Abstract:Pitx2 is asymmetrically expressed in the left lateral plate mesoderm and derived organs such as heart and gut during chick, mouse and Xenopus development. Pitx2 appears to be downstream effector of Shh and Nodal. Misexpression of Pitx2 is sufficient to produce reversed organs of body rotation. Defect of Pitx2 in human may cause Rieger syndrome. Pitx2 seems to be a key conserved signalling molecules that mediates left-right asymmetry in vertebrate.

Abstract:The glassified proteinaceous bioactive substances are extremely stabilized at room temperature by the presence of the specific carbohydrates as a glass-forming carrier and chaperonins／dehydrins as a protector. There are indications that the natural vitrification of bioactive substances in seed of plant lead the seeds into the dormant phase.

Abstract:Myostatin(Mstn) gene is a new member of the TGF-β superfamily, which is expressed specifically in skeletal muscle and functions as a negative regulator of skeletal muscle growth. Myostatin gene may represent an ideal target for manipulating muscle mass because it is a single gene, the absence of which results in increased muscle mass, and a natural knockout is already present in the existing double-muscled cattle population, suggesting that manipulation of this gene should not interfere with other growth systems and result in abnormal pathology.

Abstract:Many unrelated proteins share identical short peptide sequence but adopt different conformations. Structural transformation that occurs in the process of protein folding and functioning is of great significance in biological organisms. The structural transformation of peptide segment in the process of serpin and EF-Tu inactivation, hemagglutinin activation, protease maturation, subunit assembly and protein amyloidosis is reviewed and its implication for the understanding of protein folding and “conformational diseases” is also discussed.

Abstract:Insulin is one principal hormone in mammals. It modulates the process of metabolism and promotes cellular growth and differentiation. Its action is mediated through insulin receptor. Insulin binding activates the tyrosine kinase activity of the receptor. The activated receptor frequently undergoes autophosphorylation and then phosphorylates cellular signal molecules, thus making it possible for insulin to elicit the corresponding response. A brief description is given on the process of signal transduction in the cell after insulin stimulation and the cellular signal molecules involved in the process.

Abstract:Receptor tyrosine kinases (RTKs) are involved in many different processes including cellular growth，differentiation,embryonic development，oncogenesis and intracellular signalling pathways, thus possessing important physiological functions. There are now more than 50 distinct RTK genes that have been published and divided into 14 sub-families ,the largest one known is the Eph sub-family which is comprised of at least fifteen members. Some of the Eph family members are predominantly expressed in the developing brain, the others are expressed in a broader range of tissues. Recently the findings of the excellular ligands of this family should facilitate further studies of its function. The isolation, pattern of expression and the ligands of Eph-like receptors are summarised.

Abstract:Some genes express only one allelic gene and the another allelic gene is specifically inhibited through some kinds of gene modification. Those genes are called imprinted genes, and they are a unique model of allelic exclusion. Most of imprinted genes participate in regulating development and differentiation of embryo and newborn infant, and disorder of imprinting function may results in many kinds of abnormal development and stilbirth. The mechanisms for the formation of imprinted genes, specific recognization and the defect of imprinting function are still not very clear.

Abstract:Bioinformatics is one of most active fields in life science. In recent years, various bioinformatics databases have appeared. The size of the database has grown explosively, and the structure of database has been more complex. Now most databases are severed through the internet. The progress in algorithm and software, integration of database and server-client structure make bioinformatics the powerful tool in biology, medicine and agriculture. In 1996 the first network-based bioinformatics server in China was established in Institute of Physical Chemistry, Peking University. Via the Internet, more than 70 000 scientist from all over the world have been served by the server.

Abstract:C/EBPs are a group of heat-stable transcription factors which function extensively. They not only involved in normal process of physiological metabolism but also are related to the occurrence and development of many kinds of disorders. C/EBPs have multiple modes in which they act as activator or inhibitor in regulating transcription. All these various functions of C/EBPs are related to their special structures that characterize the members of bZIP family.With themselves or other isoforms, C/EBPs can form homodimers or heterodimers that contain different regulational informations.Furthermore, they can interfere with a wide variety of protein factors, thus the mode and specificity of the functions of C/EBPs are determined.

