Abstract:Calmodulin is currently regarded as a central component in a complex regulatory system in the eukaryotic cell and imposes control upon many of the essential metabolic and physiological functions of the cells.But the attempts to find such calmodulin-like-protein in prokaryotes always gave controversial condusion before. Since the first calmodulin-like-protein was found in E. coli in the early 1980s,the protein factors have been detected in many kinds of prokaryotes,and their regulatory functions have been found in sporulation, cell fission of bacteria, heterocyst cyto-differentiation, N₂ fixation and photosynthesis in cyanobacteria etc. The recent research progress in the field was reviewed.

Abstract:Recently the research for cell cycle regulation has been made a great prograss. People have gone deeply into the cyclin family and p³⁴ family to find out their regulation functions in cell cycle and the relationship between them. Simultaneously,many regulation factors which are related with them have been found.All these factors interact to form a very complicated cascade regulation network.

Abstract:To study the reaction mechanism of lipid peeroxidation,methodology is of critical importance.Many methods have been used to measure lipid peroxidation in biological systems,but every one has some advantage and also some disadvantage in different experiments. Recently people often use some advanced methods,such as high-performence liqid chromatography(HPLC),chemiluminescence and so on.

Abstract:Pseudomonas aeruginosa exotoxin A(PE)contains three structure function domains. The amino-terminal domain Ⅰ is involved in binding to target cell-surface receptors through the active site Lys57.The central domain Ⅱ is responsible for the translocation of PE across membranes,Arg276 and Arg279 are the active key positions of the domain Ⅱ.The protease cleaves PE between Arg279 and Gly280 into 28 000 and 37 000 fragments. The carboxyl-terminal domain Ⅲ is located in 37 000 fragment which is directed by the REDLK sequence at the carboxyl end of domain Ⅲ to the endoplasmic reticulum and translocated to the cytosol, and then ADP-ribosylates the EF-2 (elongation factor 2) by binding NAD⁺ through the key site Glu553 to result in the inhibition of cell protein synthesis and death of target cells. It is a practical prospect that the recombinant immunotoxins are made by fusing DNA fragments encoding recognition proteins to the modified PE genes.

Abstract:Bacteriorhodopsin is a kind of photo-energy conversion protein existing in the purple membrane of halobacterium halobium.It serves the function of photochromic materials and light-driven proton pumps,with an extremely fast primary photo-isomeric process occurring within 430ps. On account of the fact that bacteriorhodopsin has a series of unique photoelectrical and optical properties such as differential responsivity to light intensity,high spatial resolution,high photosensitivity,high cycling,etc.,it has found many important applications in photoelectrical detection. visual simulation system, artificial neural network, nonlinear optics and optical information recording and processing. Depended on the techniques of ultrafast pulse laser, highly time-resolved spectroscopy and high speed sampling detection. studies on bacteri-orhodopsin' s photocycle, primary photo-iso-merization，excited state dynamics，lightdriven proton pump mechanism and other aspects have been successfully developed with many significant results.

Abstract:FISH is a new technique which is used to localize a specific sequence on chromosome,It has been widely used in the research of human genome project.With FISH,a SCP,a cosmid or a YAC can be localized on the metaphase chromosome,and a chimeric YAC can also be identified.Gene mapping can be done at the resolution of 50 kb with FISH on the interphase nuclei.Now FISH of a gene on the strechted chromatic fibre can be done,the length of the gene can directly be measured and the gene can be localized at high resolution. In a word. FISH is playing a more and more important part in the human genome research.

Abstract:Finding transcribed sequences from specific genomic regions has been a major ratelimiting step in cloning genes involved in human genetic diseases. Early efforts was focused on screening of cDNA library,looking for evolutionarily conserved DNA sequences and northern blot hybridization. In resent years,some new and effective methods have been developed by the Human Genome Project.These methods can not only detect genes regardless of their expression patterns,but also expand the size of the genomic region capable of being scanned for genes. Several new and old methods for were reviewed finding new genes in positional cloning and discuss the advantages and limitations of them.

Abstract:Being as an efficient expression vector,baculovirus is now being used to express a wide variety of genes from viruses,fungi,plants and animals. However,some short-comings,such as low efficacy of homologous recombination and difficulty as well as long time consumed in puirfication of recombinant baculoviruses,accompany the traditional method of constructing a recombinant baculovirus. To overcome the shortcomings,some new and efficient techniques,including linearizing viral DNA to increase the ratio of recombinant baculoviruses recombinating foreign genes in vitro. completing homologous recombination and selection of recombinant viruses in yeast and in E. coli, and making recombinant viruses to produce polyhedra, have been developed in recent years to construct the recombinant baculoviruses rapidly and conveniently. These improved methods are. therefore. to be described.

