Science in China. Series B, Chemistry, life sciences & earth sciences (Sci China B Chem Life Sci Earth Sci )

Publisher: Zhongguo ke xue yuan

Description

Science in China is a comprehensive academic journal of natural sciences sponsored by the Chinese Academy of Sciences. The primary purpose is to provide regular, rapid, and authoritative reviews of current important developments in scientific research in China for scientific workers in both China and other countries. The contents are selected by an extensive editorial committee which is composed of the most highly esteemed scientists in China today. This journal is published in five series. Series A (monthly) covers the following areas: mathematics, physics, astronomy; Series B (bimonthly) carries papers on chemistry; Series C (bimonthly) carries papers on life sciences; Series D (monthly) carries papers on earth sciences; Series E (bimonthly) carries papers on technological sciences; and Series F (bimonthly) carries papers on informatics.

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  • Website
    Science in China - Series B: Chemistry, Life Sciences & Earth Sciences website
  • Other titles
    Zhongguo ke xue., Science in China. Series B, Chemistry, life sciences & earth sciences, Chemistry, life sciences & earth sciences, Chemistry, life sciences and earth sciences
  • ISSN
    1001-652X
  • OCLC
    19908874
  • Material type
    Periodical
  • Document type
    Journal / Magazine / Newspaper

Publications in this journal

  • Science in China. Series B, Chemistry, life sciences & earth sciences 01/2010; 53:1932-1936.
  • Science in China. Series B, Chemistry, life sciences & earth sciences 02/1996; 16(2):42-44.
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    ABSTRACT: Previously, it has been found that glucocorticoid receptor (GR) binding activity decreased rapidly during heat shock response in HOS-8603, a human osteosarcoma cell line. In this study, The relationship between the induction of heat shock proteins (HSPs) and the decrease in GR was further studied in the same cell line. It was found that even though quercetin could specifically inhibit the expression of hsp90 alpha and hsp70 mRNA, it could not prevent GR from the decrease in response to the heat shock treatment. This represents the first reported evidence that the induction of HSPs and the decrease in GR during heat shock response were 2 independent biological events. The results of the present study further showed that although the heat shock treatment alone had no effects on alkaline phosphatase (AKP) activity, it could completely block the induction of AKP activity in HOS-8603 cells by dexamethasone (Dex), a synthetic glucocorticoid. These results demonstrate that the heat shock-induced alteration in GR was accompanied by a decrease in GR functional activity. Furthermore, when the induction of HSPs was inhibited by the treatment of cells with quercetin, the stimulatory effects of Dex on AKP activity could still be inhibited completely by the heat shock treatment. The results of this part, on the basis of GR functional activity, further demonstrate that quercetin could not inhibit the heat shock-induced decrease in GR even though it could inhibit the induction of HSPs. To clarify further the effects of quercetin alone on GR binding activity in HOS-8603 cells, the regulation of GR by quercetin was also studied. It was found for the first time that quercetin could down-regulate GR in a time-dependent manner significantly, and that the down-regulation of GR by quercetin in HOS-8603 cells paralelled with a decrease in glucocorticoid-mediated functional responses, suggesting that the down-regulation of GR by quercetin is of biological significance.
    Science in China. Series B, Chemistry, life sciences & earth sciences 01/1996; 38(12):1473-81.
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    ABSTRACT: The binding of bisantrene to four DNA tetramers, d(CGCG)2, d(GCGC)2, d(CATG)2, and d(GTAC)2, was investigated by 1D and 2D NMR spectroscopy. Bisantrene is a well known anticancer drug and has been used clinically for years. DNA is believed to be one of its cellular targets. Results from both 1D and 2D 1H NMR are in agreement with an intercalation binding mode of bisantrene with the four DNA tetramers in this study. The results further indicate that a threading intercalation binding mode, in which one bisantrene side chain is in the minor groove and the other in the major groove of DNA, is preferred. The NMR results also suggest that bisantrene prefers binding at pyrimidine-(3',5')-purine intercalation sequences rather than at purine-(3',5')-pyrimidine sequences. The intramolecular and intermolecular NOE contacts of bisantrene-DNA tetramer complexes indicate that a C2'-endo uniform sugar pucker, rather than a mixed sugar conformation, is preferred by the intercalation site of both the 5'-(TA)-3' and the 5'-(CG)-3' binding steps.
    Science in China. Series B, Chemistry, life sciences & earth sciences 01/1996; 38(12):1462-72.
