枸杞子糖蛋白的分离纯化,物化性质及糖肽键特征

从宁夏枸杞子提取得到的粗多糖,经ＤＥＡＥ－Ｃｅｌｌｕｌｏｓｅ和ＳｅｐｈａｄｅｘＧ－１００柱层析,得到均一的枸杞子糖蛋白ＬｂＧＰ。分子量由ＳＤＳ－ＰＡＧＥ测定为８８ｋｄ,糖含量为７０％,糖组成为Ａｒａ：Ｇａｌ：Ｇｌｃ＝２．５：１．０：１．０,并含有其他１８种天然氨基酸。初步分析表明ＬｂＧＰ是Ｏ－连接的糖蛋白。     

枸杞子糖蛋白一条高分子量糖链的结构测定

采用碱解法分离枸杞子糖蛋白中的糖链,得到一条分子量达４０ｋｄ的糖链。由等量的Ａｒａ和Ｇａｌ组成。甲基化、部分酸水解及ＮＭＲ技术确定了其主要结构特征。     

牡蛎中糖蛋白成分的分离纯化及其性质研究

本文以青岛产牡蛎为原料,通过低温水提取工艺得到牡蛎糖蛋白粗提物,然后用凝胶柱层析(Sephacryls-100 HR)进行纯化,最后用高效液相色谱制备得到纯度较高的物质F22.由SDS-聚丙烯酰胺凝胶电泳证实F22是纯度较高的单一组分;分子量为34.2 kDa;等电聚焦的结果显示等电点为5.5;红外色谱呈现出典型的糖的特征吸收峰;气相色谱分析结果显示F22的中性单糖是由葡萄糖这一种单糖组成的同多糖;β-消去反应表明F22的糖肽键应为N-型糖苷键.     

虫花菌胞外糖蛋白的分离、纯化及其性质研究

虫花菌(Isaria farinosa(Dicks)Fr.)发酵液经超滤浓缩、乙醇沉淀、弱酸性阳离子交换树脂和弱碱性阴离子交换树脂去杂蛋白后,又经Sephadex G-150纯化得到PG。PG经醋酸纤维膜电泳、聚丙烯酰胺凝胶电泳和Sepharose 4B柱层析,证明是单一均匀的糖蛋白。PG的分子量为11.1万。PG的糖含量为92.35％、蛋白含量为7.61％。PG用气相色谱、红外光谱分析表明含有D-甘露糖、D-半乳糖,其摩尔比是5.93:1。推测PG主要含α-型糖苷键。PG对小鼠实体瘤S-180有一定的抑制作用,抑瘤率为22.2％。     

建宁莲子糖蛋白的分离、纯化及清除自由基作用

从红花建莲(Nelumbo nucifera Gacrtn.Fujian)的莲子中提取出具有生物活性的糖蛋白(GLP),并进行清除自由基作用的研究。用60％(NH^4)2SO4饱和溶液沉淀蛋白质,经ConA-Sepharose 4B亲和层析校分离,SephadexG-150凝胶层析校纯化,得到2个组分的糖蛋白,分子量分别为25kD的GLP-I和92．5kD的GLP—E,后者为其主要成分。GLP中蛋白质含量是58．8％,总糖含量是36．4％。TLC和GC分析结果：GLP—I是由L—鼠李糖,D—木糖,D—甘露糖和D—葡萄糖组成。其中性糖摩尔比：1．08：0．92：2．54：4．15。GLP—E是由L—鼠李糖D—木糖,D—甘露糖,L—阿拉伯糖,D—半乳糖,D—葡萄糖和D—葡萄糖醛酸组成,其中性糖摩尔比：1．25：1．03：2．85：0．94：3．1634．65。药理实验表明：两种糖蛋白均有清除自由基的作用,而GLP—Ⅱ清除能力大于GLP—I。     

VLC法分离纯化枸杞子中类胡萝卜素的研究

采用真空液相色谱（VLC）法,快速、简易、高效地分离、纯化了枸杞子中类胡萝卜素及其脂肪酸酯;采用薄层色谱法,对比了氧化镁和硅胶两种吸附剂的分离、纯化效果。结果表明,依次用氧化镁和硅胶为吸附剂进行的两次真空柱色谱分离,可有效去除脂溶性杂质并分离类胡萝卜素各组分,是类胡萝卜素分离、纯化的可靠方法。     

小球藻糖蛋白的分离、纯化和结构分析

采用柱层析分离纯化小球藻糖蛋白,并对其进行结构分析。结果表明,小球藻糖蛋白为白色粉末,产率为鲜藻的0．28％,易溶于水,分子量约为65,000Da,属O-连接方式,蛋白质含量为12．01％,糖链部分含有岩藻糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖。     

