Abstract:RRM RNA binding protein is a kind of RNA binding protein which contains one or more RNA recognition motifs and some affiliated motifs. It participates in genes' post-transcriptional regulations including splicing of pre-mRNA, cellular localization and stability maintenance of RNA. Conservative amino acids in the RRM motif are essential for RNA binding, but the specific binding depends on other factors. Some RRM RNA binding proteins are related to genetic diseases and tumors.

Abstract:Integrins are cell adhesive molecules (CAMs) comprised of α and β subunits. These CAMs usually contain a large domain, a transmembrane segment and a short cytoplasmic domain. They can interact with the extracellular matrix components, such as collagen, fibronectin, or vitronectin, to regulate the cell adhesion and trafficking. As a bidirectional transducer, integrins are involved in cell signaling by way of inside-outside signaling and outside-inside signaling. Successful implantation depends on the intimate interaction between the penetrative blastocyst and the receptive endometrium, which contains many cellular or molecular events. More recently, accumulating evidences have shown that expression of integrins during the “implantation window” stage plays an important role in “maternal-fetal dialogue” and becomes a potential marker of the receptive uterine endometrium.

Abstract:A biomimetic synthesis based on biomineralization principles leads to the development of new strategies in material science and biotectonics. Mollusk biomineralization is a process of nucleation and growth of inorganic crystals controlled by biological macromolecules, also is a process of inorganic-organic and inorganic-inorganic molecular recognition. The latest progress in studies on the characteristics of macromolecules and molecular recognition involved in mollusk biomineralization is reviewed.

Abstract:Antisense technology at least include antisense oligonucleotides technology, antisense RNA technology and ribozyme technology. Antisense technology has been widely used in the studies of G-proteins, G-protein coupled receptors and their subtypes, the specific property of G-protein in signal transduction and the “cross talk” of G-proteins involved signal transduction system with other signal transduction systems.

Abstract:There are phosphorylation sites within the C terminal domain of glutamate receptors(GluRs) which not only can be phosphorylated by protein kinases but can be dephosphorylated by protein phosphatases also. The effects of phosphorylation can enhance Ca²⁺ influx and improve the function of GluRs, whereas dephosphorylation do on the contrary. The reversible phosphorylation of GluRs keep balance in normal conditions which play an important role in synaptic plasticity such as LTP, but it can enhance excitatory neuronal damage in pathological events such as ischemic brain damage when the balance lose.

Abstract:The following studies on molecular biology of scorpion toxin genes were reviewed:(1) Strategies of cloning cDNAs or genomic genes encoding scorpion toxins;(2) scorpion toxin cDNAs and post-protein processing of precursor toxins;(3)Structural organization and pre-mRNA processing of genomic genes encoding scorpion toxins;(4)Expression of recombinant scorpion toxin genes in cells or organisms.

Abstract:V-ATPase is present in every known eukaryotic cell and plays a vital role. The study on the structure, function, assembly and the regulation of V-ATPase has achieved much progress recently. All the core subunits of V-ATPase have now been sequenced and most of their functions have been assigned to some extent. Membrane biochemistry and molecular biology studies discovered that the gene expression and the activity of V-ATPase are regulated in various ways.

Abstract:The tumor necrosis factor ( TNF ) family is a group of cytokines with multiple biological activities, including cytotoxity, anti-viral activity, immunoregulatory activities and so on. The members of the TNF family induce apoptosis by binding to their specific receptors on target cells and initiate mechanism of apoptosis in the cells. Some proteins like TRADD, FADD, RIP, TAIDD are found to participate in these signal transduction pathways. More and more novel TNF ligands, TNF receptors and caspase family members have been found.

Abstract:Glial cell-line-derived neurtrophic factor(GDNF) , neurturin(NTN) and persephin (PSP) define a new family of neurotrophic factors which are distant members of the transforming growth factor-β(TGF-β) superfamily and play widely physiological roles in vivo. Recent studies have revealed the existence of a novel family of multicomponent receptors for GDNF family, composed of distinct glycosyl-phosphatidylinositol(GPI)-linked cell surface proteins and a shared transmembrane tyrosine kinase receptor, Ret.