Abstract:Nitric oxide( NO) is a ubiquitous and unique biological messenger molecule and effector.Discoveries have been made regarding the physiologic and pathologic roles of NO in the nervous system.Effects of NO have been identified on neurotrans-mitter release,neural morphogenesis,regulation of gene expression and cerebral blood flow.NO may play a role in long-term potentiation of synaptic transmission in the hippocampus and long-term depression of synaptic transmission in the cerebellum as a retrograde messenger.Excessive production of No is neurotoxic and is implicated in a variety of neurological disorders.

Abstract:Calponin cDNA was site-mutated (Thr184→Ala184) by overlap extension PCR method to reduce the opportunity for calponin to be phosphorylated by PKC or CaMKⅡ. The PCR product was sequenced. The mutated cDNA was then recombined into an expression vector pAED₄ and transferred into, expressed in E.coli BD₂₁(DE₃) induced by IPTG. The expression level was up to 15% of total bacterial proteins. Mutated calponin was liberated form E.coli by freezing and thawing and purified by Sephadex G-50. The recombinant protein and the purified mutant protein was identified by Western blotting.

Abstract:The genes effecting in the process of the apoptosis of TF-1 cell line when it is deprived of the cytokine in the culture medium were studied by RDA (representational difference analysis) method. The TF-1 cell depriving of cytokines for 8 hours was selected as the Tester and normal-cultured TF-1 cell as the Driver. Seven gene fragments were found uniquely expressed or highly expressed in the process of apoptosis of TF-1 cell line which include some known genes such as Hou and thioredoxin that formerly suggested to play a role in apoptosis.There are three fragments are complete novel after searching the nr and EST catalogues of GenBank and were banked into GenBank. The accession numbers for them are U83208, U83279, U83397 respectively. From the novel gene fragments, the complete cDNA sequence of them can be fished and the bioactivity and function of them in apoptosis of TF-1 cell and other hematological tumors can be further studied. On the other hand, the function of some known genes which were not suggested formerly in the course of apoptosis can be studied.

Abstract:The changes of proton-translocation across the inner mitochondrial membrane of hepatocytes in endotoxic shock rats were studied.It was showed that: Five hours after shock, the maximum value of fluorescent quenching（ΔA_max）of ACMA(9-anmino-6-chloro-2-meto-acridine) induced by ATP,NADH and succinate was significantly decreased (P＜0.05). The time of maximum fluorescent quenching（T_ΔAmax）and the time of half maximum fluorescent quenching（T_1/2ΔAmax）were significantly prolonged (P＜0.01). It was suggested that the ability of proton translocation across the IMM in endotoxic shock rats was decreased. The membrane fluidity were significantly decreased at the deep level and hydrocarbon chain. The mitochondrial membrane-associated PLA₂ activity, plasma MDA,and mitochondrial MDA contents were significantly increased in endotoxic shock rats. The results showed that PLA₂, and lipid peroxide may be the causes of the changes of proton translocation in endotoxic shock rats.

Abstract:Hepatitis C virus has four chief genotypes HCVⅠ、Ⅱ、Ⅲ and Ⅳ,whose homology of amino acids and nucliec acids is less than 80% each other.The variation rates of HCV proteins are core 8%，E1 35%，E2/NS1 53%，NS3 27%，NS4 35%，NS5 39%，respectively. According to the characters of conservation, hydrophilicity, antigenicity and conformation,a series of highly conserved T cell and B cell epitopes are identified from the HCV expressed products,which might be benificial to the prevention and treatment of hepatitis C.In genenal, B epitope is about 12～40 peptides and T epitope 7～9 peptides.

