Preparation of rare earth ion induced conformation-specific anti-calmodulin monoclonal antibody

Monoclonal antibody technique was employed to detect the conformational change of calmodulin induced by metal ions. Bovine calmodulin was firstly modified by 2,4-dinitrofluorobenzene to improve its immunogenicity, then, the derived protein was saturated with trivalent europium ions and injected to Balb/c mice as antigen. After four times of immunization, a corresponding antibody was detected and its titer in serum was determined as 1 : 12 000. By fusing of the spleen cells with hybridoma cells, a europium induced conformation-specific anti-calmodulin monoclonal antibody cell strain named as 2C3 was produced successfully. The molecular recognition ability of antibody to apocalmodulin and holocalmodulin showed a significant difference, indicating that this antibody could be applied to the studies of different effects of metal ions on the conformational change of calmodulin and its interaction with target molecules.

Studies on enzymological properties of antibody elicited by meso-tetra(alpha, alpha, alpha, alpha-O-phenylacetyl benzene)porphyrin

meso-Tetra (alpha, alpha, alpha, alpha-O-phenylacetyl benzene) porphyrin was used as a complete antigen to elicit monoclonal antibody 1F2 through the immunization and cell fusion techniques. McAb 1F2 obtained was demonstrated very pure by HPLC and MALDI/TOFMS. The retention time of McAb 1F2 was 2. 63 min. The subtype of McAb 1F2 was IgG2a. The relative molecular weight was 156 678. 8. When the McAb 1F2-porphyrin was formed, the maximal absorption of the porphyrin soret region had a redshift from 408 to 416 nm and hyperchromical effect, showing that the antigen-antibody combination was rigid and intense, and the abzyme constancy was high. But compared with HRP, the activity of the abzyme was only 4. 687 5 U/mg and 1. 899 % of that of HRP. Its K-m was 20. 29 mmol/L, k(cat) 396. 82 min(-1), k(cat)/K-m. 1. 955 7 X 10(4) L . mol(-1) . min(-1).

Preparation of europium induced conformation-specific anti-calmodulin monoclonal antibody

Monoclonal antibody technique was employed to detect the conformational difference of CaM induced by metal ions. A trivalent europium ion induced conformation-specific anti-calmodulin monoclonal antibody was successfully prepared with europium-saturated calmodulin as antigen.

Fluorescence analysis of phospholipase A(2) isolated from Chinese agkistrodon blomhoffii Ussurensis venom

The general and synchronous spectra of phospholipase A(2) (PLA(2)) isolated from Chinese agkistrodon blomhoffii Ussurensis snake venom were studied. The chromophores of PLA(2) were mainly contributed by tyrosine and tryptophane residues when the intervals between the excitation wavelength and the emssion waveleagth (Delta lambda) were 20nm and 75nm, respectively. The pH of buffers could change the fluorescence intensities of PLA(2) by changing the charge distribution of its amino acid chain. Ca2+ can not only increase the emission fluorescence intensity of PLA(2) but also improve the reaction rate of PLA(2) with its corresponding substrate DPPC.

Hydrothermal synthesis and structural characterization of a mixed-valence molybdenum (IV,VI) arsenate (III): Ni(H2NCH2CH2NH2)(3)[((MoO6)-O-IV)(Mo6O18)-O-VI((As3O3)-O-III)(2)]H2O

A novel mixed-valence molybdenum(IV, VI) arsenate(III), Ni(H2NCH2CH2NH2)(3)[((MoO6)-O-IV)(Mo6O18)-O-VI((As3O3)-O-III)(2)]H2O, hydrothermally synthesized and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. The polyanion cage derives from the Anderson structure, in which the central octahedron was filled up by molybdenum(IV) and it was capped on both sides by a novel As3O63- cyclo-triarsenate(III). The title compound had a high catalytic activity for the oxidation of benzaldehyde to benzoic acid using H2O2 as oxidant in a liquid-solid biphase system. (C) 1999 Elsevier Science B.V. All rights reserved.

