Abstract:The 3′untranslated region (3′-UTR) of eukaryotic mRNA plays an important role in the eukaryotic gene regulation. It controls not only the stability and degradation of eukaryotic mRNA, but the translation as well.

Abstract:The methods, principles, achievements as well as obstacles of de novo protein design were reviewed.

Abstract:The cytokine receptor superfamily and its role in mediating new pathways of signal transduction become more attractive than ever. The structural properties of cytokine receptors, the effects of Janus kinases, the activation of STAT and Ras protein and the relationship between the abnomality of signal transduction and the clinical diseases have been reviewed. This may help to correctly understand the biological effects of cytokines.

Abstract:Reverse micelles are new systems for enzymatic researches. Enzymatic properties in reverse micellar systems are different from that in aqueous buffer. The properties of reverse micellar systems and the changes of enzymatic activity and structure in reverse micelles are reviewed and the factors which affect enzymatic properties in reverse micelles are also discussed. Finally, the new progress in enzymological researches and applications of reverse micellar systems are described.

Abstract:Antifreeze proteins(AFPs),which depress the freezing point of water below the melting point (producing a characteristic thermal hysteresis),are well known for their antifreeze activity in both fish and terrestrial arthropods, but have only recently been identified in plants. The discovery, biochemical characteristics and the role in freezing tolerance of plant AFPs have been reviewed. Furthermore, the general mechanism of depressing the freezing point of water of AFPs has been discussed. The discovery of AFPs intrinsically produced by frost-tolerant plant is very significant. Isolation and characterization of genes for AFPs may provide the targeting information essential for the successful transformation of freezing-sensitive crops and fruits with genes encoding AFPs.

Abstract:Many new genes and proteins are induced under stress environment, following the increasing concentration of the abscisic acid. Up to now, hundreds of ABA-responsive genes have been cloned and most of them can be induced by exogenous ABA, these gene's expression products are deduced to play an important role in the gain of stress tolerance. As to the stress signal transduction, it is considered that there may be multiple pathways and regulation mechanisms to be involved. The recent progress is briefly summarized about the ABA-responsive genes.

Abstract:Nuclear receptor belong to a superfamily of protein.Members of this family are characterized by similar three major structure region including a highly conserved DNA binding domain.Nuclear receptor bind to specific DNA sequence and control specific gene transcription.Recent data show that,in addtion to contacting to basal transcription factors,nuclear receptor inhibit or enhance transcription by recruiting the array of coactivator or corepressor.Coactivators are necessary for the efficient transcription.CBP/P300, SRC-1and SMRT are the main coactivators and corepressor found so far.

Abstract:Growth hormone(GH) secretagogues are synthetic oligopeptides and their non-peptide mimetics which act on the pituitary and the hypothalamus to stimulate GH release. Because of their small molecular weight, high potency, oral activity and specific action, GH secretagogues can act as new agents in GH treatment. Active compounds with diverse structure, such as peptides, cyclic peptides, peptide alcohols and non-peptide mimetics have been found. Although the exact mode of action of these agents has not been fully established, they may be mimeticking a new endogenous GH-releasing factor in a new pathway for the control of the release of GH.

Abstract:Recently, attention has been focused on the association between neuronal apoptosis and neurodegenerative diseases during the deepgoing study of apoptotic cells. Many in vitro models of neuronal apoptosis have been developed, such as induced by nutrition deprivation, free radicals, glutamic acid, Ca²⁺ ,β-amyloid peptide etc. The detective technology of neuronal apoptosis is composed of testing the changes in enzymes and proteins which reflected neuronal damage, simultaneous morphological observation, and finally DNA electrophoresis etc, which could confirm the apoptosis.

Abstract:The proteasome is an essential component of the ATP-dependent proteolytic pathway in eukaryotic cells and is responsible for the degradation of most cellular proteins. The 20 S proteasome whose active site is a threonine,contains multiple peptidase activities. PA700 cappes the 20 S proteasome to form the 26 S complex, by which ubiquitinated proteins are degraded. Advances have been achieved recently in the research about the molecular organization of the 20 S and 26 S particles,their subunits,their intracellular functions and biochemical mechanisms.

Abstract:Cephalosporin acylases (CA) are enzymes that catalyze hydrolysis of the acyl side chain of cephalosporin C(CPC) or glutaryl 7-cephalosporanic acid(GL-7ACA) to yield 7-aminocephalosporanic acid(7-ACA), the most important compound in the production of many semisynthetic cephalosporin antibiotics. According to their substrates, cephalosporin acylases can be classified into two classes: CPC acylase and GL-7ACA acylase. CA was divided into five types on the basis of their homologies and mass of molecules, and the structures of their genes; some properties of these enzymes were discussed. Comparison of N-terminal nucleophile hydrolases and CA shows that CA may belong to N-terminal nucleophile hydrolases family. Thus it makes easy to understand further their physiological roles.

Abstract:Telomerase activity is associated with cancer.Telomerase inhibition is a strategy for suppression of tumor growth.The progress in inhibition of telomerase activity by peptide nucleic acids,ribozyme,differentiating agents,reverse transcriptase inhibitors and G-quartet DNA structures are reviewed.

Abstract:The PH domain is a protein module of approximately 120 amino acid residues founded in many proteins involved in signal transduction. The PH domains are similar to each other in their three-dimentional structures,and the major structure difference among them lies in the three variable loops in the structures. The PH domain is electrostatically-polarized and the variable loops are on the positively-charged surface, which may serve as a ligand-binding surface. So far ,it has been found that PH domains can interact with the βγ-subunits of G protein (Gβγ)、protein kinase C (PKC) and phosphatidylinositol-4,5-bisphosphate (PIP₂ or inositol-1,4,5-trisphosphate (IP₃)). All these implied that PH domain might play an important role in the interaction between the signaling molecules and help to form the signal transduction network.