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    ABSTRACT: The melatonin binding sites in membrane preparations of the mouse thymus were demonstrated using 2-[125I] iodomelatonin as a radioligand. The binding sites were stable, saturable, reversible and of high affinity. Studies on specificity of 2-[125I] iodomelatonin binding suggested that the 2-[125I] iodomelatonin binding sites are highly specific for melatonin. These binding sites fulfilled the standard criteria for receptors. Our work suggested that melatonin should have direct regulatory action on immune system mediated through the melatonin binding sites. Studies on the circadian rhythm showed that there existed the circadian rhythm in the binding capacity for 2-[125I] iodomelatonin in the mouse thymus with the peak values at 12:00-16:00 and the trough values between 00:00 and 4:00. The subcellular distribution of 2-[125I] iodomelatonin binding sites in the mouse thymus was in the following descending order: nuclear > mitochondrial > microsomal > cytosolic fraction. There was also an age-related decrease in 2-[125I] iodomelatonin binding in the mouse thymus. This is correlated with the involution of the thymus.
    Science in China. Series B, Chemistry, life sciences & earth sciences 12/1995; 38(12):1455-61.
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    ABSTRACT: Three tissue-type plasminogen activator (t-PA) mutants were constructed by recombinant and site-directed mutagenesis techniques. They are del(296-302) with deletion of PAI-1 binding site, N117Q/N184Q with deglycosylation of K1 and K2 domains, and their combination mutant designated as GGI. Then these three mutants were successfully transiently expressed in COS-7 cells, and GGI was further stably expressed in CHO cells. The biological characterization of the expression products indicated that del(296-302) and GGI possessed the resistance to inhibition by PAI-1. In addition, the specific activity of GGI was increased by about 46%, the plasma half-life was prolonged by about one fold, while its affinity for fibrin was not affected.
    Science in China. Series B, Chemistry, life sciences & earth sciences 12/1995; 38(11):1341-8.
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    ABSTRACT: The ligand-binding region of human IL-6R is taken as the target gene fragment to be cloned and expressed. With pET-3b as expressing vector, two recombinants pET-6R(B) and pET-6R(B)4 have been constructed encoding the ligand-binding region (28 kD) of hIL-6R and its dimmer (53 kD), respectively. After induction with IPTG, they produced two proteins rIL6R-28 of 28 kD and rIL6R-53 of 53 kD amounting to 50% and 30% of total bacteria proteins, respectively. The expressed products were mainly recovered as inclusion bodies. After purification and renaturation, both of them were capable of augmenting the growth-stimulating effect of IL-6 on 7TD1 cells, an IL-6 dependent cell line. The result of ELISA also revealed that both rIL6R-28 and rIL6R-53 had the obvious ligand-binding activity.
    Science in China. Series B, Chemistry, life sciences & earth sciences 12/1995; 38(11):1321-31.
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    ABSTRACT: Life is a continuous process of the dynamic metabolism. The influence of electromagnetic waves on the process of metabolism cannot be neglected. Here a new theory of electromagnetic interference in the dynamic metabolism of life is proposed. The statistical dynamic equations of ion and free radical in the biochemical reaction radiated by electromagnetic waves are given. The intensity of electromagnetic interference could be described with an interference factor. Good agreement can be seen between the calculated and measured results for a famous experiment of radio-frequency radiation-induced calcium ion efflux enhancement.
    Science in China. Series B, Chemistry, life sciences & earth sciences 12/1995; 38(11):1355-60.
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    ABSTRACT: The genomic library of Kluyveromyces fragilis was constructed in E. coli TG1, and 5 beta-galactosidase gene (LAC4) clones have been obtained from the library by complementation of the Kluyveromyces lactis lac4-8 mutation. The studies on the structure and the function of the LAC4 gene revealed that (i) the gene can also complement E. coli lacZ mutation; (ii) the physical map of the K. fragilis LAC4 gene was very similar to that of K. lactis; (iii) the beta-galactosidase levels expressed by the clone strains were much higher than that expressed by the original strain; (iv) the variation of the beta-galactosidase level of different clone strains induced by lactose or galactose was related to the retained degree of the 5' flanking region of LAC4 gene, suggesting that there might be a lactose specific transcription activating element in the region.
    Science in China. Series B, Chemistry, life sciences & earth sciences 12/1995; 38(11):1332-40.
