021/jf5046014
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发表时间：
2015-02-11
影响因子：
6.1
通讯作者：
Wang, Shao-yun
中科院分区：
文献类型：
--
作者：
Hong, Jing;Chen, Tao-tao;Wang, Shao-yun
通过SP Sephadex C-25离子交换层析和Sephadex G50凝胶过滤层析从韭菜籽中分离纯化了一种新的凝集素CLSL。该凝集素的分子量为23.6 kDa，由两个相同的亚基通过二硫键连接组成，这是基于还原和非还原条件下的SDS-PAGE的结论。CLSL是一种糖蛋白，糖含量为3.6%。在8.9 μ g/mL的浓度下，它对大鼠红细胞具有强效凝集活性。大鼠红细胞的血凝抑制D-果糖，甘露醇，山梨糖在20 mM的浓度。CLSL的血凝活性保持在100 ℃ 60分钟，在酸性pH条件下，但在中性和碱性pH条件下失去。红细胞凝集活性可被Ca 2+、Fe 2+和Cu 2+激活，但在10 mM时被Ba 2+灭活。圆二色谱和荧光光谱分析结果表明，Ba 2+介导的CLSL失活是由于Ba 2+诱导的CLSL构象变化所致。CLSL圆二色性的去卷积表明它是一种α-螺旋凝集素，α-螺旋和β-倍含量分别为35.8%和8.6%。CLSL还能选择性地抑制细胞增殖。
A novel lectin, CLSL, was purified from Chinese leek seeds by ion exchange chromatography on SP Sephadex C-25 and gel filtration chromatography on Sephadex G50. The lectin had a molecular weight of 23.6 kDa and was composed of two identical subunits linked by disulfide bonds, a conclusion based on SDS-PAGE under reducing and nonreducing conditions. CLSL was a glycoprotein with a carbohydrate content of 3.6%. It exerted potent agglutinating activity against rat red blood cells at a concentration of 8.9 mu g/mL. Hemagglutination of rat erythrocytes was inhibited by d-fructose, mannitol, and sorbose at the concentration of 20 mM. The hemagglutinating activity of CLSL was maintained at 100 degrees C for 60 min and under acidic pH conditions but was lost at neutral and alkaline pH conditions. The hemagglutinating activity was stimulated by Ca2+, Fe2+, and Cu2+ but inactivated by Ba2+ at a concentration of 10 mM. Ba2+-mediated inactivation of CLSL was caused by CLSL conformational change induced by barium ions, according to the results of circular dichroism and fluorescence spectroscopy. Deconvolution of the CLSL circular dichroism indicated that it was an a-helical lectin with alpha-helix and beta-fold contents of 35.8% and 8.6%, respectively. CLSL could also selectively inhibit cell proliferation.