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1.
在共培养体系中单克隆抗体AH6对小鼠胚泡着床的影响   总被引:6,自引:0,他引:6  
王晓琦  朱正美 《动物学报》1998,44(4):443-449
以单克隆抗体AH6「特异结合Le^Y寡糖,Fuca1-2Galβ1-4(F痉-3)GlcNAc-」以及其它3种与Le^Y寡糖结构近似的寡糖特异结构的单克隆抗体aLe^a、aLe^b和FE-A5为工具,采用小鼠体外着床模型。研究细胞表面Le^Y寡糖抗原与着床的关系及其在着床过程中具体作用环节。  相似文献   

2.
从石竹科植物多荚草(Polycarpon prostratum(Forssk.)Aschers.et Schwein.ex Aschers)中分离得到3个新的柴胡皂甙类化合物:prostratoside A ̄C(1 ̄3)。它们的结构通过波谱方法分别鉴定为:3-O-{β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-「β-D-glucopyranosy  相似文献   

3.
纯化的红花菜豆凝集素经肼解,Bio-GelP-2柱分离,得到的寡糖部份用硼氢化钠还原,再红Bio-Gel P-4柱层析,获得两条寡糖链。通过甲醇解,乙酰化反应,最后制成三甲基硅醚衍生物。气相色谱分析表面两个寡糖的组成为;Man8Xy1GlcNAc2和Man6XylGlcNa2Fuc。  相似文献   

4.
用HNMR法测定TDK肽在H2O(HODK),50%六氟丙醇(FPDK)和2mol/LGu.HCl(GUDK)溶液构象。在HODK和FPDK中,TDK肽的两段序列Asp0-Ile4,Ser9-Ili17分别具有较稳定的α-螺旋含量;而GUDK的SALS序列仍能检测到有序残存结构。并假设SALS序列是肽链形成二级结构的原始核心。  相似文献   

5.
细胞凋亡过程中bcl-2基因的甲基化   总被引:6,自引:0,他引:6  
为探讨凋亡过程中,bcl-2基因下调与该基因甲基化状态的关系,用5-氟尿嘧啶(5-Fu)诱导小鼠成纤维细胞NC3H10,TC3H10及人乳腺癌细胞MCF-7的凋亡,分别检测了这三种细胞凋亡过程中bcl-2的表达变化,与其调控区及编码区的甲基化状况.我们曾观察到5-Fu作用24~48h出现细胞存活率下降,DNA梯状断裂及细胞周期凋亡峰显现等典型凋亡现象.Northern杂交显示,在5-Fu作用12h时bcl-2mRNA水平已明显降低.由此,我们用小鼠bcl-2(mbcl-2)及人bcl-2(hbcl-2)基因调控区PCR扩增片段及bcl-2编码区(cDNA)片段作为探针,与5-Fu作用12h的细胞DNA的MspⅠ/HpaⅡ酶切产物进行Southern杂交,以未作用的细胞DNA同样酶切杂交为对照.通过杂交带谱的变化,分析bcl-2基因的甲基化状况.结果显示:mbcl-2及hbcl-2在5-Fu作用12h后调控区甲基化水平增高,但其编码区甲基化状态皆未出现可检出的变化.上述结果提示:bcl-2基因调控区甲基化水平升高可能与该基因下调有关  相似文献   

6.
用1HNMR法测定TDK肽在H2O(HODK),50%六氟丙醇(FPDK)和2mol/LGu·HCl(GUDK)中的溶液构象。在HODK和FPDK中,TDK肽的两段序列Asp0~Ile4,Ser9~Ile17分别具有较稳定的α-螺旋含量;而GUDK的SALS序列仍能检测到有序残存结构。并假设SALS序列是肽链形成二级结构的原始核心。  相似文献   

7.
动脉平滑肌细胞(sm ooth m uscle cell,SMC)是动脉粥样硬化(atherosclerosis,AS)斑块中的主要细胞,它的增殖在AS形成过程中极其重要.利用体外培养的人主动脉SMC,观察了天然高密度脂蛋白(native high density lipoprotein,N-HDL)及氧化修饰HDL(oxidized HDL,OX-HDL)对培养人主动脉SMC cyclin D1(细胞周期蛋白D1)基因转录表达的影响.结果表明:(1)N-HDL对SMCcyclin D1基因表达无影响(P> 0.05);(2)OX-HDL使SMCcyclin D1基因表达显著增强(P<0.01),其表达量随时间(2、12、24 h)延长而增加.上述结果表明,OX-HDL的致AS作用可能与其刺激SMCcyclin D1基因表达增加有关.  相似文献   