Abstract:Exogenous genes can be introduced into specific cells for expression via receptor-mediated recognition and endocytosis of DNA-ligand complexes. The receptor-mediated gene transfer technique, its application and the perspective were described.

Abstract:Four kinds of human IL-12 expression plasmids pcDNA3/p35a, pcDNA3/p35b, pcDNA3/p40a, pcDNA3/p40b were constructed. These recombinant plasmids were co-transfected into Chinese hamster ovary cells and acquired CHO cell lines that could stably secrete IL-12. The highest expressed amount of IL-12 in CHO cell is 105 U/ml. The results showed that the expression of human IL-12 in CHO cell was affected at several levels such as recombinant plasmid structure, DNA intergration, mRNA transcription and protein transpation etc.

Abstract:Glutathione peroxidase (GPx) is one of the major cellular antioxidant enzymes in scavenging reactive oxygen species (ROS). The effects of GPx on cytotoxicity mediated by paraquat and t-butylhydroperoxide (tbOOH) in GPx overexpressing in cell lines were investigated. It was found that both paraquat and tbOOH could induce the typical features of programmed cell death (PCD) including chromatin condensation and DNA fragmentation. The GPx expressing cell clones could effciently inhibit PCD induced by tbOOH, but not by paraquat. The results suggested that GPx selectively inhibits cytotoxicity induced by ROS.

Abstract:The triplex formation between a 21nt oligodeoxyribonucleotide G₃TG₂TGT₂G₅TG₂TGT(CP1) and core promoter(Cp) fragment of hepatitis B virus(HBV) had a good specificity and stability, which was demonstrated by electrophoretic mobility shift analysis and DNaseⅠ footprinting experiment. Gel retardation assay showed CP1 could inhibit a specific cellular factor binding to Cp fragment in rat liver nuclear extracts. No inhibition of factor binding was observed by oligodeoxyribonucleotide CP3(TGTG₂TG₅T₂GTG₂TG₃), which could not form triplex with Cp fragment. These results indicate that specific repression of gene transcription of HBV DNA may be possible by triplex-formation.

Abstract:Green fluorescent protein(GFP) gene is the only new reporter gene which can express in living cells without other external substrate so far.The GFP cDNA was recombined into an adenovirus vector, then transfected into 293 cells to observe its expression. This may provide a newly monitoring method of transgenic technique.

Abstract:There are a lot of difficulties using PCR method to identify low copys of exogenous gene in transgenic animal. A method of agarose gel direct hybirdization was established. A fast and easy method to identify low copy transgenes in transgenic animal is provided.

Abstract:In vitro DNA replication system derived from eukaryotes is capable of replicating exogenous plasmid DNA containing SV40 origin of replication efficiently and accurately. Such an in vitro DNA replication system has been established. In the presence of exogenous SV40 large T antigen, shuttle-vector plasmid pZ189 could replicate efficiently in monkey kidney vero cytoplasmic extracts, which provided all the other necessary proteins for DNA replication. This in vitro DNA replication system provides a useful measure for studying the composition and function of eukaryotic DNA replication system.

Abstract:DNA purification is commonly used in molecular biology procedures. Promega's Magic/Wizard DNA purification systems make this laborious and time-consuming work easy, but most laboratories in developing countries can not afford the price of this disposable kit. A simple method to recycle the kit was successfully developed. The performance of recycled kit shows no significant difference compared with the original one. The method makes this powerful tools acceptable to most laboratories.

Abstract:Uricase-immobilized silk fibroin membrane was characterized by means of electrochemistry method. When uricase was immobilized in silk fibroin membrane, the immobilized uricase was improved largely at its stability to heat and pH, and it can be stored for long time. Based on this uricase membrane and oxygen electrode, an amperometric sensor has been developed for measurement of uric acid in flow injection analysis. The biosensor has a good reproducibility for repeatedly monitoring biosamples for 100 times respectively and is capable of detecting over 60 serum samples per hour.

Abstract:Hepatitis C virus(HCV) is a major causative agent of non-A non-B chronic hepatitis and also associated with the development of hepatocellular carcinoma. To understand the mechanism of pathogenesis and tumorigenesis of HCV and the role of the structural protein and NS3 protein in the HCV infection,three lines of transgenic mice carrying the HCV structural gene or/and NS3 gene, in which these genes are expressed under the control of the mouse metallothionein promoter, were produced simultaneously. These animals were produced by microinjecting into the pronuclei of fertilized mouse eggs with the mixture of construct carrying the structural gene and NS3 gene of HCV. The results were as follow: 1) The zygote's survival rate and birth rate were 81% and 30%, respectively; 2) After screening 60 mice that developed from the microinjected eggs by PCR, 6(10%)mice carrying the structural gene, 4(6.7%)mice carrying NS3 gene and 9(15%) carrying double genes.The total integrate rate was 31.7%; 3)The expression of transgene in the liver of Tg mice was analyzed by detection of the mRNA using RT-PCR; 4) 38 G1 mice were obtained by crossbred founder mice and normal mice, 20 mice were integrated(52.6%) with transgene; 5) No phenotypic abnormalities have been seen to date. The model may create the opportunity to examine the role of the structural and NS3 protein in HCV pathogenesis and tumorigenesis, and to assess the antiviral potential of the pharmacological agents and vaccine.

Abstract:A method for the purification of expressed maltose binding protein fused protein by using potato starch instead of cross-linked amylose have been developed. The advantage is much cheaper than amylose resin. The commercial avaiable potato starch could be directly use for purification. It provides a process for industrial purification in a larger scale.