Abstract:The neu gene is known to encode a PTK-activity-bearing phosphoprotein which is one of the homologous proteins of epidermal growth factor receptor (EGFR). Amplification and (or) overexpression of neu gene have been found in various human cancers recently. Some protein factors and chemical agents can suppress neu gene transcription or reduce the PTK activity of p185^neu, resulting in the inhibition of metastasis and proliferation of cancer cells with neu overexpression.

Abstract:Hypoxia-inducible factor 1(HIF₁) is a nuclear factor whose production and DNA binding activity is induced by hypoxia in a variety of cell types, which is composed of two different subunits: 120 ku HIF_1α and 91～94 ku HIF_1β. HIF₁, as a hypoxia inducible transcription factor, promotes the expression of erythropoietin gene and glycolytic enzymes gene etc. in response to hypoxia which maintain the oxygen homeostasis.

Abstract:The insulin-like growth factor binding proteins(IGFBPs)are a family of soluble proteins that bind the insulin-like growth factors(IGFs) with high affinity.These proteins not merely carry the IGFs and prolong the half-life of IGFs,but have influences on both the bioactivity and distribution of IGFs in the extracellular environment.Under the different experiment conditions, IGFBPs can either inhibit or augment IGFs actions. In addition, IGFBPs appear to have intrinsic biological activity independent on IGFs. Research on molecular structure,gene expression, post-translational modifications, and bioactivity of IGFBPs were summarized.

Abstract:The members of the molecular chaperone families are widely distributed from prokaryotes to eukaryotic cells. The molecular chaperones function in vivo to recognize and stabilize unfolded or partially folded polypeptides, and protect polypeptides from inappropriate intra- or interchain interaction. In some circumstances, the chaperones interact with native proteins and promote rearrangement of oligomeric complexes. Stemming from their ability to recognize and modulate the state of folding of polypeptides within cells, the molecular chaperones serve many functions including mediating mitochondrial protein translocation, regulating signal pathway and being involved in microtubule nucleation.

Abstract:Many checkpoint genes and proteins have been screened from different species and cells until now, such as ATM, RAD53, CHK1 etc. There are a lot of reports about their function in checkpoint control pathways as well as the correspondances with cancers.

Abstract:Oligosaccharides, especially the glycans on the glycoconjugates, play important roles in the cell recognition, signal transduction and receptor modulation phenomena in the life processes. The application of new techniques such as HPLC, capillary electrophoresis, MS, NMR, fluorophore-assisted carbohydrate electrophoresis and reagent array analysis method, allows the isolation and structural determination of oligosaccharide more rapid, convenient and accurate. Also it is now possible to understand more complete the structure-function relationship of the trace oligosaccharide, while a variety of powerful tools are combined.

Abstract:A number of stress-induced proteins are produced in plants in response to drought stress, among which dehydrin is the most common one. Concerns on the highly conserved sequence and the large quantity expression of dehydrin have led to numerous significant findings about the biological role and the regulation of gene expression of the stress-responsive proteins. Recent progress of the dehydrin research is described.

Abstract:The activity of fibroblast growth factors(FGFs)is mediated by a dual-receptor system. This comprises a family of four receptor tyrosine kinases(FGFRs)and heparin sulphate proteoglycans(HSPG). The binding of the FGFs to the FGFRSs is marked by a pattern of overlapping specificity despite alternative splicing events generating a large number of FGFRs.HSPG receptors may stimulate the combination between the FGFs and FGFRs, and provide additional specifity allowing a cell to fine tune its response to the FGFs.FGFRs induce the activities of donwstream signal molecules which then act in different ways that affect the cell's development, mitogenesis, and neuronal differentation, respectivly.

Abstract:Recent achievements in researching botulinum neurotoxin actions′ mechanism are as follows. (1) Electrophysiology experiments demonstrate the decrease of Ca²⁺ sensitivity in the transmitter release system is responsible to the synaptic block induced by BoNTs. Directly intracellular introducing of BoNTs shows BoNTs have no intracellularly cholinergic specificity and inhibit secretion from all types of cells. (2) Binding experiments indicate the binding of BoNTs includes an initial low-affinity step and a subsequent high-affinity step. The low-affinity receptors might be gangliosides, while the high-affinity receptor might be synaptotagmin, a synaptic vesicle membrane protein. (3) The intoxication of BoNTs is more appropriately described by a four-step process: binding to the preferential receptors, internalizing by the process of receptor-mediated endocytosis, membrane translocation and escaping endosomes by an acidification process, as well as selectively cleaving the proteins involved in exocytosis as an enzyme. The carboxyterminus and the aminoterminus of the heavy chain as well as the light chain play important roles in tissue targeting, internalization, and intracellular target modification respectively. The internalized light chain cleaves the proteins involved in the fusion of synaptic vesicles so that the exocytosis as well as the transmitter releases are inhibited.