8.
人乳腺癌MCF-7细胞系凋亡过程中bcl-2基因的结合蛋白   总被引:1,自引:1,他引:0  
 M C F 7 是 p53 为野生型的人乳腺癌细胞系.为探讨该细胞系凋亡过程中 bcl 2 基因的下调机制,以 5 氟尿嘧啶(5 Fu)诱导凋亡,用 P C R 技术扩增出人 bcl 2(hbcl 2)基因调控区长度为 558bp 的片段,经亚克隆后的序列分析证实其准确性.用此 P C R 产物作为探针与 5 Fu 刺激 12 h 后的 M C F 7 核内蛋白质粗提物进行 Southw estern 印迹及凝胶阻滞( E M S A)分析.以未用 5 Fu 刺激者为对照.结果显示,细胞核内一分子量为 53 k D 的结合蛋白与 bcl 2 调控区的结合信号明显增强,而一种20 k D 的 D N A 结合蛋白与该区的结合信号明显减弱.这些结果提示p53 蛋白有可能是bcl 2 的负转录因子,20 k D 的 D N A 结合蛋白有可能是bcl 2 的正转录因子.  相似文献   

9.
用GC,IR,NMR,GC-MS及高碘酸氧化,Smith降解,甲基化分析,部分酸水解等方法确定了一个新的碱提水溶小皮伞多糖的一级结构:分子主链α-D-(1→2)Man,支链α-(1→4),α-(a→6)Glc,且均连在主链的0─6上。  相似文献   

10.
DDPH[1-(2.6-二甲基苯乙氧基)-2-(3.4二甲氧基苯乙胺基)丙烷盐酸盐]是南京药科大学合成的降压新化合物,也具有降低肺动脉高压和抑制肺动脉平滑肌细胞增殖作用。本实验用细胞培养、免疫细胞化学、图像分析、3H-TdR、细胞周期测定等方法,进一步探讨DDPH对缺氧性肺动脉平滑肌细胞(PASMCS)增殖的抑制机制。结果:缺氧促进肺动脉内皮细胞(PAECs)的PDGF·BB和bFGF两种生长因子的表达(积分光密度OD值)增高。缺氧内皮细胞条件培养液(HECCM)能促进PASMCS的PDGF·BB的OD值增高,bFGF的OD值无明显改变。加药组(HEC-CM+DDPH)的PDGF·BB和bFGF的OD值均显著降低,尤以PDGF·BB的OD值减少最多.提示:DDPH能抑制HECCM引起PASMCS的PDGF·BB和bFGF表达增多和细胞增殖。结果与大鼠实验观察相符。  相似文献   

11.
魔芋精粉经 β 甘露聚糖酶酶解成寡糖后 ,用活性炭柱进行分离纯化 ,以不同浓度 (5 % ,10 % ,2 0 % )的乙醇洗脱 .研究不同洗脱组分对链脲佐菌素 (STZ)诱导糖尿病模型的胰岛NO自由基释放量的影响 .发现 1mg ml以 5 %乙醇洗脱的寡糖可以使胰岛培养液中的NO自由基释放量平均下降2 5 4 % (P <0 0 5 ) ,0 1mg ml以 5 %乙醇洗脱的寡糖使NO自由基水平下降 2 0 % (P <0 0 5 ) .结果表明 ,5 %乙醇洗脱的魔芋寡糖对保护胰岛免受链脲佐菌素 (STZ)的破坏有一定的作用 .用凝胶色谱、红外光谱、元素分析、核磁共振光谱、质谱等方法初步分析了 5 %乙醇洗脱的魔芋寡糖的化学结构 .发现该糖是一种四糖 ,分子量为 6 6 6 .其推测性结构式为 :β D Man(1→ 4 ) β D Man(1→ 4 ) β D Glc(1→ 4 )α D Man ,β D Man(1→ 4 ) β D Glc(1→ 4 ) β D Man(1→ 4 )α D Man或 β D Glc(1→ 4 ) β D Man(1→4 ) β D Man(1→ 4 )α D Man .  相似文献   

12.
草苁蓉根、茎水溶性多糖BRT的结构特征   总被引:5,自引:0,他引:5  
本文以长白山区珍贵野生药用植物草苁蓉为研究对象 .草苁蓉又名“不老草” ,具有滋补强壮、益寿延年之功及补肾壮阳、润肠止血之效 ,为国家三级重点保护植物[1] .近年的研究发现 ,草苁蓉醇提物不仅可以清除体内的游离基 ,而且还可以显著增强机体的免疫能力 ,同时对草苁蓉化学成分的研究也在逐步深入[2 ] ,但对于草苁蓉多糖的系统研究尚未见报道 .为了更全面地认识和利用草苁蓉这一珍贵的植物资源 ,同时也为探讨多糖的结构与功能的关系 ,本文对草苁蓉根、茎的水溶性多糖BRT组分进行了结构测定方面的研究 .1 材料和方法1 1 材料为本研究…  相似文献   

