pH-potentiometric study on rare earths and calcium binary and ternary complexes with DL-malic acid and L-hydroxyproline

The stability constants of M-L binary system and M-L-L' (M = La3+ similar to Yb3+, Y3+ and Ca2+; L= DL-malic aicd, L' = L-hydroxyproline) ternary system were determined by pH-(0)-tentiometric method under the simulating physiological condition(37 degrees C, I=0.15 mol/L NaCl). The complex species MpLqLr'H-s(abbr as pqrs) in the sytems were ascertained by program COMPLEX. The results show that there are three species(1101, 1100 and 1200) in M-L binary system and one species(1010) in M-L' binary system. In addition to the above four species, a new species, 1112 was found in the M-L-L' ternary system, which is the only species of mixed ligands. Rare earth ions form more stable complexes than calcium ion does and the stability differences between their complexes in the ternary system are less than that in the binary system. The distributions of all the species in La-L-L' ternary system vs pH are discussed.

Studies on the coordination of lanthanide with L-hydroxyproline and DL-citrulline

The stability constants of binary and ternary complexes of lanthanide with L-hydroxyproline and DL-citrulline were obtained by using potentiometric titration under the physiological condition(37 degrees C, 0.15 mol/L NaCl). The coordination of lanthanide with the two ligands was discussed.

植物细胞壁富含羟脯氨酸糖蛋白生化特性及基因克隆的研究

植物细胞壁富含羟脯氨酸糖蛋白生化特性及基因克隆的研究分成三部分： 第一部分，首先从胡萝卜愈伤组织的细胞壁中获得0.2M氯气钙可溶性蛋白质组分, 经10% TCA沉淀及羧甲基纤维素层析，分离得到一个伸展蛋白，并以SDS-聚丙烯酰胺凝胶电泳，氨基酸组成分析，分子电镜观察对所得的伸展蛋白进行了鉴定，结果表明，在胡萝卜愈伤组织中只存在一种伸展蛋白;SDS-聚丙烯酰胺凝胶电泳的考马斯蓝染色和PAS反应均为阳性，表明伸展蛋白除蛋白质组分还含有糖基;氨基酸组成分析表明，羟脯氨酸的克分子含量约占全部氨基酸的40%，丝氨酸的克分子含量约为羟脯氨酸的四分之一，含有大量的碱性和中性氨基酸，而只含有非常少量的酸性氨基酸，并且这些氨基酸克分子百分数也接近于胡萝卜富含羟脯氨酸糖蚤白基因推测出的克分子百分数。这些结果表明已经得到了一个电泳纯的伸展蛋白。伸展蛋白分子电镜观察证明它是一个棒状分子，长度为87纳米。 第二部分，用得到的伸展蛋白免疫家兔和大鼠，得到的抗体的免疫双扩散效价分别为1:2和1:1，用酶联免疫吸附分析测定的兔抗体效价为1:12，800，同时还建立了竞争性酶联免疫吸附分析测定伸展蛋白含量的标准曲线，线性范围为10-0.00001微克。利用得到的抗体对大豆下胚轴伸展蛋白的合成进行了研究。免疫荧光定位表明，大豆下胚轴表皮细胞及表皮下几层薄壁细胞有大量的荧光标记，并且这些荧光标记大部分分布在细胞质内。大豆下胚轴O.lM Tris-HCl pH7.4和0.2M氯化钙的提取物Western Blotting分析证明0.2M氯化钙提取物有与胡萝卜伸展蛋白电流性质相似的组分，并且这个组分在真菌诱导物处理的大豆下胚轴中的积累明显高于受伤处理的下胚轴。受伤和真菌诱导物处理大豆下胚轴中伸展蛋白积累的变化已经用Western Blotting分析和斑点酶联免疫吸附分析来观察，发现真菌诱导物处理的对灰斑病抗性的大豆下胚轴能够较快地积累伸展蛋白（24 - 48小时），而敏感品系的大豆下胚轴则合成伸展蛋白较晚（43-72小时）。在观察大豆下胚轴免疫荧光定位也发现类似的结果。对伸展蛋白基因的转录活性的初步研究认为抗性品系的大豆下胚轴同源mRNA转录可能早于24小时，而敏感品系大豆下胚轴同源mRNA转录可能在24小时后。以上结果认为大豆下胚轴含同源的mRNA和蛋白质组分，因此推测大豆基因组DNA有伸展蛋白基因。 第三部分，根据第二部分得到的结果，用已经得到的编码胡萝卜伸展蛋白的基因（克隆于pUC8质粒载体中）作探针，与大豆基因组DNA的EcoRI部分酶解片段杂交寻找大豆伸展蛋白基因，已经发现四个片段与探针DNA有同源性。它们的分子量分别约为23kb，8kb，5kb和2.8kb，并且23kb片段可能有更高的同源性。将23kb片段插入pUC9质粒载体上进行可隆，并用菌落原位杂交筛选获得5个克隆，对其中两个克隆用ECoRI酶解并进行分子杂交分析，重组质粒被EcoRI切成四个片段。2.8kb片段为pUC9栽体，2kb片段为与pDC5AI质粒伸展蛋白同源性较好的片段。对于23kb片段的重组质粒有待于进一步的分析。

Successful establishment of MEKC with electrochemiluminescence detection based on one functionalized ionic liquid

Herein, one water-soluble functionalized ionic liquid, 1-butyl-3-methylimidazolium dodecyl sulfate ([BMIm(+)][C12H25SO4-]), was designed and its superiorities either used as supporting electrolytes or as additives for successful establishment of MEKC with electrochemiluminescence (ECL) detection (MEKC-ECL) method were investigated. Compared with the common supporting electrolytes such as phosphate solution, 1-butyl-3-methylimidazolium dodecyl sulfate solution used as running buffers led to greatly enhanced ECL intensities and column efficiencies for negative targets, a little increase for neutral-charge ones while maintained nearly unchanged for positive ones due to the electrostatic forces between the large cation BMIm(+) and the solutes and the hydrophobic interactions resulting from the large anion C12H25SO4.

Kinetic study of paracetamol on prolidase activity in erythrocytes by capillary electrophoresis with Ru(bpy)(3)(2+) electrochemiluminescence detection

We explored the CE with Ru(bpy)(3)(2+) electrochemiluminescence detection for the kinetic study of drug-enzyme interaction. Effects of four nonsteroidal anti - inflammatory drugs including aspirin, paracetamol, sodium salicylate and phenacetin on prolidase (PLD) activity in erythrocytes were investigated. Aspirin enhanced PLD activity whereas the other three had inhibiting effects. This may reveal their different effects on the collagen biosynthesis and catabolism that influence tumor invasiveness. Kinetic study of paracetamol on PLD showed that the value of Michaelis constant Km for PLD was 1.23 mM. The mechanism of PLD inhibition by paracetamol is noncompetitive inhibition, and the inhibitor constant K-i value obtained in our research was 9.73 x 10(3) mu g/L.