Magnetic and magnetotransport properties of intermetallic SmMn2Si2

The magnetic properties of naturally layered intermetallic compound SmMn2Si2 with textured structure have been studied. There exist a ferromagnetic transition at 35 K and two antiferromagnetic transitions at 120 and 230 K. The antiferromagnetic state below 230 K exhibits different magnetoresistance, with a negative magnetoresistance of 3%-4% for current I applied perpendicular to the c axis and with a positive magnetoresistance effect of about 4%-6% for current I parallel to the c axis. The observed magnetoresistance is likely to be related to magnetovolume effects. In the ferromagnetic state, a positive magnetoresistance with a maximum increase of 22% under an applied field of 5 T is observed at 4 K, and both H perpendicular to I and H parallel to I configurations show positive magnetoresistance. (C) 1997 American Institute of Physics.

Small angle X-ray scattering study of structural parameters of the aggregated state in polyamide 1010+BMI

The structural parameters of the aggregated state in the polyamide PA1010 and N,N'-bismaleimide-4,4'-diphenyl methane (BMI) system were computed by means of the desmearing intensity from SAXS and using the concept of the distance distribution function. The results revealed that the parameters Q, I(0), l(c) and L decreased with the increase BMI component, whereas O-s increased. The particle dimension Z for different BMI contents was less than 13.2 nm, and the maximum value of the distance distribution function P(Z) was found to be in the range Z = 6.5-7.0 nm.

SYNTHESIS AND CHARACTERIZATION OF POTENTIALLY BIODEGRADABLE THERMOTROPIC POLYESTERS BASED ON P-HYDROXYBENZOIC ACID AND GLYCOLIC ACID

The synthesis of novel thermotropic liquid crystalline copolyesters derived from aliphatic hydroxy acid (glycolic acid, GA) and aromatic hydroxy acid (p-hydroxybenzoic acid, PHBA) via a melt-copolycondensation process in the presence of various catalysts

MOLECULAR CHARACTERISTICS AND CRYSTALLINE-STRUCTURE OF ETHYLENE-DIMETHYLAMINOETHYL-METHACRYLATE COPOLYMERS

The relationship between molecular and crystalline structural characteristics of the ethylene -dimethylaminoethylmethacrylate copolymers (EDAM) was investigated and related to melt flow index MI and average gross content of DAM comonomer, in comparison with low density polyethylene (LDPE) produced by the common high-pressure radical polymerization process. Although the average molecular weight and its distribution are influenced predominantly by the polymerization conditions, DAM-content seems not to depend significantly on molecular weight according to the GPC-FT/IR measurement. Comonomer sequence distributions were determined quantitatively with the C-13-NMR spectra entirely assigned by DEPT and H-1-C-13 COSY techniques. The result suggests the alternating copolymerization tendency and surprisingly coincides with the simulation out-puts based on the assumption of continuous complete mixing reactor model, using Mayo-Lewis equation and the same Q-e values as previously reported on different types of copolymers such as EVA and St.DAM (VA;vinylacetate, St;styrene). It was confirmed by WAXD and SAXS analyses that the crystallinity X(c) and the thickness of lamellar crystal l(c) decreased with increasing DAM-content, whereas the a-lattice and b-lattice dimensions enlarged. X(c) and l(c) can definitely be correlated to the heats of fusion and crystallization measured by DSC. The average size of spherulites measured with light scattering photometry tends to be enlarged with decreasing molecular weight (increasing MI) and DAM-content.

分离稀土诱导位移的双稀土混合方法

稀土顺磁性诱导位移包含接触位移和偶极位移两种成份,如果把或D符号相反的两种稀土离子以适当的浓度比混合于同一溶液中。则实验上观测到的顺磁位移仅含一种成份,另外一种位移成份将被抵消。双稀土混合分离诱导位移技术要求底物分子与稀土离子间的的配位过程满足快速交换平衡条件且形成的稀土-底物配合物具有轴对称性或有效轴对称性。与其它分离诱导位移的方法相比,双稀土混合方法具有简单明确的特点。本文将这一方法应用于L-抗坏血酸~(13)C���土诱导位移的分离验证了其可行性。

稀土氨基酸配合物的电子结构与化学键性质

本文用INDO方法研究了稀土甘氨酸配合物([Er(H_2O)_4(NH_3CH_2COO)_2]_2~(6+))的电子结构和化学键性质。配合物的HOMO由甘氨酸羧基氧O_2p轨道组成,LUMO由羧基的π*(C-O)轨道组成。在配位过程中随L���Ln电荷转移,四个桥联甘氨酸和八个配位水分子分别转移2.59和1.86个电子到铒离子上,与配合物中铒离子带0.77个正电荷结果吻合。转移至5d轨道的电荷最多。配合物具有一定的共价性。对配键有主要贡献的是5d轨道。