13.
A xyloglucan was isolated from the 24% KOH extract of gobo (edible burdock, Arctium lappa L.). A methylation analysis and enzymic degradation studies on the polysaccharide showed that gobo-xyloglucan was built up predominantly of repeating-oligosaccharide units of hepta-(Glc: Xyl=4: 3), nona- (Glc: Xyl: Gal: Fuc=4: 3: 1: 1) and deca- (Glc: Xyl: Gal: Fuc=4: 3: 2: 1) saccharides in an approximate molar ratio of 14: 12: 5, which are the typical structural units of dicot xyloglucans.  相似文献   

14.
从刺五加果中抽提出水溶性粗多糖。经酸性乙醇分级及反复冻融得到多糖AS-2。AS-2经Sepharose CL-4B柱层析为单一对称峰,经醋酸纤维素膜电泳为一条带,冻融后高速离心无沉淀可证明其为均一级分。G.C分析表明,AS-2由Ara、Xyl、Rha、Gal、Glc组成,其单糖摩尔比为1.6:1.2:1.8:1.0:3.6。AS-2的分子量约为78kD,比旋光度[α]_D~(25)=+17°,特性粘度[η]=0.068。红外光谱分析含β型糖苷键。部分酸水解、酶解、高碘酸酸化、Smith降解、完全甲基化、G.C,G.C-M.S的分析结果表明,以β(1→3)Glc及β(1→4)Glc构成分子的主链。Glc的C_3上带有分支,约每4个己糖残基带有1个侧链。侧链上,Rha多以1→4苷键相连,部分残基C_2上有分支。Gal存在(1→6)及(1→3)连接方式,多数Glc以(1→6)苷键连结,少数Glc出现在分子非还原末端。位于分子末端的还有Ara与Xyl。  相似文献   

15.
We have recently discovered unusual sugar chains (xylose (Xyl)-glucose (Glc) and (Xyl)2-Glc) linked to a serine residue in the epidermal growth factor (EGF)-like domains of human and bovine clotting factors VII (Ser-52), IX (Ser-53), and protein Z (Ser-53), in addition to bovine platelet glycoprotein thrombospondin. We now have evidence of another modification in the first EGF-like domain of human factor IX, which proved to be a tetrasaccharide O-fucosidically linked to Ser-61. Two large peptides containing Ser-61 (positions 44-63), named hIX-GP1 and hIX-GP2, were first isolated from the lysyl endopeptidase-digest of human factor IX, by reversed-phase high performance liquid chromatography (HPLC). Data on the component sugar analysis after pyridylamination (PA) and sialic acid analysis of the isolated peptides indicated that they contained 1 mol each of galactose (Gal), fucose (Fuc), N-acetylglucosamine (GlcNAc), and N-acetylneuraminic acid (NeuAc), in addition to Glc and Xyl. hIX-GP1 was further digested with asparaginyl endopeptidase, and two glycopeptides containing Ser-61, named N-3 (positions 59-63) and N-9 (positions 55-63), were isolated, respectively. These glycopeptides were both composed of 1 mol each of Gal, Fuc, GlcNAc, and NeuAc but did not contain Xyl and Glc. Moreover, the data on beta-elimination for N-9 and of the fast atom bombardment mass spectrometric analysis on peptide N-3 suggested the presence of a tetrasaccharide linked to Ser-61. An analysis of the PA-oligosaccharide released from hIX-GP1 by hydrazinolysis followed by pyridylamination revealed that the reducing end was PA-Fuc. All the results support the proposal that human factor IX has a novel tetrasaccharide consisting of 1 mol each of Gal, Fuc, GlcNAc, and NeuAc, which is O-glycosidically linked to Ser-61 through the Fuc residue.  相似文献   

16.
对小刺猴头过滤掉发酵液的发酵菌丝体,水提和碱提后获得的均一组分多糖HMP-w1.1和HMP-a1.1进行结构性质的研究。结果表明:HMP-w1.1是分子量为36.3 kD的α型吡喃糖,单糖组成为甘露糖(Man),葡萄糖(Glc),半乳糖(Gal),岩藻糖(Fuc);HMP-a1.1是分子量为42.8 kD的β型吡喃糖,单糖组成为甘露糖(Man),半乳糖醛酸(GalUA),葡萄糖(Glc),半乳糖(Gal),岩藻糖(Fuc)。综合高碘酸氧化和Smith降解的试验结果,推断HMP-w1.1的糖苷键构型可能为1→、1→4、1→4,6、1→6、1→2、1→2,6;HMP-a1.1的糖苷键构型可能为1→6、1→2、1→2,6。  相似文献   

17.
Blood group H antigen with globo-series structure, reacting with the monoclonal antibody MBrl, was isolated and characterized from human blood group O erythrocytes. The structure was identified by methylation analysis, direct probe mass spectrometry, and 1H-nuclear magnetic resonance spectroscopy as shown below: Fucαl → 2Galβl → 3GalNAcβl → 3Galαl → 4Galβl → 4Glcβl → 1Cer  相似文献   