山茱萸糖蛋白的纯化及部分理化性质研究

α-淀粉酶抑制剂广泛存在于高等植物中,能抑制糖类在消化道内的吸收,是一种潜在的治疗糖尿病、肥胖和高血脂的药物。本文采用D101大孔吸附树脂,从山茱萸干果中提取得到粗提物,再经SP Sepharose和Sephacryl S-300柱层析,得到一种具有抑制α-淀粉酶活性的糖蛋白(CoGP)。Sephacryl S-300柱层析,PAGE电泳均证明该糖蛋白为单一组分;在还原条件下的SDS-PAGE电泳中呈现两条蛋白带,其分子量分别是62．O kD和56．8kD,利用Sephaeryl S-300柱层析测定表观分子量为158,9kD,表明CoGP由两个亚基组成;利用苯酚-硫酸法测得其糖含量约为51％;在α-淀粉酶的抑制实验中,山茱萸糖蛋白表现出反竞争的抑制特性。     

夏枯草多糖分离纯化、相关性质及药效

研究了夏枯草多糖的提取工艺、分离纯化、部分理化性质以及夏枯草多糖的免疫学活性。夏枯草经水提醇沉,去蛋白、脱色、凝胶柱色谱等步骤分离纯化得到夏枯草精多糖（Pure polysaccahrides of Spica prunellae,PPSP）。HPGPC法测其相对分子质量,红外光谱法对其结构进行初步分析,柱前对氨基苯甲酸衍生化HPLC法测其单糖组成。免疫学实验证明夏枯草精多糖单独作用或协同ConA均可显著促进小鼠脾淋巴细胞增殖,夏枯草精多糖在200μg／mL质量浓度下对正常小鼠的廓清指数和吞噬指数有明显促进作用。     

虫花菌胞外糖蛋白的分离,纯化及其性质研究

虫花菌发酵液经超滤浓缩、乙醇沉淀、弱酸性阳离子交换树脂和弱碱性阴离子交换树脂去杂蛋白后,又经Ｓｅｐｈａｄｅｘ Ｇ－１５０纯化得到ＰＧ。ＰＧ经醋酸纤维膜电泳、聚丙烯酰胺凝胶电泳和Ｓｅｐｈａｒｏｓｅ ４Ｂ柱层析,证明是单一均匀的糖蛋白。ＰＧ的分子量为１１．１万。ＰＧ的糖含量为９２．３５％,蛋白含量为７．６１％。ＰＧ用气相色谱、红外光谱分析表明含有Ｄ－甘露糖、Ｄ－半乳糖,其摩尔比是５．９３：１。推测ＰＧ     

一株芽孢杆菌胞外多糖的分离纯化及其抗氧化性测定

基于实验室从新疆罗布泊沙漠筛选到一株芽孢杆菌, 研究了该菌胞外多糖的分离纯化工艺及其抗氧化性质。发酵液经离心, 抽滤等预处理后, 使用Sevag试剂除蛋白, 并以无水乙醇作提取溶剂, 通过正交实验确定最佳提取条件为: pH为7.0, 温度为4°C, 时间为1.5 h, 料液比为1:4。粗多糖溶解后上活性炭柱(1.5 cm ′ 24 cm), 用蒸馏水、60%乙醇及95%乙醇洗脱, 分离得到主要部分, 再经Sephadex G-100凝胶柱, 用0.2 mol/L的NaCl溶液洗脱, 硫酸苯酚法和考马斯亮蓝     

Study on the Isolation,Purification and Antioxidation Properties of Polysaccharides from Spirulina maxima

The emde polysaccharide was extracted from Spirulina maxima with hot water, and precipitated by ethanol after depmteinization. Two portions of refined polysaccharides (SPS I and SPS H ) were prepared after further purification on DEAE-Sephadex A-25 column chromatography, and their homogeneity was examined with Sephadex G-150 column chromatography. The ultraviolet spectm showed their characteristic absorption at 195.00 mn. In order to estimate the antioxidation activity of SPS Ⅰ and SPS Ⅱ, three systems of generating superoxide radical (O2-), lipid radical (R') and hydroxyl radical (OH') respectively in vitro were designed. The results showed that both SPS Ⅰ and SPS Ⅱ from S. maxima had significant capacity of scavenging OH' ( P < 0.05), but no effect on O2 ( P > 0.1 ); and that SPS Ⅰ could scavenge R' under lower concentration of polysaccharides (P < 0.05), while the capacity of scavenging R' of both SPS Ⅰ and SPS Ⅱ decreased in higher concentration ( P > 0.2). These results demonstrated that the significant antioxidation activity of polysaccharides from S. maxima was focused on scavenging OH', the most highly reactive one of the oxygen radicals.     