Molecular Cloning and Expression Analysis of a Cytosolic Hsp70 gene from Laminaria japonica (Laminariaceae, Phaeophyta)

In this study, a full-length cytosolic heat shock protein 70 complementary DNA (cDNA) of Laminaria japonica (designated as LJHsp70) was obtained by reverse transcriptase-polymerase chain reaction (RT-PCR) coupled with rapid amplification of cDNA ends. The full length of LJHsp70 cDNA was 2,918 bp, with a 5' untranslated region of 248 bp, a 3' untranslated region of 696 bp, and an open reading frame of 1,974 bp encoding a polypeptide of 657 amino acids with an estimated molecular mass of 72.03 kDa and an estimated isoelectric point of 4.97. There was highly repeated sequence of CAA in 5' untranslated region of LJHsp70. The result of phylogenetic tree of Hsp70s, the BLAST program, analysis and cytosolic Hsp70-specific motif of LJHsp70 verified that the cloned LJHsp70 belonged to cytosolic Hsp70 family. Three typical Hsp70 signature motifs were detected in LJHsp70 by InterPro analysis. Under different stress conditions, messenger RNA (mRNA) expression levels of LJHsp70 were quantified by quantitative RT-PCR. To L. japonica sporophytes kept in different temperatures for 1 h, the expression level of LJHsp70 at 30A degrees C was highest and twofold higher than that at 10A degrees C. To L. japonica sporophytes kept at 25A degrees C for different times, the mRNA expression level of LJHsp70 reached a maximum level after 7 h and then dropped progressively. The expression level of LJHsp70 at 0 or 5aEuro degrees salt concentration for 2 h was twofold higher than that at 30aEuro degrees salt concentration for 2 h. The results showed that LJHsp70 may be a kind of potential biomarker used to monitor environment conditions.

扇贝、对虾基因组BAC���库构建及其重要功能基因的初步筛选和分析

基因组大片段BAC���库是进行生物遗传学和基因组学研究必不可少的基础工具。为了深入开展栉孔扇贝（Chlamys farreri）和凡纳滨对虾（Litopenaeus vannamei）基因组学研究、阐明其基因组的结构与功能、图位克隆重要功能基因、构建高密度物理图谱并最终实现与已有遗传连锁图的整合，本研究在植物基因组BAC���库构建技术的基础上，针对海洋生物的特点进行了大胆的改革与尝试，最终成功构建了C. ferrari和L. vannamei两种重要海水养殖动物的基因组BAC���库。 本文构建的栉孔扇贝基因组BAC���库，由BamHI文库和MboI文库构成。其中BamHI文库含有73,728个BAC���隆，空载率约为1%，平均插入片段约为110 kb，覆盖栉孔扇贝单倍体基因组约8倍；MboI文库共有7,680个克隆组成，平均插入片段大小约为145 kb，插入率为100%，覆盖栉孔扇贝单倍体基因组约1.1倍。两个栉孔扇贝基因组BAC���库共由81,408个克隆组成，平均插入片段约为113 kb，覆盖率约为栉孔扇贝单倍体基因组大小的9.1倍。 将栉孔扇贝基因组BAC���库的192个384微孔培养板中的73,728个BAC���隆以4 x 4点阵形式制备了高密度DNA薄膜，用于对感兴趣的基因及DNA序列的筛选。高密度DNA薄膜的覆盖率约为栉孔扇贝单倍体基因组的8.3倍。针对栉孔扇贝先天免疫系统通路的6个重要功能基因，根据栉孔扇贝cDNA序列以及异缘物种DNA序列设计了Overgo探针。利用Overgo探针对高密度DNA薄膜杂交筛选的结果显示，平均每个基因检测到7.3个潜在阳性克隆。 本研究所构建的凡纳滨对虾基因组HindIII酶切BAC���库共有102,528个BAC���隆，存放于267个384微孔培养板中，平均插入片段大小约为101 kb，空载率约为5%，覆盖L. vannamei单倍体基因组约5倍。将其中240个384微孔培养板中的92,160个BAC���隆以4 x 4的矩阵排列形式制作了5张高密度凡纳滨对虾DNA薄膜，约覆盖整个对虾单倍体基因组的4.5倍。针对6个与对虾免疫、生殖生理有关的重要功能基因设计了Overgo探针，杂交筛选出20个阳性克隆，平均每个基因有3.3个潜在阳性克隆。 以上筛选结果不仅为进一步研究这些功能基因的结构与功能、表达与调控，揭示它们在扇贝和对虾以及其他近缘种的免疫系统、抗逆和生殖生理过程中的作用机理打下了基础，同时也间接验证了栉孔扇贝和凡纳滨对虾基因组BAC���库将成为基因筛选、基因的结构与功能分析、基因图位克隆、物理图谱构建以及大规模全基因组测序等方面的有力工具。