18.
Four different H-type 1 (LedH) blood-group-active glycosphingolipids (LedH-I–IV) have been isolated from the plasma of blood-group O Le(a?b?) secretors. The agglutination of O Le(a?b?) erythrocytes from secretors by 50 μl of 4 hemagglutinating units of caprine anti-LedH (anti-H-type 1) serum was inhibited by 0.02 μg of each of all four glycolipids. No Lea or Leb activities or reaction against Ulex europaeus lectin could be found. LedH-I, -II, -III, and -IV at 0.05, 0.01, 0.01, and 0.02 μg each are sufficient for incubation in order to convert 9 × 107 O Le(a?b?) erythrocytes from nonsecretors into H-type 1 (LedH)-positive cells. Structural analysis of the H-type 1 glycolipids was performed in comparison to that of Lea- and Leb-blood-group-active glycolipids from human plasma isolated previously: Gas chromatography of peracetylated alditols revealed sugar composition. Combined gas chromatography-mass spectrometry established the glycosidic linkages. Together with the results obtained by direct inlet mass spectrometry of permethylated glycosphingolipids and by 360-MHz 1H nuclear magnetic resonance spectroscopy (Egge, H., and Hanfland, P., 1981, Arch. Biochem. Biophys., 210, 396–404; Dabrowski, J., Hanfland, P., Egge, H., and Dabrowski, U., 1981, Arch. Biochem. Biophys., 210, 405–411) the complete structures of the oligosaccharide chains of the Lea-, Leb-, and H-type 1-active glycolipids were established: Galβ1 → 3GlcNAc(4 ← 1αFuc)β1 → 3Galβ1 → 4Glcβ1 → 1 Cer for the Lea antigens; Fucα1 → 2Galβ1 → 3GlcNAc(4 ← 1αFuc)β1 → 3Galβ1 → 4Glcβ1 → 1 Cer for the Leb antigens; and Fucα1 → 2Galβ1 → 3GlcNAcβ1 → 3Galβ1 → 4Glcβ1 → 1 Cer for the H-type 1 (LedH) glycolipids. The diverse antigens of the same blood-group specificity obviously differ from one another in their lipid residue. In addition, plasmatic neolactotetraosylceramide could be identified, differing from that of human erythrocytes by a slower migration behavior in thin-layer chromatography.  相似文献   

19.
The polymers secreted by suspension-cultured apple cells were composed of 85% carbohydrate (76% neutral sugar and 9% uronic acid) and 15% w/w protein. The extracellular polysaccharides (ECPs) contain 23% XG and 59% AGPs. The monosaccharide composition of the ECPs consisted of Gal, Ara, Glc and Xyl, with smaller amounts of Rha, Fuc and Man. Fractionation of the ECPs by anion-exchange chromatography yielded an unbound neutral fraction and a bound acidic fraction. Monosaccharide and linkage compositions of each fraction were determined. The neutral fraction (48% recovered carbohydrate) was composed of xyloglucan (XG; >90 mol%) which was purified by selective precipitation with Fehling’s solution to yield pure XG. The purified XG had a Glc:Xyl:Gal:Fuc ratio of 4.0:2.5:0.8:0.5; the XG was not O-acetylated. The structure of the secreted XG was similar to that extracted from apple-pomace. The acidic fraction (52% recovered carbohydrate) was composed primarily of arabinogalactan-proteins (AGPs) as detected by the β-glucosyl Yariv diffusion test. The AGP had a Gal:Ara ratio of 1.3: 1.0. Minor amounts of arabinan, xylan and mannan were also detected in the ECPs. This study is the first examination of the polysaccharides secreted by apple cells grown in suspension culture.  相似文献   

20.
Apple cell walls or alkali-extracted xyloglucans were digested with an endo-glucanase from Trichoderma viride and the resulting oligosaccharides were isolated by chromatography on Bio-Gel P-4. Three main oligosaccharides were present in similar proportions, and their structures were shown to be [Xyl(Glc)]3-Glc, [Xyl(Glc)]2-(FucGalXyl)Glc-Glc, and XylGlc-(GalXyP)Glc-(FucGalXyl)Glc-Glc. Each non-reducing-end Glc was 6-linked, each reducing-end Glc was 4-substituted, and each other Glc was 4,6-disubstituted. The Xyl was either terminal or 2-substituted, the Fuc was terminal, and the Gal was either terminal or 2-substituted. The 1H-NMR spectra of the oligosaccharides extracted directly from the cell wall showed that they are not acetylated. Other oligosaccharides, notably GalXyl3Glc4, Xyl2Glc4, and Xyl2Glc3, were present in smaller proportions in the digest of the cell walls.  相似文献   

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