Abstract:The progresses on the study of neurotrophic factors such as neurotrophins and their functional receptors-tyrosine kinase receptors (Trks-TrkA, TrkB, TrkC) have been made rapidly. These factors can promote neuronal survival, outgrowth, differentiation and repairment of injury. New knowledge on the mechanism of inner ear development has been provided at both molecular and cellular levels by the application of immunohistochemistry, in situ hybridization and gene knock-out mice models in the study on the regulation of these neurotrophins and their receptors in the inner ear development. The application of exogenous neurotrophins has great clinical potential for the cure of hearing loss.

Abstract:The action of binocular cells in visual cortex is the foundation of information process of stereopsis. The disparity encode mechanism of simple cells are divided into two groups, one is position shift, the other is phase shift, but simple cells are not suited to act as disparity detector. On physiological study of some complex cells, people find some complex cells are ideally suited as disparity detector. A complex cell energy model based on these simple cells was provided. Mathematical analysis and computer simulation indicate that this model can explain many physiological data.

Abstract:The import of proteins into nucleus is targeted by nuclear localization signal (NLS) in the protein molecule. The proteins containing NLS bind the specific NLS-receptors, then cross nuclear pores and translocate into nucleus. The process of nuclear import requires the activation of cytosolic transport factors, nuclear pore complexes and the components of import machinery. When NLS is modified or masked it can not be recognized by components of the machinery, so the NLS-proteins are retained in the cytoplasm before the masks are released. Controlling the activities of transcription factors through modulating nuclear import of the proteins leads a new concept of regulation of gene expression and constitutes a regulatory level in cellular growth and differentiation.

Abstract:p185^neu/c-erbB-2 is a receptor tyrosine kinase. It's overexpressed in some adenocarcinomas, such as breast cancer and ovary cancer. It not only plays an important prognostic role, but also acts as a therapeutic target in breast cancer. Its function in signal tranduction is described. The protein engineering of antibodies against p185 and their application in cancer therapy is also discussed.

Abstract:DNA damage and repair of damaged DNA can cause cell cycle arrest. This process is consisted of three periods: recognition of damage domain in the DNA, transduction of damage signal and cell cycle arrest. Sometimes, this kind of cell cycle arrest may be failed.

Abstract:MCP is an important membrane protein for protecting host cells from damage by complement because of its wide tissue distribution and cofactor activity. A human MCP cDNA containing full encoding region was obtained by RT-PCR from Chinese human embryo. The target gene was cloned and sequenced. The data indicated that there are forty-five bases deletion compared with the counterparts previouly reported,which leads to the deletion of fifteen amino acid residues. The PCR product including 369aa open reading frame was one of the ten isoforms which had been reported before and it was named MCP-C₂.

Abstract:In order to study function of the cortical nociceptive neurons(NCNs) on the cell level with intracellular recording and stereotaxic techniques,the electrical properties of their memberane were studied.The frequency of spontaneous discharges of the neurons were diverse obviously and revealed a variety of mode in discharge. When absolute value of polarization current was lesser than 1.0 nA,the relation of I-V in NCNs was more significant(r=0.96) and the rectification insignificant;when the polarization current larger than 1.0 nA, the rectification occurred on both ends of the curve and then I-V curve showed S-type. The rectification of somatic NCNs was much significant than non-nociceptive ones(NNCNs). R_m,τ and C_m of the NCNs were evidently larger than those of NNCNs(P＜0.01 or P＜0.05).The materials obtained indicated that morphology and structural of cell membrane,volume of the soma bettween NCNs and NNCNs might have meaningful differences. It also means that physiological functions were unlike. The specificity of the electrical parameters in cell membrane might provide experimental materials for specific theory of pain sensation. Reporting to investigate electrical properties(R_m,τ and C_m) of the membrane in primary cortial nociceptive neurons had not found in literatures.

Abstract:After analyzing the secondary structures of 68 exon-intron-exon and the corresponding exon-exon sequence segments, it is found that about 90% of 5′ and 3′ terminal bases G (splicing sites) of introns are situated in the loops of secondary structures or at the ends of stems near the loops, and most of “G”s in loops are closed to the ends of loops. Approximately 92% of the connecting sites of the adjoining exons also show the similar features. About 82% of the branch point “A”s are situated in loops or at the ends of stems near the loops. Splicing sites and branch points approach each other in space because of the folding.