Abstract:The activity of mushroom tyrosinase catalyzing the conversion of o-diphenols to o-quinones in organic solvents has been investigated with addition of different amounts of water and at various temperatures. The results have shown that tyrosinase possesses high activity in organic media,the enzyme activity is mainly controlled by the water activity in the reaction system,and it can increase with the increase of reaction temperature as long as the amount of water bound to the enzyme molecule is properly controlled. Salt hydrates are effective for such control in nearly non-aqueous conditions.

Abstract:The striking distinctions of oximes. such as 2-PAM,LuH6,TMB₄ and HI-6. in reactivating sarin-,soman-,tabun- and VX- phosphorylated acetylcholinesterase (AChE) imply that there are factors which hinder phosphorylated enzymes from being reactivated by some oximes before aging. To investigate this phoblem,a comparison of in vitro reactivation of these phosphorylated enzymes by H series oximes,HI-6,HGG-42 and their 4-oxime isomers.was made. Results showed that,in tabun experiments,although there was no reactivation by the two 2-oximes (HI-6 and HGG-42)，28%-45% reactivations were observed by their 4-oxime isomers. In soman case the results were opposite. HI-6 and HGG-42 showed remarkable reativation. but their 4-oxime isomers were ineffective. For sarin- and VX- phosphorylated AChE, all oximes showed high effctiveness. These results indicated that there are conformational differences among the active centre of the above phosphorylated enzymes. The influences of AChE allosteric agents showed that C₁₀ significantly increased the effects of TMB₄ in sarin, soman and VX experiments, however. it reduced the effect of TMB₄ significantly in the tabun case. Propidium has no influence on the reactivation of sarin, soman- and VX-phosphorylated AChE, but it significantly reduced the effect of TMB₄ on reactivating tabun-phosphorylated enzyme. These results confirmed that the conformation in the active centre of tabun-phosphorylated enzyme is obviously different from that of sarin-，soman- and VX- phosphorylated enzymes.

Abstract:The ras P²¹ expression in non-cancer lesion and carcinomas of the stomach was quantitativaly studied by flow cytometry,and relation of ras P²¹ expression to DNA ploid and cellular proliferation index were inquired.The results showed that ras P²¹ expression was higher in carcinomas than in non-cancer lesion one’s of thee stomach.In non-cancer lesions,ras P²¹ expression in precancer lesion was higher than in chronic atrophic gastritis,and the raiser of fluorescence index in ras P²¹ expression was found with raiser of histological grade. DNA ploid was associated with ras P²¹ expression.

Abstract:In order to study the oncogenic effects of EB virus latent membrane protein,the putative oncogene product encoded by EB virus BNLF1 gene,The MT-BNLF1 gene containing the promoter of the mouse metallothionein-1 gene fused the structural gene of EBV BNLF1 gene was constructed.This gene was microinjected into the pronuclei of fertilized mouse eggs to bulid up a transgenic mouse line. The results were as follow(1).The zygote′s survial rate and birth rate were 73% and 13%,respectively.(2) After analysing the mice that developed from the microinjected eggs by southern hybridization and PCR. 8% mice carry MT-BNLF1 fusion gene. This approach was a preliminary attempt to study the onset mechanism of the nasopharyngeal carcinoma.

Abstract:A new method for measuring the anion transport activity of Band 3 in the erythrocyte inside-out vesicles(IOVs)was presented.Impermeable IOVs containing 80mmol/L dipicolinic acid (DPA)were obtained by pressing the IOVs through a No.9 gauge needle in DPA- containing medium.Efflux of DPA from the IOVs into Tb³⁺-containing transport buffer was monitored fluorometrically. The technique is highly sensitive, reproducible and much convenient as well.

Abstract:The direct and the indlrect fluorescent labeling are two different staining methods in immunofluorescent measurement.In flow cytometer measurement,in general,the direct labeling has little nonspecific binding and disturbance,and the experiment data is easy to process.However,because of the magnifying function,the indirect labeling has much nonspecific binding and serous disturbance. It is difficult to distinguish the specific signals from non-specific ones,it is easy to cause confusion in data processing. By comparing samples，the direct labeling is suggested better than the indirect labeling in flow cytometer measurement.

Abstract:The aqueous solution of the silk fibroin from silkworm Bombyx mori cocoons was obtained by treatment of the neutral salt (CaCl₂). Peroxidase(POD)was immobilized in the silk fibroin membrane. Activity and characteristics of the POD-immobilized fibroin membrane were analysed.The results show that the activity of the POD-immobilized membrane is high;Optimum pH range for the enzyme membrane,being at pH5.0-7.0,was widened in comparison with the free enzyme;and its thermal stability was good.

