乳铁蛋白纯化方法的优化

将纯度为50%左右的乳铁蛋白溶液加入带羧甲基的弱酸性阳离子交换剂CM-Sepharose Fast Flow进行动态吸附,采用质量分数为1.6%和5%的NaCl溶液进行阶跃洗脱;并对层析过程和接样方法进行了优化.结果表明,经过重复层析和优化方法接样,乳铁蛋白纯度可达96.7%.     

斑点免疫金渗滤法检测抗乳铁蛋白多克隆抗体特异性研究

采用斑点免疫金渗滤法对抗乳铁蛋白多克隆抗体特异性进行检测.结果表明金探针具有很强的选择性,斑点免疫金渗滤法能准确快速地检测出多克隆抗体的特异性.     

微量甲醛检测方法的研究进展

目前,甲醛的检测方法主要有分光光度法、气相色谱法、液相色谱法和电化学法以及其他方法。不同的分析方法有不同优缺点和适用范围,该文章主要综述了近年来甲醛的检测方法的研究进展。     

转基因牛乳中重组人乳铁蛋白中试纯化工艺的建立及其活性分析

目的建立转基因牛乳中重组人乳铁蛋白(recombinant human lactoferrin,rh LF)的中试纯化工艺,并分析纯化的rh LF的活性。方法以含rh LF的转基因牛乳为原料,通过陶瓷膜分离技术除菌,一步阳离子交换层析,非离子型去污剂与金属络合剂去除内毒素,以及超滤浓缩脱盐,冷冻干燥制备重组蛋白纯品等步骤纯化rh LF,采用SDSPAGE、凝胶过滤色谱(SEC-HPLC)法和反相色谱(RP-HPLC)法分析rh LF的纯度;ELISA法检测rh LF的含量;鲎试剂法检测rh LF的内毒素含量;圆二色谱技术分析rh LF的二级结构;并检测rh LF的铁结合能力和抑菌活性。结果纯化的rh LF的平均纯度可达96%,内毒素含量小于0.5 EU/mg,整个工艺回收率达75%,且具有与天然人乳铁蛋白(human lactoferrin,h LF)相近的二级结构及正常的铁结合能力和抑菌活性。结论建立的牛乳中rh LF的中试纯化工艺简便高效,适用于rh LF的规模化生产。     

人乳铁蛋白异源表达的研究进展

乳铁蛋白（Lactoferrin,lactotransferrin,简称LF、LTF）是一种天然的、具有免疫功能的糖蛋白,1938年Sorensen M和Sorensen SPL首次从牛乳中分离出牛乳铁蛋白（bovine lactoferrin,简称BLF）;1960年Groves从人乳中首次分离出人乳铁蛋白（human lactoferrin,简称HLF）。由于人乳的来源有限,不可能通过直接提取的方法来生产人乳铁蛋白,所以目前研究较多的是通过基因重组的方法进行异源表达。     

微量磷单质检测方法研究进展

随着科学技术的发展和废物无害化、资源化利用的需要,微量磷单质定性定量分析方法得到了不断地改进和提高。本中就目前微量磷单质主流分析方法——分光光度法和气相色谱法进行了详细的探讨,分析了新型检测技术,如质谱法、X射线荧光光谱法、电感耦合等离子体法在磷单质检测中的应用,总结了每种方法的检测流程、检出限、存在的问题等。希望能够为微量磷单质分析检测方法的快速、合理选择提供参考,促进微量磷单质分析方法的进一步完善。     

乳铁蛋白介导的肺靶向纳米脂质载体的研究进展

纳米脂质载体属纳米给药体系,是在固体脂质纳米粒基础上发展起来的新型靶向给药系统,以生物相容性好的固态和液态脂质混合作为载体材料,将药物包裹于类脂核中,具有胶体载体如脂质体和纳米乳的优势,可用作抗肿瘤药物的靶向载体,同时,相比而言,纳米脂质载体雾化稳定性更好,在气道中具有良好的耐受性和理想的肺沉积率,适用于雾化吸入给药,该给药方式可使药物直达病灶,雾滴长时间滞留在肿瘤部位,发挥长效作用。为进一步提高药物的生物利用度、增强肺癌靶向性,可用乳铁蛋白对纳米脂质载体进行表面修饰。乳铁蛋白属转铁蛋白家族,正常肺组织中转铁蛋白受体呈阴性或低表达,而在非小细胞肺癌中转铁蛋白的阳性表达率远远高于正常肺组织,存在过度表达现象,可利用乳铁蛋白作为配体修饰纳米脂质载体,通过转铁蛋白介导的方式增加药物在肺癌细胞内的富集,受体介导的内吞可以进一步促进负载药物的纳米脂质载体的细胞摄取。     

室内甲醛检测方法及防治措施研究进展

针对室内甲醛检测方法及防治措施研究进展进行分析,阐述了甲醛对人体的危害性,并且分析了甲醛的具体来源。结合这些内容,阐述了如何对室内甲醛进行检测,分别介绍了分光光度法和色谱法两种过检测技术,最后总结了如何预防室内甲醛超标。     

