Generation and use of synthetic peptide combinatorial libraries for basic research and drug discovery.

Existing methods for the synthesis and screening of large numbers of peptides are limited by their inability to generate and screen the requisite number (millions) of individual peptides and/or their inability to generate unmodified free peptides in quantities able to interact in solution. We have circumvented these limitations by developing synthetic peptide combinatorial libraries composed of mixtures of free peptides in quantities which can be used directly in virtually all existing assay systems. The screening of these heterogeneous libraries, along with an iterative selection and synthesis process, permits the systematic identification of optimal peptide ligands. Starting with a library composed of more than 34 million hexa-peptides, we present here the precise identification of an antigenic determinant recognized by a monoclonal antibody as well as the straightforward development of new potent antimicrobial peptides.     

Construction of human combinatorial antibody library and screening of monoclonal antibody Fabs to human immunodeficiency virus type I

The heavy chain Fd genes and K chain genes of immunoglobulin were amplified by RT-PCR from PBL of three volunteer donors with HIV-positive. Phage antibody library was constructed with the Fd genes and K chain genes using pComb3 as vector. Three-round selection against coated gp120 showed specific enrichment of phage antibodies. After the third round selection, 40 out of 50 clones exhibited gp120 binding capacity. The specificity of the clones was verified by ELISA and competition inhibition ELISA. The VH was derived from subgroups VH Ⅱ and VHⅢ, VL belonged to subgroups VKⅠ and VK Ⅲ with DNA sequencing. These results suggest that the antibodies obtained are specific to gp120.     

Construction and use of human chromosome jumping libraries from NotI-digested DNA

A basic difficulty in the molecular analysis of genes identified by mutations in the mammalian genome is the need to cover genetic distances corresponding to several hundred kilobases or more by molecular techniques like chromosome walking. In chromosome jumping, this limitation is overcome by the deletion of all but the extreme ends of large DNA molecules before cloning. We describe here the construction and characterization of a NotI 'jumping library' from human DNA. To characterize this library, random clones were analysed by restriction mapping. Clones carrying unique end fragments were characterized further by hybridization to Southern blots of NotI-cleaved human DNA separated on pulsed field gradient (PFG) gels. As a first step in a directional walk, the library was screened with a clone containing a NotI site cleaved in genomic DNA ('NotI linking clone') localized to the distal third of the short arm of human chromosome 4 (A.-M.F. & T.P., unpublished data). Starting and end points of two identified clones were positioned within a restriction map covering 850 kilobases.     

高校图书馆与企业联合读者培训模式的探讨

由于高校图书馆馆藏结构、服务模式等方面的变化,使得读者在充分利用现代化图书馆方面有了新的困难,本文提出由数据库提供企业与高校图书馆联合开展高校的读者信息素质教育工作的模式,无论是对图书馆的利用、读者信息素质教育、企业的发展等均有深远的意义。     

Inhibition of P. falciparum growth in human erythrocytes by monoclonal antibodies

Malaria is increasing in incidence and prevalence in most tropical areas and is a major problem for both individuals and communities. Current malaria research is aimed at developing vaccines and, for this, it may be useful to define Plasmodium antigen(s) related to the development of a protective immune response in the host. Monoclonal antibodies have recently been shown to interfere with rodent malaria infection (Plasmodium berghei) at the sporozoite or merozoite stage. We have now raised monoclonal antibodies against single antigenic determinant(s) of Plasmodium falciparum and report that some of them inhibit the growth of erythrocytic forms of P. falciparum in vitro.     

Isolation and partial sequence of recombinant plasmids containing human alpha-, beta- and gamma-globin cDNA fragments.

Human globin cDNA-derived recombinants with plasmid pCR1 have been prepared for use as specific hybridisation probes and for the partial sequencing of alpha-, beta- and gamma-globin genes.     

