Departamento de Bioquímica, Universidade Federal de Pernambuco, Avenida Professor Moraes Rêgo s/n, Cidade Universitária, Recife, Pernambuco, Brazil.
Comp Biochem Physiol B Biochem Mol Biol. 2011 May;159(1):57-63. doi: 10.1016/j.cbpb.2011.02.001. Epub 2011 Feb 18.
A novel lectin was isolated from Bothrops leucurus snake venom using a combination of affinity and gel filtration chromatographies. The lectin (BlL) agglutinated glutaraldehyde-treated rabbit and human erythrocytes with preference for rabbit erythrocytes. Galactose, raffinose, lactose, fetal bovine serum and casein inhibited lectin-induced rabbit erythrocyte agglutination. BlL, with a molecular mass of 30 kDa and composed of two subunits of 15 kDa, showed dependence on calcium. BlL is an acidic protein with highest activity over the pH range of 4.0-7.0 and stable under heating to 70°C. Fluorescence emission spectra showed tryptophan residues partially buried within the lectin structure. The percentages of secondary structure revealed by circular dichroism were 1% α-helix, 44% β-sheet, 24% β-turn and 31% unordered. BlL showed effective antibacterial activity against Gram-positive bacteria Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis with minimal inhibitory concentrations of 31.25, 62.25 and 125 μg/mL, respectively. In conclusion, B. leucurus snake venom contains a galactoside-binding lectin with antibacterial activity.
一种新型凝集素从矛头蝮蛇蛇毒中分离出来，采用亲和层析和凝胶过滤层析相结合的方法。该凝集素（BlL）与戊二醛处理的兔和人红细胞发生凝集，对兔红细胞有偏好。半乳糖、棉子糖、乳糖、胎牛血清和酪蛋白抑制凝集素诱导的兔红细胞凝集。BlL 的分子量为 30 kDa，由两个 15 kDa 的亚基组成，依赖于钙。BlL 是一种酸性蛋白，在 pH 值为 4.0-7.0 范围内活性最高，在 70°C 加热下稳定。荧光发射光谱表明色氨酸残基部分埋藏在凝集素结构中。圆二色性揭示的二级结构百分比为 1%α-螺旋、44%β-折叠、24%β-转角和 31%无规卷曲。BlL 对革兰氏阳性菌金黄色葡萄球菌、粪肠球菌和枯草芽孢杆菌具有有效的抗菌活性，最小抑菌浓度分别为 31.25、62.25 和 125 μg/mL。总之，矛头蝮蛇蛇毒含有一种具有抗菌活性的半乳糖结合凝集素。