乳球噬菌体DNA的快速分离和纯化法

简要介绍了乳球噬菌体ＤＮＡ的快速分离和纯化方法，比起传统方法来，只需要４～６ｈ。     

串联阴阳离子交换色谱分离牛初乳中乳铁蛋白与IgG

脱脂牛初乳用浓度为6 mol/L的盐酸调节其pH至4.0,以5 000 r/m in离心分离20 m in除去酪蛋白制得乳清,缓慢滴加浓度为1 mol/L的氢氧化钠回调pH至6.8;处理后的乳清经截留相对分子质量为50 000的组分并超滤稀释后,再经过阴阳离子交换串联色谱,乳铁蛋白(Lf)吸附于CM Sepharose Fast F low,免疫球蛋白G(Immunoglobu lin G,IgG)吸附于DEAE Sepharose Fast F low;阳离子交换柱用c(NaC l)=0.27 mol/L、0.85 mol/L的水溶液阶跃洗脱,得到色谱纯度为96.6%的Lf产品,阴离子交换柱用c(NaC l)=17 mmol/L、51 mmol/L的水溶液阶跃洗脱,得到色谱纯度为95%的IgG产品。     

二甲基硫醚提纯的工艺改造

通过对精制二甲基硫醚的工艺流程和设备的技术改造,使精二甲基硫醚的纯度显著提高,烧碱消耗降低１００ｔ／ａ,污水排放大大减少,环保投资节省２０ 余万元／年,经济效益增加３５ 万元／年。     

DBS类聚丙烯成核剂纯化技术

DBS及其衍生物是一类应用效果好、市场前景比较广阔的聚丙烯塑料透明化成核剂。分析了DBS类成核剂产生异味的原因，对不同的除味方法进行介绍，并简要评述。     

Purification of an Inducible DNase from a Thermophilic Fungus

The ability to induce an extracellular DNase from a novel thermophilic fungus was studied and the DNAse purified using both traditional and innovative purification techniques. The isolate produced sterile hyphae under all attempted growing conditions, with an average diameter of 2 μm and was found to have an optimal temperature of 45 °C and a maximum of 65 °C. Sequencing of the internal transcribed region resulted in a 91% match with Chaetomium sp., suggesting a new species, but further clarification on this point is needed. The optimal temperature for DNase production was found to be 55 °C and was induced by the presence of DNA and/or deoxyribose. Static growth of the organism resulted in significantly higher DNase production than agitated growth. The DNase was purified 145-fold using a novel affinity membrane purification system with 25% of the initial enzyme activity remaining. Electrophoresis of the purified enzyme resulted in a single protein band, indicating DNase homogeneity.     

Candida sp.脂肪酶的纯化及其性质

采用简单的两步法-离子交换层析和疏水层析法,对Candida sp. 99-125脂肪酶进行了纯化,比活提高了10.0倍,达到27200 U/mg,回收率为35.5%. SDS-PAGE电泳分析显示该酶的分子量约为38 kDa. 酶学性质研究表明,该酶最适反应温度为40℃,最适反应pH值为8.5,在室温下具有良好的稳定性. 钙离子和Tween80能够促进提高脂肪酶的活性,而铁离子、铜离子和SDS对其有明显的抑制作用.     

Ionic Liquid-Based Three Phase Partitioning (ILTPP) for Lactoferrin Recovery

A novel technique called ionic liquid-based three phase partitioning (ILTPP) that combines the interesting properties of ionic liquids as extracting solvents and the advantages of interfacial partitioning for protein recovery is presented in this work. The ternary system BmimBF₄/NaH₂PO₄/H₂O is used to accumulate lactoferrin (a bovine whey with important nutraceutical properties) at the liquid-liquid interface. Between 74% and 99% of the lactoferrin is recovered at the interface, depending on the temperature, the ionic liquid content, and, especially, the salt concentration. Consequently, ILTPP can be seen as a promising technique that may overcome the drawbacks of conventional techniques to recover lactoferrin.     

Purification and Characterization of Iso-Ribonucleases from a Novel Thermophilic Fungus

A thermophilic fungus previously isolated from composted horse manure was found to produce extracellular iso-RNases that were purified 127.6-fold using a combination of size exclusion chromatography and a novel affinity membrane purification system. The extent of purification was determined electrophoretically using 4%–15% gradient polyacrylamide gels. RNase activity was dependent on the presence of a metal co-factor with significantly more activity with Zn²⁺ or Mn²⁺ than Mg²⁺. The RNases exhibited maximum activity at both pH 3.0 and pH 7.0 with no activity at pH 2.0 or 10.0. The optimal temperature for the iso-RNase was 70 °C. The molecular weight of the iso-RNase was determined to be 69 kDa using a Sephadex G-75 column.     

High-Performance Reversed-Phase Flash Chromatography Purification of Peptides and Chemically Modified Insulins

Preparative reversed-phase HPLC is the established method for the purification of peptides, but has significant limitations. We systematically investigated the use of high-performance reversed-phase flash chromatography (HPFC) to rapidly purify laboratory-scale quantities of crude, synthetic peptides and chemically modified insulins. We demonstrated these methods for a diverse set of peptides, including short, medium, and long peptides. Depending on the purity profile of the peptide, HPFC can be used either as the sole purification method, or as a pre-purification method prior to final HPLC purification. Furthermore, HPFC is suitable for the purification of peptides that are not fully in solution. We provide guidelines for the HPFC of synthetic peptides and small proteins, including the choice of columns, eluents, and gradients. We believe that HPFC is a valuable alternative to HPLC purification of peptides and small proteins.