Abstract:Based on the mode of formation of microsomal lipid peroxdation induced by Fe²⁺/cysteine and the principle of TBA reaction,a simple one-step microassay for the studying and screening of antioxidants in 96-wells plate was established. The comparative studies between the procedures in 96-wells plate and in test tube were also conducted.This microassay requires only small volume of diluted microsome and tested compounds,having the advantages of reliability,rapidness,simplicity and convenience. It is especially suitable for the pilot screening of antioxidants as well as the simultaneous study for many samples. This method can also be used to measure the lipid peroxidation induced by other systems.

Abstract:Urinary microalbumin was detected by an autoanalyzer with the method of immunoturbidimetry. The spot urine samples from a group of 140 healthy subjects were determined to establish a reference range of urinary microalbumin excretion rate(confidence interval 95%)and its upper limit was 2.83 g/mol creatinine. This assay and the urinary enzyme(N-acetyl-beta-D-glucosaminidase,NAG)determination were applied in the patients with diabetes mellitus and with hypertension for detecting the incipient nephrological changes. The results showed that this index was sensitive to detect the early elevation of albumine excretion in urine and has been proven to be a more valuable diagnostic tool in the early diagnosis of renal damage than the tradtional urine protein test. As the urinary lysosome enzyme (e.g.NAG) is more specific and sensitive marker of renal tubular injury. it is suggested to combine the microalbumin and the enzyme assays to yield more valuable informations. The serum type Ⅳ collagen determination with the enzyme immunoassay was performed simultaneously in the same group of patients with diabetes mellitus. It was found that the mean value of serum type Ⅳ collagen was higher than that of the control group. This index indicated the dynamic process of collagen peptide synthesis occurred in the basement membrane.

Abstract:An agarose gel electrophoretic method for separating creatine kinase (CK) isoenzymes and its isoforms(CK-MB and CK-MM isoforms)simultaneously was established.It is based on a suitable discontinuous buffer system.By passing a larger current through the gel under a lower applied voltage, the separating time was shortened to 30 min. The measurements of CK-MB%,CK-MB₁%,CK-MB₂%,CK-MM₁%,CK-MM₂%,CK-MM₃% can be completed within one hour. The method is sufficinently sensitive to detect the CK-MB isoenzyme and CK-MM isoforms at the concentration of lowest detection limit 2.2U/L and 32U/L respectively. Thus, this system can be used to rapidly, sensitively and precisely quautify the isoenzymes and isoforms of CK.

Abstract:Recent study indicated that camphorm,a new ribosome-inactivating protein (RIP),contained only one tryptophan residue. This single tryptophan residue had obviously different relation with the three enzymatic activities of camphorin.

Abstract:An“electron leak route” is suggested to be present in the respiratory chain in mitochondria. The route consists of electron leaks:the one on the substrate side produces O2·- and H2O2,while that from one on the substrate side actually reduces H2O2 to H2O。Therefore,the “electron leak route”is actually function as a way of oxygen radical metablism. The O2·--conumption by the“electron leak route”is insensitive to KCN,and therefore can be considered as a way of non-phosphorylative respiration of mitochondria.

Abstract:Day-night variation of the content of CREB in the suprachiasmatic nucleus was analyzed in male Wistar rats maintained under light-dark cycles and constant dark by gel-mobility shift.It was found that the CREB in the SCN has endogeneous circadian rhythm.

Abstract:Animal and plant calmodulin were conjugated successfully with the emission substance,N-(4-aminobutyl)-N-ethyl-isoluminol(ABEI)by the method of carbodi-imide condensation.The labelling rate of[ABEI]/[CaM] is 0.8-0.9.The reacting condition of CaM with ABEI,the quality and the keeping time of the ABEI-CaM conjugate were observed.The conjugate was stable and can be kept more than 10 months at -20℃. It was suitable for the chemiluminescent immunoassay in which the level of CaM in the biological sample was measured.

Abstract:Human fresh livers were treated by homogenization and centrifugation,then were purified by sephadex-G200 column chromatography,DEAE cellulose column chromatography,and polyacrylamide gel electrophoresis,pure human liver F antigen was obtained.Specific antisera were prepard by immunizing guinea pigs with the purified human F antigen.

Abstract:A modified method of poly (A) RNA purification using oligo(dT)cellulose is described. The purification can be done in tip with cellulose,which consists of only 1/50-1/100 of the usual amount used.Contrast with the typical methods,it not only has the adventages of shorter experimental time and higher proportion of mRNA production, but can also produce mRNA which can be used as template of cDNA synthesis directly.