Abstract:Two polysaccharides which were prepared from Chinese traditional medicine Ruoye (Indocalamus tesselatus), a kind of bamboo leaves by alkaline extraction were studied. Their physicochemical properties and structural feature were elucidated by modern analytical technique such as IR, NMR, GC, partial acid hydrolysis, periodate oxidation and Smith degradation. The typical absorptions of these polysaccharides were shown in IR spectra. The main structure was examined: FⅢ-a, (1→6)-β-D-galactosyl branched (1→3)-α-D-Xylan and FⅣ-a, (1→6)-β-D-galactosyl (1→3)-α-D-Xylan with arabinose branches at C-6 position.

Abstract:A magnetic immobilized glucoamylase has been prepared by adsorbing glucoamylase onto a magnetic collidal particle and cross-linking it with glutaraldehyde.The effects of different concentration of glutaraldehyde,pH of buffer,and the amount of glucoamylase on immobilization. The results showed that the activity of MIE was 17 095 U／g dry gel.The activity recovery was 63%. And some properties of magnetic immobilized and native glucoamylase such as optimum temperature、optimum pH and michaelis constant、stabilities to heat and operational stability were studied and compared.

Abstract:The interactions between M-CAT binding factors (MCBFs) in nuclear extracts from developing chick tissues with oligonucleotides containing CATTCCT or CATTGCT core sequence were analyzed by gel retardation and Southwestern blot. Gel retardation assays showed that binding activities of MCBFs expressed in all tested organs, including skeletal muscle, cardiac muscle, gizzard, liver and brain, whereas the binding patterns were different between five tissues. Also, the binding patterns of CATTCCT and CATTGCT core sequence-containing oligonucleotides respectively with MCBFs in skeletal muscle extracts were different from each other. Southwestern blot analysis indicated that a 30 ku MCBF existed in the extracts from five tissues of chicken embryos by using oligonucleotides containing either CATTCCT or CATTGCT core sequence as a probe, suggesting that 30 ku molecule is an ubiquitous factor expressed in all tissues and this molecule can bind to both oligonucleotides in the manner of monomer or/and dimer and polymer. These imply that 30 ku molecule is essential for MCBF binding activities. Besides the ubiquitous factor, the possibility of specific factor(s) interacting with 30 ku molecule to form a heterodimer to bind to DNA can not be excluded. The ubiquitous factor of 30 ku expressed in skeletal muscle during embryonic development and disappeared after birth.

Abstract:A receptor for murine granulocyte colony-stimulating factor (G-CSF) has been found on the cell surface of mouse myeloid leukemia cell line NFS-60. By large scale culture of NFS-60, The receptor in the membrane fraction of NFS-60 cells were solubilized in an active form with CHAPS, The receptor was obtained by centrifugation at 150 000 g for 90 min, The solubilized receptor was purified nearly to homogeneity by a G-CSF affinity gel. The purified receptor has been identified with the method of ABC-ELISA.

Abstract:Hydroxyl radicals produced in Fenton reaction can react with dimethyl sulfoxide to produce methane sulfinic acid which can further react with Fast Blue BB salt to form light yellow diazosulfone. According to the principle, hydroxyl radicals can be indirectly assayed by colorimetry. The determination condition was studied to obtain a best experimental program. The results showed that the hydroxyl-radical-scavenging effect were dose dependent upon thiourea and ascorbic acid. The walnut and black sesame were proved to be natural anti-oxidation foods. The method can be applied to sieve the hydroxyl radical scavenger.

Abstract:Recombinant plasmid PBV-SCF was transformed into the DH5α and a high expressing germ that could produce about 20 percent SCF product of all the bacterial protein was selected. The SCF product is expressed in form of inclusion body. By liquid chromatography, recombinated human SCF(rhSCF) was obtained with the purity of 90 percent. The sequence of the N-terminal amino acid and the isoelectric point of the rhSCF were analyzed. They are same as the natural SCF. The specific activity of the rhSCF is 6.6×10⁵ U/mg.Morcover, it can coordinate with the granule-macrophage stimulating facet (GM-SCF) to stimulate proliferate of the CFU-GM from the human bone marrow. The acquiration of the rhSCF is important to both the labotory research and the clinical therapy.