Abstract:The biological activities of fullerenes and their derivatives have been recognized since early this decade.The prelimilary research indecates that they have the unique performences in anti-HIV activity, enzyme inhibition, DNA cleavage etc., and they will be widely applied in biochemistry, medicine, pharmaceutics.

Abstract:Expressing of antibodies in plants is one of the fields of plant gene engineering, which was developed recently. It refers to introducing into plants and expressing in them the genes encoding antibodies or antibody fragments. The most intriguing potential of expressing of antibodies in plants is inexpensive large-scale production of antibodies for therapeutic and clinical use. In addition, altering traits is possible by manipulating plant metabolism using plantibodies. This approach could aslo be applied to conferring pathogen and insect resistance to plants. At present, there are still some questions about plantibodies commercialization.

Abstract:The methylotrophic yeast, Pichia pastoris heterologous gene expression system was utilized to produce attractive levels of a variety of intracellular and extracellular proteins of interest. Lateolabrox japonicus growth hormone gene was cloned into the yeast integrative vector pHIL-D2, which was then transformed into his4 mutant yeast GS115. PCR fast detection methods was performed to screen the positive transformants and dot-blotting was used to screen the multiple-copy transformants. Via inducing AOX1 promoter by methanol, growth hormone could be expressed intracellularly. SDS-PAGE and Western blot were applied to confirm the product.

Abstract:Multidrug resistance (MDR) of tumor cells lead by overexpression of MDR1 gene is considered as a major obstacle to successful chemotherapy. The amount of MDR1 mRNA has been correlated with the degree of drug resistance, so precise quantification of MDR1 mRNA should be useful in improving monitoring and design of chemotherapy. A competitive reverse transcription-polymerase chain reaction (RT-PCR) assay for the absolute quantification of MDR1 mRNA is described. In the first, a plasmid was constructed, which contain a MDR1 cDNA fragment. The cDNA fragment share the same MDR1 primer sequence as the cellular cDNA, but it was less 58 bp in length than cellular cDNA because of shortening by EcoRⅤ. In the second, the cDNA was transcripted in vitro as an internal standard, and then it was done RT-PCR procedure together with cellular cDNA. The two kinds of amplified cDNA fragments could be distinguished after agarose gel electrophoresis, because there were difference in their length. The concentration of cellular MDR1 mRNA was derided from the ratio between the intensities of the bands corresponding to the amplified products. The test for characterizing the MDR1 expression offers high sensitivity and specificity and is therefore of great clinical relevance.

Abstract:The effect of whole-body irradiation (WBI) on transcriptional regulation in mouse spleen was studied using gel electrophoresis mobility shift assay (EMSA) and oligonucleotide competitive inhibition analysis. Binding of nuclear protein extract from splenic cells to ［γ- ³²P］ ATP labeled CREB and NF-κB consensus sequences was found to be increased 4 h after WBI with 75 mGy X-rays, being 7 and 5 times higher, respectively, than that of the sham-irradiated control. Competitive inhibition analysis with excessive amount of unlabeled consensus sequences completely blocked the binding in corresponding EMSA, demonstrating the specificity of the reaction. The results suggest that low dose WBI could selectively activate the transcription factors CREB and NF-κB, which would induce specific gene transcription in the splenic cells leading to their functional activation.

Abstract:CPP32 has been recently reported to be involved in the early process of programmed cell death. To further study CPP32 and its regulation in the cell, a 830 bp cDNA was cloned by RT-PCR from CNE cells encoding the full length human CPP32 protein and high level expression was achieved in E.coli by using GST expression system. The results showed that the bacterially expressed CPP32 protein is auto-cleaved and capable of cleaving in vitro-translated PARP, thus is fully functional.

Abstract:Porous cellulose acetate beads are formed for enzyme immobilization. The carrier is activated by being oxidized with NaIO₄, after which amyloglucosidase is attached to it. The optimal reaction conditions and the kinetics of the immobilized amyloglucosidase are determined and compared with those of the free enzyme. The activity of the immobilized amyloglucosidase shows no decay after 10 batches of starch hydrolyses, the total reaction time of which is more than 24 h at 55℃.

