17400鲨鱼软骨血管生成抑制因子的纯化及生物学活性研究

采用盐酸胍抽提、膜超滤、丙酮分级沉淀、Sephadex-75柱层析和C₄反相高效液相色谱等分离步骤,从广东阳江鲨鱼软骨中纯化获得新的鲨鱼软骨血管生成抑制因子SCAI-c(SharkCartilageAngiogenesis In-hibitor-c,SCAI-c);SDS-PAGE电泳银染显示为一条带,根据蛋白质的相对迁移率计算,分子量为17400;它对鸡胚绒毛尿囊膜血管的形成具有显著抑制效应,并有明显的浓度依赖关系.SCAI-c与SCAI-a具有类似的生物学特征.     

鲨鱼软骨血管抑制因子的高效液相色谱与电喷雾质谱研究

电喷雾质谱 ( ESIMS)具有快速、灵敏等特点 ,近年来已成为鉴定和分析多肽、蛋白质和核酸的有力工具 .将 ESIMS与高效液相色谱 ( HPLC)联用 ,在蛋白质分子量、结构及活性位点等方面的研究已取得较大的进展 [1 ] .鲨鱼软骨血管抑制因子 ( SCAIF- I)是作者之一从鲨鱼软骨中提取的一种未知蛋白质[2 ] ,研究表明 ,SCAIF- I对肿瘤、癌症的抑制及治疗具有明显的疗效[3] .因此 ,对其结构的研究具有重要的意义 .本文报道了用 HPL C与 ESIMS对未知蛋白质 SCAIF- I的分子量及肽段部分序列的测定结果 .1　实验部分1 .1　样品制备　 SC…     

苦瓜素的分离纯化与抗肿瘤活性的研究

本文报道了α－苦瓜素和β苦瓜素分离纯化的工艺改进,测定了两种苦瓜素的理化性质。实验证明,两种苦瓜素对小鼠Ｓ－１８０实体瘤均具有显著的抑制作用,抑瘤率分别为７１．２％和６８．６％;两种苦瓜素对人胃癌ＮＫＭ细胞株的ＤＮＡ,ＲＮＡ和蛋白质的合成亦均具有明显的抑制作用。     

两步柱色谱法分离纯化重组肿瘤血管生长抑制因子Kringle 5

建立了一种用Ni2+螯合的Chelating Sepharose Fast Flow亲和柱色谱和Sephadex G-75凝胶排阻柱色谱分离纯化重组肿瘤血管生长抑制因子Kringle 5的方法。采用该工艺得到的重组Kringle 5经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析表明其纯度约为98%,且具有抑制鸡胚绒毛尿囊膜新生血管生成的生物活性。     

磁性粒子在蛋白质分离纯化中的应用

磁性粒子与磁性分离技术结合用于生物分子和生物微粒的分离近年来受到了广泛关注。磁性粒子经过适当的表面修饰,可高度选择性地结合目标蛋白,在解决蛋白质的快速分离及高特异性的选择性分离方面具有优势。随着蛋白质组学研究的发展,磁性粒子用于蛋白质分离纯化的研究日渐增多。本文介绍了磁性粒子和磁性分离的基本特点,综述了近5年国内外有关磁性粒子在蛋白质分离纯化中的应用和发展现状。     

蛋白蛋分离与纯化过程中高效离子交换色谱柱的再生

高效离子交换色谱法分离和纯化蛋白质时,蛋白质在色谱柱上的不可逆吸附使柱效降低,柱压升高。本文使用2％的胰蛋白酶溶液在37℃下处理TSKgelCM-5PW和TSKgelDEAE-5PW（7×7．5mmI.D.）离子交换色谱柱24h后,柱压显著降低,柱效提高4~13倍,交换容量也得到恢复。离子交换色谱柱的恢复程度和交换容量与处理液的用量有关。     

紫杉醇的分离纯化及其检测

综述了紫杉醇的分离纯化及其检测方法。     

干苔多糖的分离纯化及抗肿瘤活性研究

干苔经冷水，热水，热酸水三步提取多糖。配位吸附动力学研究表明，与钙型，铝型树脂相比，铜型树脂对干苔多糖吸附最快，吸附量最多。pH值配位沉淀反应研究进一步显示干苔多糖与Cu^2 的沉淀能力比Al^3 好。采用三种pH值铜盐络合沉淀，得到初步提纯五种多糖（冷提糖Ⅰ，热提糖Ⅱ、Ⅲ酸糖Ⅳ、Ⅴ），用离子交换（静态，动态）法除去铜离子，得到纯度为98．4％的干苔多糖，回收率达97．8％。离子条件下，几种多糖在对人胰腺癌SW1990细胞的无血清培养中，热提糖Ⅲ表现出较好的抑制活性。该多糖还与固定化藻蓝蛋白表现出一定协同抑制肿瘤细胞生长的作用。红外光谱分析证明热水抽提多糖Ⅲ是一种酸性多糖。     

苦瓜子蛋白的分离纯化及其性质研究

从苦瓜种子的粗提物苦瓜子蛋白丙酮分级沉淀干粉中,用CM-SephadexC-50和SephadexG-75分离得到了两个核糖体失活蛋白,α-苦瓜子蛋白(α-momorcharin,α-MMC)和β-苦瓜子蛋白(β-momorcharin,β-MMC),其等电点分别为9.10(α-MMC),9.32(β-MMC)。用ESI-MS和MALDI-TOF-MS测定它们的分子量,分别为28625(α-MMC),29076(β-MMC)(+Na,29099);28795(α-MMC),29074.7(β-MMC)。它们都是糖蛋白。其生物活性的分析测定表明,都属于RNAN-糖苷酶。本文重点对β-苦瓜子蛋白的分离纯化及其性质进行详细报道,并对其N-端部分的氨基酸顺序进行了测定。     

糖蛋白激素的不均一致及其色谱分离纯化研究的进展

本文介绍了糖蛋白激素的不均一性，讨论了影响其色谱分离纯化过程的各种因素，以及色谱分离模式与操作模式的选择。     

Isolation,Purification and Bioactivities of Polysaccharides from Irpex lacteus

Irpex lacteus has been widely used for treating chronic glomerulonephritis as a traditional Chinese medicine.Seven water-soluble polysaccharide fractions(ILN Ⅰ,ILN Ⅱ,ILN Ⅲ,ILA Ⅰ,ILA Ⅱ,ILB Ⅰ and ILB Ⅱ)w...     

