Abstract:Immunoglobulin (Ig) gene expression is a B-cell-specific and developmental-stage-specific event. Several factors are involved in Ig gene transcription,including Oct 2,NF-kB and helix-loop-helix (HLH) proteins.The regulation of Ig gene transcription by these three kinds of protein factors are focured.

Abstract:The effects of zinc on genetic regulation are extensive and conspicuous.It was shown that zinc participates in genetic regulation mainly through infecting the regulation of gene expression.the structure and function of chromatin, the conformation of DNA and the biosynthesis of nucleic acid.The mechanisms of zinc acting in these processes were discussed as well.

Abstract:Several cases of protein splicing have been found recently which is different from so called RNA splicing.The peptides which are excluded from premature proteins are called″protein intronn″.Some of the protein introns have endonuclease activity and the DNA fragments coding for protein introns have defined a new kind of mobile genetic element.The discovery, mechanism and evolution of protein introns are focused.

Abstract:Programmed cell death(PCD),unlike the other form of cell death(necrosis),is an active process of cellular suicide.It plays an important role in embryogenesis,tumorigenesis and clonal selection in the immune system. bc1-2，a potential physiological regulator of PCD,can not block all kinds of programmed cell death mediated by various stimuli.bc1-X,a recently found gene which encodes two different proteins,takes an important part in both positive and negative regulation of PCD. bc1-2 is regarded as a member of the third category oncogenes because its blocking of PCD results in tumorigenesis.

Abstract:The expression of human granulocyte-macrophage colony stimulating factor (hGM-CSF) gene is finely regulated at the levels of both transcription and post-transcription. The transcriptional regulation involves some cis-active elements,such as the CATT(A/T) repeat sequence, GC-rioh sequence，CK-1, CK-2，kB specific sequence and inducible CsA-sensitive enhancer, which are all located in the 5'-untranscriptional region of the hGM-CSF gene.At the post-tanscriptional level,a 62bp AU-rich sequence located at 3'-untranslation region of the mRNA is related to the stability of hGM-CSF mRNA. These mechanisms can up or down regulate the production of hGM-CSF when the cells receive the singnals from the stimuli of cytokines and other stimulating factors.

Abstract:The application of ultrasound to biotechnology is one of the new interesting research fields. A number of studies has shown that some biochemical processes can be activated by ultrasound in the presence of enzymes and cells. Generally,lower intensity ultrasound can increase the activity of enzymes and immobilised enzymes or improve the metabolism of cells by the improvement of mechanism of mass-transfer of substrates.The advance and future of applications of ultrasound to biotechnology is discussed by some examples given.

Abstract:Glycophorin(GP or sialoglycophorin)-A,B.C and D constitute a group of red blood cell (RBC) transmembrane proteins.GPA carried the M-and N-blood group antigens. GPB represents the Ss,and U antigens.GPC and GPD exhibit the Gerbich receptors. Some homologious peptide sequences exist in four of the GPs,but extensive similarities are within GPA and GPB family,GPC and GPD family as well.Because of its abundant sialic acid content，GPA plays a critical role in preventing and minimizing interactions of RBC to RBC, and of RBC to other cells in circulation. Binding of a ligand specific for GPA induces profound changes in membrane material behavior. GPC has a important role in regulating RBC shape,membrane deformability and membrane machinical stability. The functions of GPA and GPC are associated with band 3 and 4.1 proteins respectively.

Abstract:Framework model emphasizes that secondary structure formation is the foundation of protein folding initiation.The paper presents the solution conformation of protein fragment and methods of conformation elucidation，and De novo design of peptide with secondary structure.Also,the application of these achievements in constructing the theorftical model of folding initiation and progress on research of protein folding initiation up to date are detailedly reviewed.

Abstract:Peptide library is a collections of peptides.The peptides display onthe N-terminal of p Ⅲ or p Ⅷ coat protein of bacteriophage through gene cloning.This might be used in the fields associated with molecular recognition,such as: drug design, selection of enzymes inhibitor, vaccines selection, interaction of proteins,etc.Peptide library technique is a lately developed technique with high practical and theoretical value.Peptide library birth,development and potential applications in the future are reviewed.

Abstract:Interleukin-2(IL-2)is an important immune regulator.Recently it is found that IL-2 is also an analgesic molecule.Using the potassium iontophoresis as pain stimulus to induce tailflick and taking the intensity of current (mA) at the moment of the response as the pain threshold (PT),it is reported that mutant 20 Leu-IL-2 (20Asp→Leu),which could not bind to the βsubunit of IL-2 receptor and thus had no immune activity, could increase the PT of the rats, indicating that the analgesic and the immunal functions be related to two different domains in IL-2 molecule. Mutant 45Val-IL-2 (45Tyr→Val)，which had immunal activity, had no analgesic effet, suggesting that the 45Tyr be crucial for the analgesic effect of IL-2 and the analgesic domain be located around the 45Tyr.

Abstract:A preliminary study was made on the characterization and distribution in human tissues of AF9-recognized antigen. The results demonstrated that the antigen is a complex protein composed of carbohydrate,lipid and protein and susceptible to heating to 100℃.The determinant of AF9-recognized antigen was not present in the ferritin and carcinoembryonic antigen. Western blotting revealed that AF9-recognized antigen with molecular weights of 51,56,67 and 73 kD.Immunohistochemical staining showed that the antigen mainly existed in the cytoplasm and on the membrane of breast cancer cell, and also could be observed in some other tumors, but no staining was detected in normal tissues. The AF9-recognized antigen may be a new tumor-associated antigen.