Abstract:Total RNA was prepared from pituitary of bovine.mRNA was isolated from the total RNA. cDNA was synthesized as template used in PCR for amplification of cDNA for α subunit of bovine follicle stimulating hormone. Sequence analysis showed that the obtained cDNA fragment is 380 bp and all these nucleotides except one coding for Lys of No.24 are as same as that Erwin reported. Comparison of bovine, human and rodent indicated that the amino acid and nucleotide sequences of the α subunit in these mammalian species are highly conservative.

Abstract:Biosensor highly sensitive to hydrogen peroxide has constructed by immobilizing horseradish peroxidase in Eastman-AQ-N-methyl phenazine methosulphate modified electrode via cross-linking. Cyclic voltammetry and chronamperometry were employed to demonstrate the effective electron transfer between immobilized horseradish peroxidase and a glassy carbon electrode via N-methyl phenazine methosulphate in Eastman-AQ polymer film. Because of high efficiency of bioelectrocatalytic reduction of hydrogen peroxide via N-methyl phenazine methosulphate, the hydrogen peroxide sensor was combined with glucose oxidase and β-galactosidase for bienzyme and trienzyme-based biosensor for determination of low glucose and lactose. The biosensors for hydrogen peroxide, glucose and lactose possessed a wide variety of advantages including long stability, rapid response times, wide dynamic range, high sensitivity and selectivity. Comparison of glucose biosensor with colorimetric method with glucose oxidase and peroxidase for the determination of serum glucose from diabetic patients indicates that the results display a good consistency.

Abstract:A method for photopolymerization of polyacrylamide gel with methlene blue (initiator), sodium toluenesulfinate (reducer) and diphenyl-iodonium chloride (oxidizer) features simple operation, reliable gelation, good reproducibility and easy control of gelation, which is advocated as a valid alteranative to the most popularly used AP/TEMED and Rf/TEMED ones. This method was tested for SDS and uDGGE with acidic buffer system, and satisfactory results were obtained. These preliminary experiments demonstrate that this novel method of photopolymerization gives reliable results and is another choice for gel polymerization.

Abstract:The epitopes of plasminogen (Pg) of serum lipoprotein(a)［Lp(a)］［Lp(a)-Pg］ were determinated by ELISA using monoclonal anti-apo(a) as the capture antibody and quantitating with anti-Pg enzyme conjugate. The assay range by this method was from 28 to 880 mg/L. The mean intra- and inter-assay coefficients of variation were 4%～6% and 7%～9%, respectively. The serum Lp(a) concentration was positively correlated with serum Lp(a)-Pg level and negatively with Lp(a)-Pg level to total Lp(a) ［Lp(a)-Pg/Lp(a)］ ratio. Serum Lp(a) concentration, Lp(a)-Pg level and Lp(a)-Pg/Lp(a) ratio were found significantly elevated in CHD and CRF patients compared with those in the controls. Determination of Lp(a)-Pg level and Lp(a)-Pg/Lp(a) ratio in patients with high incidence of atherosclerosis have special value.

Abstract:Manipulation of macromolecules is becoming an interesting research subject both in physics and biology recently. Linear phage virus has been aligned in one direction on atomic flat surfaces by a special method named “molecular combing”. Atomic force microscopy was used to check the results. The related mechanism has been discussed.

Abstract:A novel hybrid cecropin AD gene was synthesized. The synthetic cecropin AD gene is 140 by in length. It was cloned into the pCR^TM2.1 vector. It was confirmed that the DNA sequence of the synthetic cecropin AD gene was identical with that of the designed gene by DNA sequencing.

Abstract:To prove up production and effect of free radicals on virus-induced pathogenesis, the influenza A/FM1/1/47 (H₁N₁) was adapted to mice by nostril inoculation. The results demonstrated that the oxygen free radical levels and xanthine oxidase activity in the lung tissues from the mice after infection by virus raised remarkably. These were positively correlated with lung tissues injury and mice mortality. The results demostrated that oxygen free radicals may involve in influenza-induced pathogenesis in mice, and may be an important factor causing tissue injury.

Abstract:With the chromosomal DNA of human blood lymphocytes as template, neurotrophin-4 coding genes were amplified by PCR and recombinated into phage vector M13, which were sequenced by using Sanger's single-stranded DNA terminal termination method. The sequence of the cloned gene is completely the same as that reported in the literature.

Abstract:A purification method for phage DNA is introduced. Phage particles are precipitated by polyethylene glycol (PEG), then purified by DEAE-cellulose DE52 and extracted by phenol. This modified method is more convenient, rapid and economical than the traditional method of phage DNA purification and can obtain phage DNA with high purity.