Abstract:A TRAP assay on human colonic tumor telomerase activity is reported. The reliable result is obtained when 1.8 mmol/L Mg²⁺ and 55℃ annealing temperature are adopted. The other two factors affecting reliability are quantity of the extract and contamination of the positive DNA fragments in the reaction.

Abstract:RP-HPLC method with a simple “MeOH-H₂O-TFA” elution system is applied in purification and analysis of human glycoalbumin fragment including the region of lysine 525, which was synthesized by different methods. The peptide fragment of albumin KQTALYYC prepared by acid-labile PEG resin was glycosylated and purified by gel filtration and analysed by RP-HPLC. A single peak demonstrated that the glycosylation of the peptide was successful. Heptapeptide fragment of albumin QTALYYC was synthesized by chloromethyl resin according to the Boc chemistry strategy. The pure heptapeptide was obtained by semi-preparative RP-HPLC. Glycosylated lysine was purified by gel filtration and ascertained by RP-HPLC. The heptapeptide was coupled with glycosylated lysine. RP-HPLC of the product showed that the glycopeptide is qualified as a semiantigen.

Abstract:The transport-competent plasma membrane vesicles were obtained using a modified homogenization medium by the two-phase partitioning method from soybean hypocotyls. It was noted that freeze-thaw treatment could increase the amount of inside out vesicles.Further experiments showed that the fluorescence quenching caused by adding of Mg^2＋-ATP could be dissipated by the proton ionophore CCCP, and inhibited by the proton transport inhibitor DCCD; it was also found that the plasma membrane H^＋-ATPase specific inhibitor vanadate could quench the fluorescence completely. The fluorescene quenching was Mg²⁺-dependent, K^＋-stimulated, with an optimum pH of 6.5. All the above results indicated that the fluorescence quenching was caused by the transport of protons by the plasma membrane H^＋-ATPase. It was also suggested that the maintaining of suitable conformation of the plasma membrane H^＋-ATPase,and the tightness of plasma membrane vescials are the two key factors for the proton transport determination.

Abstract:A new method was described which allowed the analysis of sialic acids in glycoproteins at femtomole. Sialic acids released from recombinant human erythropoietin(rhu-EPO), human urine trypsin inhibitor(h-UTI) and bovine α₁-acid glycoprotein(α₁-AGP) by acid hydrolysis, were derivatized with 2-aminoacridone(AMAC), and then separated by capillary electrophoresis, separately. The quantities of sialic acids in the first two glycoproteins were consistent with the previous results while inconsistency was found in the bovine α₁-AGP case. It was found that in bovine α₁-AGP N-glycoloyneuraminic acid (Neu5Gc) was present in addition to Neu5Ac with a quantity comparable to that of Neu5Ac. Based on these data, the AMAC-derivatized sialic acids were unstable and could undergo a decarboxylation reaction at room temperature under light, but they were stable at －20℃in the dark for at least 12 h.

Abstract:Giant panda brain CaM was purified by Phenyl-Sepharose CL-4B hydrophobic chromatography and FPLC. The results of SDS-PAGE, PAGE and IEF indicate that the protein has been purified. The molecular weight and PI of CaM are 19 ku and 3.8, respectively. Giant panda brain CaM shows calcium ion effect in SDS-PAGE and PAGE. It can activate bovine heart PDE. The result of amino acid composition of giant panda brain CaM is similar to CaMs from other sources.

Abstract:An allele-specific amplification based PCR method was built up for the detection of CYP2D6T allele which is a 1 795 T deletion on CYP2D6 gene and results in a function deficient enzyme. This method was employed to genotype 396 subjects and proved to be simple, quick and less contamination. It has made a basis for this detection a clinical tool.