Chemical rescue of cleft palate and midline defects in conditional GSK-3beta mice

Glycogen synthase kinase-3beta (GSK-3beta) has integral roles in a variety of biological processes, including development, diabetes, and the progression of Alzheimer's disease. As such, a thorough understanding of GSK-3beta function will have a broad impact on human biology and therapeutics. Because GSK-3beta interacts with many different pathways, its specific developmental roles remain unclear. We have discovered a genetic requirement for GSK-3beta in midline development. Homozygous null mice display cleft palate, incomplete fusion of the ribs at the midline and bifid sternum as well as delayed sternal ossification. Using a chemically regulated allele of GSK-3beta (ref. 6), we have defined requirements for GSK-3beta activity during discrete temporal windows in palatogenesis and skeletogenesis. The rapamycin-dependent allele of GSK-3beta produces GSK-3beta fused to a tag, FRB* (FKBP/rapamycin binding), resulting in a rapidly destabilized chimaeric protein. In the absence of drug, GSK-3beta(FRB)*(/FRB)* mutants appear phenotypically identical to GSK-3beta-/- mutants. In the presence of drug, GSK-3betaFRB* is rapidly stabilized, restoring protein levels and activity. Using this system, mutant phenotypes were rescued by restoring endogenous GSK-3beta activity during two distinct periods in gestation. This technology provides a powerful tool for defining windows of protein function during development.     

Construction of human and mouse brain cDNA libraries and isolation of full-length cDNAs

cDNA libraries from aborted human 3-month fetal brain,adult rat and mouse brain were constructed by using a yZAP express cDNA library construction kin.Low molecular weight fragments of the second strand cDNASA were removed by flowing through the Sepharose CL-4B column and the frractionated long,Middle,Short fragments and the combined fragments weire respectively inserted into clone vectors to construct the cDNA libraries of the brain of human 3-month fetus.The 5'ends of 1200 clones from each of human fetal brain cDNA libraries were sequenced.A total of 894 ESTs were obtained and some full-length clones were squenced.By andalyaing the se-quences,12 novel full-length cDNAs were obtained.     

新组合概型的生成及其性质

以“秩”的形式给出了偏序集拟阵中限制与收缩两种运算作用相等的一个充要条件,显示了秩函数在研究偏序集拟阵中的重要作用.详细地讨论了产生新组合概型的限制、收缩、截短和延伸等运算,并研究了它们的一些性质.     

人GrnE单克隆抗体的制备和鉴定

为了制备获得针对人Grn E单克隆抗体,将原核表达GST-Grn E蛋白作为免疫原,免疫Balb/c小鼠,经过融合及初步筛选,获得5株针对Grn E的单克隆细胞株.选取其中3株(1D5、2E1和3F7)制备腹水,并通过western blot和免疫荧光染色对该3株单克隆抗体进行鉴定.在此基础上,进一步对1D5和3F7两株单克隆抗体是否可以用于免疫沉淀实验进行了检测.上述实验表明,本研究成功制备了针对Grn E结构域的单克隆抗体,而且所制备的单克隆抗体具有良好的特异性.     

抗人FXYD3单克隆抗体的制备与初步鉴定

【摘要】目的 制备抗人FXYD3单克隆抗体（McAb）并鉴定其生物学特性。方法 以固相合成法获得的FXYD3合成多肽与载体蛋白KLH偶联后免疫BALB/c小鼠,采用杂交瘤技术制备抗人FXYD3 McAb。用ELISA 、Western Blot、免疫组化技术对抗人FXYD3 McAb的亚型、效价、亲和力及特异性进行鉴定。结果 筛选出两段较好的优势抗原表位,分别为NDLEDKNSPFY和KFGQKSGHHPGETPPLITPGSA获得四株可稳定分泌抗人FXYD3 McAb的杂交瘤细胞株02A12C4、02F1E8、02E6B10与03A10E11,亚型鉴定重链均为IgG1,轻链为kappa链。间接ELISA法测定效价均在为1∶104以上。其中02F1E8效价为1∶105以上,亲和常数为3.11?08 L / mol。免疫组化分析显示了FXYD3均匀分布于肝癌细胞与人胰腺癌Bxpc-3细胞系细胞的胞膜上。结论 成功制备了四株抗人FXYD3 McAb,其中02F1E8纯度好、效价高及特异性强。为进一步研究FXYD3在肿瘤组织及细胞系中的表达及临床意义奠定了基础。     

Unique allelic restriction fragments of the human Ha-ras locus in leukocyte and tumour DNAs of cancer patients

White blood cell DNA from cancer patients and DNA from tumours and tumour-derived cell lines frequently demonstrated allelic restriction fragments of the Harvey ras oncogene locus not found in the unaffected population. The presence of such unusual alleles may be linked to susceptibility to cancer.