枸杞多糖的提取纯化及组成分析

采用水提法从枸杞中提取分离枸杞多糖(LBP)用DEAE纤维素柱色谱和凝胶柱色谱进行分离纯化,采用GPC-LLS法、红外光谱和气相色谱等方法对其组成进行研究。结果表明LBP含有3个级分,LBP的分子质量约为1.497×105,由阿拉伯糖(Ara),鼠李糖(Rha),木糖(Xyl),甘露糖(Man),半乳糖(Gal)和葡萄糖(Glc)6种中性单糖组成。     

枸杞多糖LBP－I的分离纯化及性质鉴定

枸杞多糖ＬＢＰ－Ｉ的分离纯化及性质鉴定何进梁运祥张声华（华中农业大学生命科学技术学院,武汉４３００７０）（华中农业大学食品科学技术系）Ｉｓｏｌａｔｉｏｎ,ｐｕｒｉｆｉｃａｔｉｏｎａｎｄｐｒｏｐｅｒｔｙｉｄｅｎｔｉｆｉｃａｔｉｏｎｏｆｐｏｌｙｓａｃｃｈ...     

Purification and Characterization of Cotton Lectin

Defatted seeds of wilt-disease resistant were extracted overnight with PBS at 4 ℃. After centrifugation. 90% saturated (NH4)2SO4 was added to the supernatant. The precipitates were dialysed against H2O, then lyophilized. The purified lectin was obtained by DEAE-cellulose ion-exchange chromatography, Sephadex G-100 filtration, and Sepharose 4B-Hog thyroglohulin affinity chromatography. The activity of the lectin was tested with fresh rabbit erythrocyte in each step of the procedure, and the active part was collected. This sample demonstrated single band on PAGE, SDS-PAGE and HPLC. The lectin was a glycoprotein. It contained 1.5% of neutral saccharide and its molecular weight was 63000 determined by Sephadex G-100 filtration. The N-terminal amino acid of the lectin was Val. The lectin showed no specific agglutination with any type of human erythrocytes. The hemagglutinaition activity could be inhibited by galactose and hog thyroglobilin, and depended on Ca2+, Mn2+, especially on Ca2+, not Mg2+. Its biological activity lost at 65 ℃ for S min. This lectin is used as a mitogen for human peripheral blood lymphocytes.     

去糖人绒膜促性腺激素的制备及其性质鉴定

 人绒膜促性腺激素(hCG)是一种糖蛋白,我们用Sephadex G-100和SE-Se-phadex C-50二步柱层析从人尿hCG粗品纯化了hCG,样品经三氟甲烷磺酸(TFMS)处理,得到在非还原条件下SDS-PAGE单带纯的DG-hCG。初步研究表明DG-hCG与天然hCG具有相似的圆二色性谱,但它们体内的代谢清除率完全不同。     

宁夏枸杞果实糖积累和蔗糖代谢相关酶活性的关系

通过对枸杞果实发育过程中果实生长模式、蔗糖、果糖、葡萄糖和淀粉含量及糖代谢相关酶活性的测定,研究了宁夏枸杞果实生长发育过程中糖的代谢积累与相关酶活性的关系.结果表明:(1)宁夏枸杞果实发育呈双S"曲线,果实主要以积累己糖为主.(2)蔗糖磷酸合成酶(SPS)活性在果实发育初期处于下降的趋势,在花后19d开始上升,果实转色后又逐渐下降;蔗糖合成酶(SS)活性总体表现为SS分解方向的活性大于SS合成方向的活性,说明枸杞果实发育过程中,SS的活性主要以分解方向的为主;酸性转化酶(AI)和中性转化酶(NI)的活性随果实发育呈上升趋势,但在果实成熟后期有所下降,且AI和NI活性高于合成酶类的活性,较高的转化酶类活性促进了果实内部己糖的积累.(3)在枸杞果实生长发育中,葡萄糖和果糖含量与AI和NI均呈极显著正相关,而与其它酶不具有相关性.说明AI和NI在宁夏枸杞果实的糖代谢中起着主要的调控作用.     

Isolation,Purification, and Characterization of the Oligomeric Seed Globulin from Amaranthus hypochondriacus

The main storage seed protein of Amaranthus hypochondriacus, the oligomeric salt-soluble globulin, was isolated and purified to homogeneity by Sephacryl S-300 gel filtration and Separon Hema-Bio 1000 DEAE anion-exchange chromatography. The globulin had two heterogeneous forms, a major and minor species with apparent molecular masses of 398,000 and 337,000 daltons, respectively. Each of the two species were analyzed by sodium-dodecyl-sulfate polyacrylamide gel electrophoresis (PAGE) and by native-PAGE (without prior reduction of disulfide bonds). Only slight differences were observed in their subunit patterns although appreciable differences in mobility and dissociation behaviour were noted on native-PAGE. The major protein fraction was oligomeric, consisting of a tetrameric and hexameric moiety held together by weak secondary forces. The minor fraction, a hexamer of slightly higher apparent molecular mass was a polymeric species derived in part from a sulfhydryl-disulfide interchange reaction.