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    ABSTRACT: A 551-bp hIL-11 gene fragment that includes no nucleotide sequences encoding signal polypeptide and the initial 8 amino acids of the mature protein was cloned into a high-level expression vector pEx31B of E. coli. The authors identified the recombinant plasmid, designated pEx31-IL11, by restriction endonucleases digestion and DNA sequencing. The resulting recombinant plasmids were then used to transform E. coli strain HB101, and expression in the PL promoter system, which is temperature-regulated, was achieved. The expressed fusion protein amounts to 50% of total bacterial proteins. The hIL-11 protein expressed in E. coli was fused to the N-terminal 99 amino acids of the MS2 polymerase to form the inclusion body. These recombinant proteins can be purified to about 80% by extracting inclusion body with urea. One IL-6-dependent cell line 7 TD1 was used for bioassay. The recombinant hIL-11 protein was preliminarily purified and renatured to a specific activity of 10(5)U/mg, even in the presence of an excess of a neutralizing anti-IL-6 antibody.
    Science in China. Series B, Chemistry, life sciences & earth sciences 11/1995; 38(10):1202-9.
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    ABSTRACT: The levels of DNA polymerase alpha, delta, epsilon were examined in the neonatal mouse forebrains and spleens. The levels of DNA polymerase alpha were determined by the difference of polymerase activity in the absence and the presence of alpha specific inhibitor, BuPdGTP, or its monoclonal antibody. The levels of DNA polymerase delta were determined in H.A fractions after separating it from the other two enzymes. The levels of DNA polymerase epsilon were identified in H.A fractions by the use of alpha-monoclonal antibody or BuPdGTP. Results showed that in the mouse forebrain DNA polymerase alpha, delta, epsilon activities are the highest before birth, decline sharply following birth and are very low on the 8th day and hardly detectable on the 17th day; as for the mouse spleen, however, DNA polymerase alpha, delta, epsilon activities are the lowest at birth, increase rapidly after birth and reach their maxima on the 8th day and then decline gradually but remain in higher levels. These results not only prove that DNA polymerase alpha and delta take part in cell DNA replication but also suggest that DNA polymerase epsilon is involved in DNA replication.
    Science in China. Series B, Chemistry, life sciences & earth sciences 11/1995; 38(10):1237-45.
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    ABSTRACT: The optical recording of three-dimensional (3-D) reconstruction of CA1 pyramidal cells was derived from the studies on the CA1 region of the hippocampus in adult male Wistar rats. The recording was produced by the Confocal Laser Scan Microscope (LSM-10). The attemption was to outline the morphological neural network of CA1 pyramidal cells organization, following the trail of axo-dendritic connections in 3-D spatial distributions among neurons. The fractal structure of neurons with their dendritic and axonal trees using fractal algorithm was noticed, and 2-18 simulated cells were obtained using PC-486 computer. The simulational cells are similar in morphology to the natural CA1 hippocampal pyramidal cells. Therefore, the exploitation of an advanced neurohistological research technique combining optical recording of the LSM-10 and computer simulation of fractal structure can provide the quantitative fractal structural basis for chaosic dynamics of brain.
    Science in China. Series B, Chemistry, life sciences & earth sciences 11/1995; 38(10):1187-94.
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    ABSTRACT: A series of t-PA cDNA mutants containing different parts of 3'-UTR sequences have been constructed. In vitro translation of t-PA transcripts in rabbit reticulocyte lysates and its expression in COS-7 cells show that the 3'-UTR sequence has a very strong inhibitory effect on t-PA translation. The deletion of 3'-UTR results in 3-8-fold increase of t-PA expression. Further study shows that an AU-rich sequence of some 200 nt at 3' end of 3'-UTR is responsible for the translational inhibition. RNA stability experiment reveals that the AU-rich segment leads to a 3-fold decrease of t-PA mRNA stability. The insertion of this segment into the 3'-UTR of luciferase gene results in an obvious inhibition of Luc expression. A model is proposed for the regulation of t-PA expression.
    Science in China. Series B, Chemistry, life sciences & earth sciences 11/1995; 38(10):1253-60.
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    ABSTRACT: Genes encoding single-chain antibodies have been first constructed, which consist of the heavy and light chain variable domains of antibody PS-9 joined together by a flexible peptide linker. The genes were cloned into coat protein g3p genes of pCANTAB5 phagemids, and expressed as fusion proteins on the phage tips. Immunological assay demonstrated that the engineered antibodies specifically bound to cancer cells LS-174-T as well as to pure bovine submaxillary gland mucin. Their specificity and affinity appeared the same as their parent antibodies. Our results supposed that the single-chain antibodies will be a target for the diagnosis and treatment of cancer.
