重组乳酸乳球菌对模拟胃肠道的耐受力研究

[目的]研究重组菌株在不同p H胃液和胆盐浓度肠液中的生存情况,验证重组菌株能否在肠道中发挥作用,为其制备基因工程活载体疫苗、新型免疫型微生态制剂及功能发酵食品提供理论依据。[方法]人工模拟人体胃肠道环境,研究表达金黄色葡萄球菌纤黏蛋白原凝集素A(Clf A)的重组乳酸乳球菌MG1363/p MG36c-clf A菌株在不同p H胃液和胆盐浓度的肠液中的耐受力。[结果]重组菌株在p H 3.0的人工胃液中处理2 h后,存活率约为88.6%;在0.3%胆盐浓度的人工肠液中处理2和4 h后,存活率约为83.6%和68.2%。[结论]重组菌株对胃肠道环境有较强的耐受力,适合制备基因工程活载体疫苗、新型免疫型微生态制剂及功能发酵食品。     

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。     

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.     

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。     

Influence of certain soybean antinutritional factors supplemented to a casein-based semipurified diet on intestinal and liver morphology in fingerling rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>

To investigate the cause of morphological changes occurring in the liver and intestine of rainbow trout Oncorhynchus mykiss fed defatted soybean meal (SBM)-based non-fish meal diets, morphological observations were conducted on fish fed casein-based semipurified diets supplemented with soybean antinutritional factors (soya saponin, soya isoflavone, soya lectin, oligosaccharide, Ca-phytate and their mixture). Hepatocytes and the epithelial cells in the hepatic ducts were not atrophied in any of the treatments. Lack of microvilli and pinocytotic vacuoles, and fatty degeneration of the epithelial cells were observed in the distal intestine of fish fed diets containing soya saponin. The proliferation of connective tissue in the mucosal folds and submucosa was shown in the distal intestine of fish fed the diet containing all substances including lectin. These results suggest that both saponin and lectin are the responsible factors in SBM for the occurrence of morphological changes of the distal intestine in rainbow trout fed SBM-based diets.     

血凝法测定饲料中植物凝集素含量

通过研究植物凝集素(lectin)的血细胞凝集活性与其浓度的关系，提出了用血凝法测定饲料中lectin的新方法，并探讨了试样粉碎粒度、脱脂方法、脱脂时间、抽提时间、抽提次数等测定条件对测定结果的影响。结果表明，lectin的活力与浓度之间存在高度线性相关(R^2=0．99)。血凝法测定饲料中lectin的含量时，以样品粉碎过40目、样品与30～60℃石油醚或乙醚比例(W／V)1：8脱脂8h、样品与生理盐水(W／V)1：8抽提8h为宜。在上述条件下测定，回收率可达88％～102％。经过对8种不同的饲料及原料样品lectin含量的测定，平均相对偏差为0．9％～2．4％，变异系数为1．3％～3．3％。结果表明，利用血凝法可快速测定饲料中的lectin含量。     

Modulating effect of acorn barnacle C-type lectins on the crystallization of calcium carbonate

ABSTRACT:   The modulating effect of invertebrate C-type lectins on the crystallization of calcium carbonate was investigated. The multiple C-type lectins, named BRA-1, -2 and -3, isolated from the acorn barnacle Megabalanus rosa inhibited the nucleation and growth of calcium carbonate crystals. Among BRA, BRA-2 most efficiently inhibited the crystal nucleation of aragonite and calcite at the concentrations of > 3.3 and > 26 μg/mL, respectively. The inhibitory activities of BRA were enhanced by the addition of various biomolecules such as D-glucosamine, D-galactosamine, chitosan oligosaccharides, L-arginine and L-aspartic acid. Although the crystals of aragonite and calcite were formed in the presence of lower concentrations of BRA, the shape and size of the crystals were changed. These results further indicate the participation of the lectins in biomineralization.     

绵羊子宫内膜的凝集素结合特性

用５种酶标植物凝集素（ｃｏｎＡ，ＳＢＡ，ＷＧＡ，ＵＥＡ，ＲＣＡ）作探针，研究了间情期和妊娠期绵羊子宫内膜上皮和间质糖复合物的变化。与间情期相比，妊娠期子宫内膜上皮ＣｏｎＡ和ＷＧＡ染色明显增强，特别是ＵＥＡ染色由阴性转变为强阳性，ＳＢＡ染色没有明显变化。在间质石ＢＡ和ＵＥＡ染色由阴性转变为中阳性，而ＣｏｎＡ和ＷＧＡ染色无明显变化。无论间情期或妊娠期，子宫内膜上皮和间质的ＲＣＡ染色均为阴性。子宫内膜上皮和间质糖复合物质和量的变化，可能与子宫各部功能和妊娠有关。     

Comparison of the amino acid sequences of acorn barnacle lectins showing different inhibitory activities toward the crystal growth of calcium carbonate

ABSTRACT: The amino acid sequence of a D -galactose-binding lectin isolated from the hemolymph of the acorn barnacle Balanus rostratus was determined. The lectin (BRL) ( M _r 120K) is a multimeric protein whose subunit consists of 182 amino acids. The amino acid sequence was compared with those of multiple lectins (BRA-2, BRA-3) from Megabalanus rosa to explore the relationship between the structures and the inhibitory activity toward the crystal growth of calcium carbonate. Although BRL was 46% identical to BRA-2 and 15% identical to BRA-3, the lectin had no inhibitory activity, unlike BRA-2 and BRA-3. Both the number and the localization of acidic amino acid residues and their amide forms were different among them. Observations by scanning electron microscopy revealed modifications in the size and morphology of the calcium carbonate crystals grown in the presence of the lectins.