Abstract:［Ca²⁺］_i transients were induced in porcine polymorphonuclear leukocytes in response to ATP and ADP, while no evident change in ［Ca²⁺］_i was observed after AMP addition. The cells showed varied dose dependency upon ATP and ADP. In the Ca²⁺-free bath solution, ATP and ADP could still cause ［Ca²⁺］_i elevation in the cells. The results showed that the P2 receptors are present on porcine polymorphonuclear leukocytes and should belong to the P2Y subclass of purinoceptor family.

Abstract:The cDNAs of κ chain and Fd fragment of anti-gastric cancer mAb 3H11 were amplified by RT-PCR using degenerate primers for framework region 1(FR1) and cloned into an Fab expression vector. Expression of Fab could be detected but with no antigen binding activity. Then the Vκ and Fd genes were corrected to its genuine sequence by PCR mediated mutagenesis. The reconstructed Fab containing either corrected κ chain or Fd or both were expressed in E.coli at similar level. Correction of any one of the V region genes could partially resume the antigen binding activity. This result indicated that PCR primers introduced Vκ and Fd N terminal changes may seriously affect the antigen binding activity.

Abstract:Abnormal phosphorylation of microtubule associated protein τ is one of the major mechanism in Alzheimer neurofibrillary degeneration. It was found that casein kinase-1 (CK-1), cyclic AMP-dependent protein kinase (PKA) and glycogen synthase kinase-3 (GSK-3) differentially phosphorylate humanτ(τ3L) and thus inhibit its biological activity. Morever, the phosphorylation and inhibition of this activity of τ by GSK-3 is significantly increased if τ is prephosphorylated by PKA. Under this condition, only neglectable microtubles could be seen by electron microscopy. The data suggest that a synergistic role of PKA and GSK-3 might be involved in abnormal phosphorlation and functional inhibition of τ in Alzheimer disease.

Abstract:The comparison of Watergate technique and other solvent suppression methods showed that Watergate technique is easy to realize and can give low t₁ noise spectrum. With Watergate-NOESY and Watergate-TOCSY, the assignment of most labile protons of G,C in dsDNA fragment d(5′-TTTCGCGC)·d(3′-AAAGCGCG), which can be recognized by the transcription factor E2F, was made.

Abstract:Distribution of gycine-immunopositive neurons in the visual center of the hamster was studied by immunocytochemical technique, quantitative analysis was made statistically. The results showed that except the layerⅠ,the glycine-immunopositive neurons are distributed through all layers of the visual cortex. The mean density is 1 046/mm². An average of 23.9% of the neurons in visual cortex is immunopositive for glycine. The densities of positive glycine neurons in the superficial stratum and deep stratum of superior collicular are 750/mm² and 781/mm² respectivelly and their percentage are 19.5% in superficial layer and 20.3% in deep layer. Glycine-immunopositive neurons of visual center include different type of cells.

Abstract:Recombinant glutathione S-transferase (GST) Vpr fusion protein was used as target to select Vpr binding peptide from phage peptide library. By immobilized the GST or GST fusion protein to glutathione agarose gel, binding phage could be quickly panned and eluted by reduced glutathione. The sequencing result show that a WWXF motif exist among the Vpr binding peptide. Comparing with the classic biopanning method by coating target protein on plate this provide more quick and convenient way to screen binding protein from phage peptide library.

Abstract:Quantitative study of protein requires accurate determination of protein concentration. Yet without a reliable value of protein extinction coefficient, it is difficult or impossible to determine protein concentration by the usual UV spectroscopic means. On the basis of the extinction coefficients of tyrosine and tryptophan in 0.1 mol/L NaOH solution, a method was introduced for determining accurate extinction coefficients for proteins at 280 nm by protein alkaline hydrolysis. Meanwhile, this method is calibrated against several proteins whose extinction coefficients are known from references. The results show that the extinction coefficients of these proteins determined by the alkaline hydrolysis method are accurate.