    Science in China. Series B, Chemistry, life sciences & earth sciences 11/1995; 38(10):1230-6.
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    ABSTRACT: Human interferon-gamma (IFN-gamma) cDNA was synthesized, and it makes the usage of favorable codons in E. coli. The authors got 9 different expression plasmids which contain the synthetic IFN-gamma-cDNA and have different spaces between SD sequence and ATG. The free energies G0f298 in the formation of stable secondary structure in the translation initiation region (TIR) are different in various expression plasmids. One of them, pLY4-gamma 5, can highly yield INF-gamma which will be about 60%-80% of the total bacterial proteins, such a high expression was hardly noted in literature. The reasons of high expression in this work are optimal spaces between SD and ATC, favorable delta G0f298, favourable condons usage for E. coli.
    Science in China. Series B, Chemistry, life sciences & earth sciences 10/1995; 38(9):1084-93.
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    ABSTRACT: X-band electron spin resonance spectroscopy was used to investigate the binding of Mn2+ to the apo-forms of calcineurin and its A and B subunits. The results indicated the presence of 2 Mn2+ binding sites of different affinities (20 mumol/L and 60 mumol/L) in the calcineurin A subunit and 4 Mn2+ binding sites in the calcineurin subunit B, 2 high affinity and 2 low affinity binding sites with Kd's of 4 mumol/L and 90 mumol/L, respectively. Interestingly and quite surprisingly, Mn2+ binding to the holoenzyme was characterized by only 2 binding sites with Kd's of 7 mumol/L and 33 mumol/L. However, in the presence of calmodulin about 10 Mn2+ sites were detected, and the Mn2+ calmodulin-calcineurin complex exhibited enzymatic activity. These results, based on direct spectral measurements of the metal ligand, demostrate that Mn2+ binds to both free subunits of calcineurin in a manner distinct from binding to the holoenzyme. Also, the data suggest that conformational changes occur upon heterodimer formation and association of the holoenzyme with the regulatory protein calmodulin.
    Science in China. Series B, Chemistry, life sciences & earth sciences 10/1995; 38(9):1117-22.
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    ABSTRACT: The determination of deshexapeptide (B25-B30) insulin (DHI) was divided into two steps. At the first step, the rough structure model of DHI molecule was determined by using the molecular replacement method associated with the molecular close-packing method at 0.30 nm resolution based on the reflection data collected on four-cycle diffractometer. At the second step, the DHI model was adjusted and refined at 0.25 nm resolution based on the data collected on Area Detector. 40 water molecules were determined during the refinement, the final R-factor is 0.185 with R.M.S. deviation of 0.002 nm for bond lengths and 1.9 degrees for bond angles. The differences in conformation and function of DHI with other insulin analogues were compared and discussed.
    Science in China. Series B, Chemistry, life sciences & earth sciences 10/1995; 38(9):1094-100.
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    ABSTRACT: Nucleus may reassemble spontaneously in cell-free mixture of HeLa metaphase chromosomes, Xenopus egg extracts and ATP-regenerating system, and the nucleus shows some biological activities. It is found that, after being injected into unfertilized mature eggs, the cell-free reassembled nuclei can cause the eggs to cleave and reconstitute asters in their cytoplasm, and the injected nuclei undergo changes in response to cell cycle regulators stored in the eggs, and that reinjecting cytostatic factors (CSF) into the eggs can stabilize the eggs in mitotic phase, cause the nuclei disassembly and chromatin condensation to chromosomes.
    Science in China. Series B, Chemistry, life sciences & earth sciences 10/1995; 38(9):1075-83.
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    ABSTRACT: A theoretical model of multiobjective optimization neural network (MONN) and a new learning algorithm are presented. Experiment results show their effectiveness and advantage.
    Science in China. Series B, Chemistry, life sciences & earth sciences 09/1995; 38(8):971-8.
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    ABSTRACT: FPLC, SDS-PAGE and Western blot techniques are used to analyse the heterogeneity of interferon alpha A (IFN-alpha A) expressed in yeast. The heterogeneity consists of (i) the presence of IFN polymer, (ii) partial processing of signal leader peptide and (iii) internal degradation. The reasons for heterogeneity of gene products in expression system of yeast are analysed. The methods of avoiding heterogeneity, such as depolymerization, adding inhibitors of protease to the culture supernatant, the oligonucleotide-directed deletion mutagenesis and improvements of fermentation, are discussed.
    Science in China. Series B, Chemistry, life sciences & earth sciences 09/1995; 38(8):954-62.