Abstract:PF gel-type resin has been synthesised by poly-condensation of hydroquinone with formaldehyde in the presence of acidic solution.The gel-type resin is cheap and easy to preduce,non-toxic,porous,hydrophilic, extremely stable.It is a effective carrier for the simple and rapid immobilization of various enzymes and proteins.The amounts of bound protein (BSA) and glycoamylase in one gramme of the dry carrier were 558mg and 330mg respectively,the activity recovery of 84% for immobilized glycoamylase was obtained. The coversion(%)for starch into glycoase, using immobilized glycoamylase is as high as 93%.A new kind of modified PF gel-type resins were synthesised by copolymerization of hydroquinone and some resorcin with formaldehyde. Thus PF and modified PF gel-type resins are superior carriers for immobilization of enzyme.

Abstract:A method is described for incorporation of water-soluble SpA into phospholipid monolayer using covalent SPA-stearate conjugates, and then transferring the monolayer on a pre-treated silica surface to form a SpA containing membrane.Stearic acid containing a reactive N-hydroxysuccinimide ester group is synthesized,and the derivative is reacted with SpA in a deoxycholate buffer. The modified SpA (m-SpA) has the solubility properties very similar to intergral membrane proteins. The CD results show that the content of β structure in the m-SpA is incresed in lower lipid coupling degree, but in higher modification the random coli content rapidly increased. After SpA is incorporated in the DPPA monolayer, unmodified SpA is readily ejected from the monolayer but m-SpA incorporates into the monolayer stably. The incorporation of the protein is proportional to the lipid coupling degree. The IgG binding ability of m-SpA decreases with the increase of the lipid coupling degree. The ability is further reduced about 20%一30% when m-SpA is incorporated in the membrane, which might be due to the incorporating procedure.

Abstract:Tb(Ⅲ) as a fluorescent probe was used to study the surroundings of metal ions in FP (fibrinolytic principle).There is a high affinity site of Ca^2＋ in every FP molecule and Ca^2＋ ions are located near the Trp.When Tb (Ⅲ)-FP was excited by 222nm and 233nm, it is possible that energy transfer occurs are as follows: Trp→Tb^3＋,Trp→Tb^3＋→Phe,Tb^3＋→Phe,Tb^3＋→Trp.These results indicate that Phe may combine with Tb (Ⅲ).The results of calculations indicate that the distance between Trp and Tb (Ⅲ) is atout 5.56Å.

Abstract:The dioptic system of compound eye of Beijing firefly was simulated on the basis of the real parameters measured from it's structure physiology and it's known GRIN lens properties.The size of the model and values of refractive index were based upon the measured values of actual compoune eye.It was proved that the compound eye of Beijing firefly was a refracting superposition eye by the computer ray tracing model of the compound eye.Parallel light rays incident through the superposition aperture were focussed across the clear zone onto the retina and formed a blur-circle with a certain half-width value. The number of signal light rays and the ratio of signal and noise were increased as the distance to the image plane from exocone proxmal tip were increased. The maxtmun was at the retina level.

Abstract:The different range characteristics of acridine orange in absorption and fluorescence is dependent on its concentrations.The importance and mechanism as well as principles of choosing correct acridine orange concentration and rational amounts of lysosome in the assay of protons pumping are discussed. The obvious influences of the incubation time of acridine orange with lysosome and the K^＋/H^＋ exchange upon the measurements of proton transport are studied.

Abstract:A polyacrylamide gel electrophoresis-stains-all staining assay for terminal deoxynucleotidyl transferase (TdT) activity in purified TdT and leucocytic homogenate of normal and leukemic patients has been developed. The results show that stains-all[(1-ethy1-2-[3-(1-ethyl-naphtho [1,2-d] thiazolin-2 ylidene)-2-methylpropenyl]naphtho [1,2-d]-thiazolium bromide] is highly specific for single strand oligo-deoxynucleotidyl fragment; no other cell component produces influence.The method permits the estimation of TdT activity as low as 3U. It is a simple assay suitable for clinical analysis of TdT in human leukemias and provding information useful in classifying haemaological neoplasms.

Abstract:Research on the determination of phosphorus content in living rabbits by in vivo neutron activation analysis(IVNAA)was carried out,and the average value of the phosphorus percentage content which were measured for ten rabbits was (1.26±0.01)%.

Abstract:PCR-single strand conformation polymorphisms is a powerful method for screening mutations and widely used in studying mutations of oncogene and tumor suppressor gene.The ordinary PCR-SSCP needs the use of radioactivity and sequencing appratus, thus compromises its application.Here,a non-radioaltive asymmetric PCR-SSCP was established.Single-stranded DNA was generated by asymmetric PCR, seperated by mini PAGE and silver stained. The exon 5,6,7,8 of p53 gene in four cell lines of nasopharyngeal carcinoma-CNE1, CNE2, HK1 and SUNE1 were investigated. The method was proved to be succssful in screening mutations.

Abstract:Mycoplasma contamination of cell culture is a serious problem in biomedical reseach. Three common PCR primers(F1,F2 and R1) were designed to amplify the spacer region between 16s and 23s DNA in rRNA operons of 6 species of mycoplasmas (M.arginini,M.orale,M. hominis ,M .hyorhinis,M fementans and A.laidlawii). When the DNA of 6 species was used as the template, primers F1 and R1 produced fragments of 340 to 468 bp,and primers F2 and R1 produced fragments of 145 to 211 bp. No discrete band was observed in electrophoretic gels when Hela cell or E.coli DNA was served as the template with the use of primers F1 and R1. As little as 8.5fg DNA of M.arginini，approximately 1 3 organisms could be detected. This suggests that mycoplasma contamination to cell cultures can be detected by PCR.

Abstract:A method for generating a nonradioactive digoxigenin labeled probes is described.It was achieved by substituting the dTTP with Dig-ll-dUTP and utilizing human genome DNA as template during the Hot Start PCR.