坛紫菜中藻胆蛋白和多糖的化学结构特征研究

本文对北移坛紫菜（Porphyra haitanensis）中的藻胆蛋白和多糖进行了深入的研究，并发现其化学结构特征与南方坛紫菜存在一定差异，其主要结果如下：坛紫菜的水溶性色素粗提物经过耱酸铵沉淀和羟基磷灰石（HA）柱层析后，分离到三种藻胆蛋白，即藻蓝蛋白（RPC���、藻红蛋白（RPE）和变藻蓝蛋白（APC���。在中性介质中，其吸收光谱和荧光发射光谱与文献报告基本一致，但在酸性（PH_3）或碱性（PH_(12)）介质中，吸收光谱有明显改变，原有的荧光性质也消失。RPC���APC���分离到一种聚集体，但RPE有两种不同的聚体，用Sephadex G-100凝胶过滤方法，测得藻胆蛋白的分子量分别为：RPC 117，000，APC 122，000，小分子RPE 34，000，大分子RPE 232，000。 而且RPE的两种聚集体的吸收光谱、荧光光谱以及等电点等物理性质都有所差异。对RPE的氨基酸分析结果表明，以天冬氨酸、丙氨酸和谷氨酸为主，且酸性氨基酸的含量大于碱性基酸的含量。用分级法对南北方两种坛紫菜的热水和冷水提取多糖进行了层析分级，用~(13)C-NMR和红外光谱研究了各级分的化学结构特征，南北方坛紫菜琼胶分别主要由用1.0M和0.5M NaCl从DEAE-Sephadex A50层析柱洗脱下的带电荷的琼胶分子组成，~(13)C-NMR谱图表明坛紫菜主要由琼胶糖结构及其生物前体（硫酸基结合在L-半乳糖的第6位碳上）构成，且甲基化琼胶糖在南方坛紫菜中的含量明显比北移坛紫菜高，这是坛紫菜由南方移植北方后的明显差异，这种差异对于进一步研究坛紫菜的生理学特点是有意义的。

青藏高原毛茛科3种特有植物核型和进化研究

对青藏高原高山冰缘地区毛茛科3 种特有植物的核型进行了分析。它们的核型公式(K)、染色体相对长度组成(C. R. L. ) 和核型不对称系数(A s. K% ) 分别为: 青藏金莲花 T rollius pumilus var. tangu ticus: K (2n) = 6m + 8sm (2SA T ) + 2st, C. R. L. = 4L + 4M 2+ 4M 1+ 4S,A s. K% = 63. 57, 核型属2B型; 甘青乌头A conitum tanguticum 为K (2n) = 6m + 10sm ,C. R. L. = 4L + 8M 1+ 4S,A s. K% = 62. 54, 2B 型; 单花翠雀花Delphinium candelabrum var.monanthum 为K (2n) = 6m + 8sm + 2st, C. R. L. = 4L + 4M 2+ 4M 1+ 6S,A s. K% = 64. 34, 属3B 型。经同相关近缘种核型资料比较, 青藏金莲花核型不对称性和进化程度比金莲花T.ch inensis 低; 甘青乌头的核型不对称性和进化程度在其近缘类群(乌头组Sect. Aconitum ) 已报道的种之内最低; 单花翠雀花核型不对称性和进化水平比翠雀组(Sect. Delphinastrum ) 已报道的展毛翠雀花D. kamaoense var. glabrescens、多枝翠雀花D. maxim owiczii 和蓝翠雀花D. caeruleum 都低。这与该3 种植物在王文采先生(1979) 中国毛茛分类系统中的位置是一致的。