基于星点设计-响应面法优化藜麦凝集素的提取工艺

为进一步开发利用藜麦的生物活性,利用星点设计-响应面法优选藜麦凝集素的提取工艺。以凝血活性为响应值,在单因素试验的基础上设计响应面试验,优化藜麦凝集素提取条件。结果表明:藜麦凝集素的最佳提取条件为pH 7.2,液料比15∶1(mL∶g),提取温度17℃,提取时间14.3h,该条件下,凝集素血凝活性实为3.612 36。     

木豆凝集素提纯

木豆凝集素粗样先经伴刀豆凝集素-琼脂糖凝胶（Con A-Sepharose 4B）亲和层析吸附可去除部分杂质,但凝集素本身并未被亲和吸附,而是随缓冲液排出,再经交联葡聚糖（Sephadex G-100）凝胶过滤层析,得到纯化的木豆凝集素,得率为7．8％,凝血效价提高1280倍。     

Insect peptide hormones: a selective review of their physiology and potential application for pest control

Our knowledge on primary structure, synthesis, release, receptor binding, structure-activity relationships, mode of action and degradation of, mainly, neuropeptides from insects has increased dramatically during the last 10 years or so. Here, five case studies are presented, which deal selectively with effects on: reproduction (trypsin modulating oostatic factor in mosquito); energy metabolism, locomotion and the immune system (adipokinetic hormones); water and ion balance, and feeding behaviour (diuretic hormones, kinins, sulfakinins); sex attraction (pheromone biosynthesis activating neuropeptide); and growth and development, and muscle activity (allatostatins). The literature is reviewed in the context of how the knowledge on neuropeptides has been and can be used for the design of novel, safe and selective compounds to control pest insects in the foreseeable future.     

串珠镰刀菌孢子表面的一种凝集素

 用0.2% SDS磷酸缓冲液从串珠镰刀菌(Fusarium moniliforme)孢子表面抽提蛋白质。孢子表面蛋白经DEAE-Sepharose阴离子交换柱层析和Sephacryl S-100分子筛柱层析,分离和纯化了一种凝集素。该凝集素的分子量为70 kDa,糖含量为19.8%,对兔血红细胞有很强的凝集活性,凝集活性被半乳糖特异性地抑制。EDTA和一些金属离子不影响凝集活性。     

凝集素作为海参免疫增强剂在人工养殖海参中的应用

近年来,在海参的人工养殖兴起的同时,出现了一些具有传染性的海参病害。其中较为严重的是海参“刺参腐皮综合症”(俗称化皮病),死亡率达到90%以上。通过对海参致病菌——弧菌属和假单胞菌属革兰氏阴性菌致病过程和其表面糖结构关系的分析,了解到其表面糖结构和海参致病菌致病过程密切相关。而凝集素(多价糖结合蛋白)在无脊椎动物中起非特异性免疫的作用,外源凝集素可特异地干扰病原体和宿主的结合。因此,利用凝集素作为海参免疫增强剂是防治海参病的一条有效途径。     

三疣梭子蟹C-型凝集素的原核表达和活性检测

通过RT-PCR扩增三疣梭子蟹C-型凝集素（C-type lectin like-domain protein,CTLD）基因序列,将目的基因克隆入质粒pET32a,构建原核表达重组质粒pET32a-CTLD.将重组质粒转化入大肠杆菌BL21中,通过IPTG诱导CTLD的表达,对其表达产物进行SDS-PAGE和Western blot 检测.用His GraviTrap Ni亲和层析柱及超滤离心管纯化目的蛋白,并对其进行活性检验.结果表明,构建得到CTLD基因的原核表达载体,双酶切鉴定得到与预期片段相符的外源基因插入片段,经测序与目的序列完全一致;诱导表达出相对分子质量（M） 39 600的目的蛋白,经SDS-PAGE和Western blot检测,融合蛋白成功表达;重组C-型凝集素对兔的红细胞没有明显的凝集作用,但对小鼠红细胞的凝集效价是22,而对所选5种细菌的凝集作用存在差异,其中对大肠杆菌具有明显的凝集作用,而对溶藻弧菌、哈维氏弧菌、鳗弧菌和金黄色葡萄球菌均无凝集现象.本研究结果为进一步研究C-型凝集素在免疫防御中的作用与地位提供依据.     

菜豆种质资源的植物凝集素含量测定及含量变化分析

摘要：为了研究菜豆种质中植物凝集素含量的遗传多样性及含量变化,本研究以317份菜豆品种为试验材料,利用改进的血凝法测定鲜荚中的植物凝集素含量。同时,对不同发育时期‘紫冠’和‘白珍珠’的豆荚、荚壁和种子中的植物凝集素含量进行测定分析。结果表明：菜豆种质中植物凝集素含量变幅为0.004~1.783 mg/g,变异系数为0.493,品种频率分布曲线总体显现连续性,主峰明显,呈近似正态分布。菜豆品种群体间的凝集素水平差异极显著,表现出明显的种质特异性和遗传多样性。‘紫冠’和‘白珍珠’豆荚在花后4~6天中检测到少量凝集素,表明豆荚凝集素是在花后4天开始积累。‘紫冠’与‘白珍珠’的植物凝集素含量随着豆荚生长发育都呈现出相同趋势,先上升后下降,再上升后下降,出现‘双峰’现象。     

生殖周期小鼠输卵管粘膜糖复合物结合特性

为了解输卵管粘膜糖复合物的特点和变化规律,用４种酶标植物凝集素（ＣｏｎＡ、ＳＢＡ、ＲＣＡ１２０、ＷＧＡ）作探针,研究了小鼠发情周期、妊娠早期（７ｄ）、产后（１ｄ）的输卵管粘膜凝集素结合糖复合物染色特性的变化。结果发现,输卵管粘膜与ＣｏｎＡ、ＳＢＡ、ＲＣＡ１２０的结合,无论在发情周期还是妊娠早期（７ｄ）及产后（１ｄ）,均有波动,而与ＷＧＡ的结合始终保持最强阳性。提示输卵管粘膜凝集素结合特性的变化,可能与生殖周期激素的波动和胚泡的调节有关。     

Serum levels of chicken mannan-binding lectin (MBL) during virus infections; indication that chicken MBL is an acute phase reactant

Mannan-binding lectin (MBL) is a serum collectin which is believed to be an opsonin of the innate immune defence against various microorganisms. MBL is a minor acute phase reactant in man. We investigated the concentration of serum MBL in chickens infected with infectious bronchitis virus (IBV) and infectious laryngotracheitis virus (ILTV). The concentration of serum MBL increased about twofold (from approximately 6 to 12 μg/ml) due to these viral infections. The concentration peaked 3–7 days after infection with IBV, and 3–5 days after ILTV infection, depending on the ILTV strain used. The increased levels returned to normal values 6–10 days after infection. The results indicated that MBL is a minor acute phase reactant in chickens.