Biogenic nanostructured silica

Silicon is by far the most abundant element in the earth crust and also is an essential element for higher plants, yet its biology and mechanisms in plant tolerance of biotic and abiotic stresses are poorly understood. Based on the molecular mechanisms of the biosilicification in marine organisms such as diatoms and sponges, the cell wall template-mediated self-assembly of nanostructured silica in marine organisms and higher plants as well as the related organic molecules are discussed. Understanding of the templating and structure-directed effects of silicon-processing organic molecules not only offers the clue for synthesizing silicon-based materials, but also helps to recognize the anomaly of silicon in plant biology.     

A note on the use of protease inhibitors during chromatin fractionation on hydroxyapatite columns

Summary It was found that NaHSO₃ present in the eluents enabled full and reproducible recovery of chromosomal proteins from a hydroxyapatite column. Another protease inhibitor PMSF, did not have that effect.     

不同水,陆稻抗旱性与剑叶中可溶性蛋白变化的关系

不同水,陆稻品种,同一品种在不同季节栽培时,其抗旱性均有差异;用考马斯亮蓝染色法检测表明,它们的剑叶中可溶性蛋白含量变化模式也不一样,且与抗旱性不呈线性关系,ＳＤＳ－ＰＡＧＥ图谱分析表明,干旱引起蛋白质成分的变化表现在整体水平上,而单一成分的变化极少。     

苍耳粗蛋白生物活性的研究

采用不同饱和度硫酸铵盐析法进行不同生长发育时期苍耳叶片和种子粗蛋白的提取及分级分离,测定其对酵母菌生长、ATPase活性和线粒体呼吸的抑制作用．结果表明：50％和80％饱和度硫酸铵环境中析出的成熟种子粗蛋白的抑制效应最为显著．     

Production of pharmaceutical proteins in milk

There is every reason to expect that it will be possible within the next few years to begin to use farm animals to produce large quantities of some of the human proteins that are needed for the treatment of disease. Revolutionary new opportunities for the production of novel proteins in milk have been created by the development of methods for gene transfer. Exploitation of these opportunities depends upon selection and cloning of milk protein genes and identification of the sequences that govern tissue specific hormonally induced expression in the mammary gland. Studies with three genes, ovine -lactoglobulin, rat -casein and whey acidic protein of rat and mouse, suggest that they may all meet this requirement. Fragments of the ovine -lactoglobulin, murine whey acidic protein and rabbit -casein genes have directed production of novel proteins in the milk of transgenic mice, sheep, rabbits and pigs. The proteins were biologically active and usually co-migrated with authentic proteins. In early experiments, protein concentration was low, but our recent observations suggest that fusion genes containing genomic clones direct production of concentrations of protein that are suitable for commercial exploitation. In the longer term, two approaches may offer the potential of more reliable expression. Control elements capable of directing expression that is independent of site of insertion of the gene, but dependent on the number of copies of the gene, have been identified for a small number of genes. The availability of such elements for the milk protein genes would increase the reliability of gene expression considerably. Alternatively, targeted mutation of genes may allow the insertion of coding sequences within an existing gene so avoiding position effects.     

四种植物蛋白的成分与营养学特性分析

分析了4种植物蛋白的氨基酸组成特征和营养学特性。玉米蛋白粉、大豆粉、棉籽蛋白粉、花生饼粉蛋白质质量分数分别为61.60%,38.18%,51.49%,43.15%。大豆粉氨基酸组成比较均衡;棉籽蛋白粉、花生饼粉中多种必需氨基酸组成与大豆蛋白接近,但蛋氨酸含量较低;玉米蛋白粉富含亮氨酸、异亮氨酸、缬氨酸等支链氨基酸,但其中赖氨酸、色氨酸含量明显低于其他3种植物蛋白。建议根据蛋白资源的氨基酸特色组成,合理搭配互补,以提高谷物蛋白质营养价值。     

抗Y-box结合蛋白冷休克域单克隆抗体的制备及其初步应用

固相法合成Y -box结合蛋白冷休克域部分片段“14肽”(H2 N NGYGFINRNDTKED COOH ,简称ND) ,用不同载体蛋白经戊二醛一步法偶联得到免疫抗原 (BSA ND)和检测抗原 (OVA ND) .用免疫抗原免疫BLAB c小鼠 ,经间接法ELISA检测 ,得到对ND有足够免疫应答的小鼠 .采用常规单克隆抗体制备的方法 ,得到 3株能稳定产生和分泌抗ND单抗的克隆细胞株 ,单抗的亚型均为IgM .WesternBlotting结果显示 :该单抗能识别中华大蟾蜍 (Bufobufogar garizans)Ⅰ、Ⅱ期卵母细胞中的热稳定Y box结合蛋白p5 4 ,并能识别中华大蟾蜍高、低温卵中一种分子量约为 80kD的蛋白 (简称p80 ) .由于p80在低温卵中含量高于高温卵中 ,推测可能是高温卵和低温卵中差异表达的Y box结合蛋白之一 .     

热激蛋白的分子进化研究

热激蛋白是细胞内含量最丰富的蛋白质之一,在各种生物体内广泛分布.近年来对热激蛋白的研究已深入到结构、性质、功能等各面,其研究主要集中在:1)作为分子伴侣协助细胞内肽链的折叠;2)参与MHCⅠ类的分子呈递;3)使抗原通过内吞作用进入靶细胞;4)肿瘤免疫和分子疫苗开发.然而,虽然热激蛋白的研究已成为医学、生物学上的热点,其在分子进化上的研究也日渐增多,但这方面的报道仍然较少,本文主要从热激蛋白分子进化方面作一综述,这对理论研究、生物进化分析上都有着重要的意义.