Abstract:To establish a highly sensitive time-resolved immunofluorometric assay of human interferon-gamma. A two-site “Sandwich”-type time-resolved immunoflourometric assay for human interferon-gamma is described. It is based on usage of specific polyclonal and monoclonal antibodies. The polyclonal antibody to bind the interferon-gamma in samples are immoblailized on the surface of microtiter plate strip wells.Following capture of IFN-γ present in sample. Then monoclonal antibody, which is biotinylated,is added to wells.The second biotin labeled antibody will allow the subsequent specific binding of Eu³⁺ labeled streptavidin. After the immunoreactions completed, the bound fraction of Eu³⁺-label is quantified by dissociating it in a fluorescence-enhancement solution and measuring its fluorescence with Wallac 1234 fluorometer. The sensitivity of the assay is 0.02 μg/L. The standard curve is linear from 0.02 μg/L to 400 μg/L. The time-resolved immunofluorometric IFN-γ assay is quick, sensitive and suitable for testing large numbers of samples, and may be useful in both industrial producing and clinical studies.

Abstract:Alkaline phosphatase(AP)-labelled streptavidin (SA) is the most important general reagent in enzyme-amplified time-resolved fluo-roimmunoassay. A two step method of AP-labelled SA using glutaraldehyde was described. Characteristics of the labelled product AP-SA were measured using the self prepared fluorescence developing solution and the substrate-5-fluorosalicyl phosphate. The labelled recovery of AP is 38.7%.The relationship between diluting times of the AP-SA and signal/noise ratio of Tb³⁺ is linear when diluting the AP-SA 200～12 800-fold. Enzyme activity of the AP-SA is stable during two months at least.

Abstract:The purpose of the experiment is to use pro-urokinase as a model to find a way of recovering proteins from SDS-PAGE gel for MALDI-TOF MS. The recovering method includes steps of electroelution, desalting and SDS removal. Discontinuous conductivity gradient method for electroelution, centrifugation ultrofiltration for desalting and cold acetone method was used for SDS removal. The result shows that the method is feasible at least for some proteins (e.g.pro-urokinase and bovine serum albumin).

Abstract:The Immuno-PCR antigen detection system has been developed for several years as a modefication of the ELISA method. But only a few of laboratorise applied this high sensitive quantitative assay, since it needs special apparutus or complicated operations.A new procedure of Immuno-PCR was established, which coats antibody or antigien on PCR tubes with 0.8% glutaraldehyde instead of on the wells of titer plates with alkine carbonate buffer. The assay could be coducted with simple handlings and ordinary apparutus, and a high sensitivity is obtained up to 10⁵ times higher than that of ELISA in S-100 antigen detection.

Abstract:Total RNA was prepared from fat body of the silkworm, Bombyx mori, 9 hours after injected by E.coli K12D31. Single-strand cDNA was synthesized by reverse transcription (RT). Partial fragments of cecropin A cDNA were obtained, cloned and sequenced, by PCR technique with a pair of degenerate primers designed according to the amino acid sequence of CM4 in Bombyx mori and cecropin A in Hyalophora. These laid a foundation for further research on preparation of the probes of cecropin A for screening the silkworm cDNA library.

Abstract:Trypsin remains active after autoclaving at 120℃ in acidic solution. This method of sterilization has been used routinely in cell culture work and found more simple, reliable and economical.

Abstract:CL analysis technology were rapidly developed in recent years. It is widely used in the fields of free radicle analysis, chemiluminescence, ultra-weak CL in live system, CL immunoassay, bioluminescence. Principle of ultra-weak chemiluminescence analysis is introduced. Research and practice that was processed by chemiluminescence analysis were explained with several investigation results.

Abstract:The SIP technology is achieved by exploring the modular structure of minor coat protein Ⅲ of filamentous phage, and based on the technique of phage display. In SIP, the infectivity of an otherwise non-infective phage particle is restored strictly upon the binding occurrence between interacting molecular partners. Some mechanistic dissection studies showed that SIP is a novel extremely effective and highly specific technique for identifying interacting molecular pairs, and it is very promising.