微波消解衍生化气相色谱-质谱法测定鲨鱼软骨中的脂肪酸

 研究了用微波技术消解衍生化气相色谱 质谱法 (GC MS)快速测定鲨鱼软骨中脂肪酸的分析方法。用正交设计试验优化消解衍生化条件 ,以盐酸 甲醇 (体积比为 1∶4)体系作消解衍生化溶液 ,在 60 0W微波功率作用下加热 4min进行样品的前处理 ,将样品的消解、脂肪酸的衍生化及脂肪酸甲酯的萃取融于一体。方法具有灵敏度高、省时、省试剂、操作方便等特点。该法适用于大批量固体样品中脂肪酸的测定。     

Chitin- and Streptavidin-Mediated Affinity Purification Systems: A Screening Platform for Enzyme Discovery

Affinity purification of recombinant proteins is an essential technique in biotechnology. However, current affinity purification methods are very cost-intensive, and this imposes limits on versatile use of affinity purification for obtaining purified proteins for a variety of applications. To overcome this problem, we developed a new affinity purification system which we call CSAP (chitin- and streptavidin-mediated affinity purification) for low-cost purification of Strep-tag II fusion proteins. The CSAP system is designed to utilize commercially available chitin powder as a chromatography matrix, thereby significantly improving the cost-efficiency of protein affinity purification. We investigated the CSAP system for protein screening in 96-well format as a demonstration. Through the screening of 96 types of purified hemoproteins, several proteins capable of the catalytic diastereodivergent synthesis of cyclopropanes were identified as candidates for an abiotic carbene transfer reaction.     

5-阿维菌素B1a酯的合成及生物活性

阿维菌素B_1a(AVB_1a)与羧酸在DMAP/DCC体系中直接酯化,得到10个5-AVB_1a酯衍生物,产率50%～79%;其化学结构由IR,¹H NMR,¹³CNMR和MS谱确证.生物活性测定结果表明,部分5-阿维菌素B_1a酯衍生物具有良好的杀虫、杀螨活性.     

Toward a Constitutive Law of Cartilage: A Polymer Physics Perspective

To describe load bearing and lubrication of cartilage requires treating its collagen network and proteoglycan (PG) phases separately in a constitutive law of the tissue. We propose a framework for developing such an empirical constitutive law that treats the cartilage extracellular matrix (ECM) as a composite medium, with a PG phase that exerts a swelling pressure, and a collagen network phase that restrains it. We compare and contrast this model to a biomechanical constitutive law that aggregates the collagen and PG phases into a single “solid-like” elastic tissue matrix, and show that aggregation obscures essential differences in the physical-chemical properties of the collagen and PG constituents as well as their distinct biological roles within cartilage's ECM. We also relate moduli in the aggregate constitutive model to quantities measured in an osmotic stress titration experiment.     

Syntheses and Bioactivity of 4"-Sulfonate-5-triphenylsilyl Avermectin B1a and Ivermectin B1a Derivatives

Fourteen new derivatives of avermectin B1a and ivermectin B1a were synthesized from C5-O-triphenylsilyl avermectin B1a and ivermectin B1a(yield from 40% to 83%). Their chemical structures were characterized by means of IR, 1H NMR, 13C NMR and FAB-MS spectrometries. Some of them show excellent insecticidal activity.     

Solubilization and Refolding with Simultaneous Purification of Recombinant Human Stem Cell Factor

Recombinant human stem cell factor (rhSCF) was solubilized and renatured from inclusion bodies expressed in Escherichia coli. The effect of both pH and urea on the solubilization of rhSCF inclusion bodies was investigated; the results indicate that the solubilization of rhSCF inclusion bodies was significantly influenced by the pH of the solution employed, and low concentration of urea can drastically improve the solubilization of rhSCF when solubilized by high pH solution. The solubilized rhSCF can be easily refolded with simultaneous purification by ion exchange chromatography (IEC), with a specific activity of 7.8 × 10⁵ IU·mg⁻¹, a purity of 96.3%, and a mass recovery of 43.0%. The presented experimental results show that rhSCF solubilized by high pH solution containing low concentration of urea is easier to be renatured than that solubilized by high concentration of urea, and the IEC refolding method was more efficient than dilution refolding and dialysis refolding for rhSCF. It may have a great potential for large-scale production of rhSCF.     

Syntheses and Bioactivity of 4＂-Sulfonate-5-triphenyl silyl Avermectin B1a and Ivermectin B1a Derivatives

Fourteen new derivatives of avermectin B1a, and ivermectin B1a were synthesized from C5-O-triphenyl silylavermectin B1a and ivermectin B1a (yield from 40% to 83%). Their chemical structures were characterized by means of IR. ^1H NMR, ^13C NMR and FAB-MS spectrometries. Some of them show excellent insecticidal activity.