Polynucleotide phosphorylase protects Escherichia coli against oxidative stress.

Escherichia coli polynucleotide phosphorylase (PNPase) primarily functions in RNA degradation. It is an exoribonuclease and integral component of the multienzyme RNA degradosome complex [Carpousis et al. (1994) Cell 76, 889].

Relativistic effects and the unique low-symmetry structures of gold nanoclusters.

The atomic structures of bare gold clusters provide the foundation to understand the enhanced catalytic properties of supported gold nanoparticles. However, the richness of diverse structures and the strong relativistic effects have posed considerable challenges for a systematic understanding of gold clusters with more than 20 atoms. We use photoelectron spectroscopy of size-selected anions, in combination with first principles calculations, to elucidate the structures of gold nanoclusters in a critical size regime from 55 to 64 atoms (1.

[A Pichia pastoris with alpha-1, 6-mannosyltransferases deletion and its use in expression of HSA/GM-CSF chimera].

Yeast is a widely used host for recombinant protein expression. However, glycoproteins derived from yeast contain N-glycan of high mannose type and are usually hyperglycosylated. alpha-1,6-mannosyltransferases gene (och1) encodes the enzyme that initiates the first step of out-chain elongation of high mannose type N-glycan in yeast, which is different from that in human.

Study on the molecular mechanism of inhibiting HIV-1 integrase by EBR28 peptide via molecular modeling approach.

Human immunodeficiency virus type 1 (HIV-1) integrase (IN) is an essential enzyme in the HIV-1 lifecycle which aids the integration of viral DNA into the host chromosome. Recently synthesized 12-mer peptide EBR28, which can strongly bind to IN, is one of the most potential small peptide leading compounds inhibiting IN binding with viral DNA. However, the binding mode between EBR28 peptide with HIV-1 IN and the inhibition mechanism remain uncertain.

Exoribonuclease R in Mycoplasma genitalium can carry out both RNA processing and degradative functions and is sensitive to RNA ribose methylation.

Mycoplasma genitalium, a small bacterium having minimal genome size, has only one identified exoribonuclease, RNase R (MgR). We have purified MgR to homogeneity, and compared its RNA degradative properties to those of its Escherichia coli homologs RNase R (EcR) and RNase II (EcII). MgR is active on a number of substrates including oligoribonucleotides, poly(A), rRNA, and precursors to tRNA.

A filter enhanced sampling and combinatorial scoring study for protein docking in CAPRI.

Protein-protein docking is usually exploited with a two-step strategy, i.e., conformational sampling and decoy scoring.

[Expression and characterization of human sTNFR II-IgG Fc fusion protein in Pichia pastoris].

Aim: To find if human soluble tumor necrosis factor receptor II (p75) fused IgG Fc protein (sTNFR II-IgG Fc) could be expressed in Pichia pastoris with an active dimmer form and characterize its N-linked oligosaccharides.

Methods: Two gene fragment, human sTNFR II and IgGFc, were got by RT-PCR from leucocytes stimulated with LPS. And the chimeric gene sTNFR II-IgG Fc achieved through gene splicing by over lap extension (SOE) method was cloned into pPIC9 and transformed into methanotropic yeast Pichia pastoris.

[Clinical analysis of PLI, GI and SBI in patients with fixed orthodontic appliances].

Purpose: The aim of the present study was to carry out a detailed analysis of the data on PLI, GI, SBI in fixed orthodontic patients.

Methods: 375 middle school students aged 12 to 15 years old were selected as control group, including 196 boys and 179 girls. 331 patients with fixed orthodontic appliances aged 12 -15 years from city were used as experimental group, including 101 boys and 230 girls without mouth-breathing.

Quantification of RNA damage by reverse transcription polymerase chain reactions.

RNA damages, such as those generated by nucleic acid-modifying agents, occur randomly in RNA and present challenging problems to organisms. It has been unclear how RNA function would be affected by many forms of RNA damage and how cells are protected against the damage. Elucidation of these mechanisms has been hampered by the lack of sensitive and efficient methodologies detecting damages randomly occurring in RNA, especially for the damage of a specific RNA.

Inversion formula of multifractal energy dissipation in three-dimensional fully developed turbulence.

The concept of inverse statistics in turbulence has attracted much attention in recent years. It is argued that the scaling exponents of the direct structure functions and the inverse structure functions satisfy an inversion formula. This proposition has already been verified by numerical data using the shell model.

[Expression in Pichia pastoris and properties of human serum albumin-interferon alpha2b chimera].

To reduce the serum clearance of interferon alpha2b, a chimeric gene encoding an human serum albumin(HSA)--human interferon alpha2b(IFNalpha2b) fusion protein was overexpressed in Pichia pastoris. After fermentation in a 5L bioreactor, the fusion protein, capable of cross-reacting with anti-IFN alpha and anti-HSA antibody, was purified from the culture of the recombinant yeast by ultrafiltration, blue Sepharose affinity, phenyl hydrophobic interaction and Q ion exchange chromatography. Its IFNa2b moiety exhibits antiviral activity similar to that of recombinant human IFNa2b.

[Treatment of Angle Class II division I malocclusion cases with Twin-block appliance combined with face bow and intermaxillary elastic: report of 17 cases].

Purpose: The aim of this study was to evaluate the clinical value of the Twin-block appliance combined with face bow and intermaxillary elastic on Class II division I malocclusion in 17 cases.

Methods: 17 cases with skeletal Class II(I) malocclusion were included, all cases were treated with Twin-block appliance combined with face bow and intermaxillary elastic. The methods of bite construction, fabrication of the application were introduced.

Biologically enhanced sampling geometric docking and backbone flexibility treatment with multiconformational superposition.

An efficient biologically enhanced sampling geometric docking method is presented based on the FTDock algorithm to predict the protein-protein binding modes. The active site data from different sources, such as biochemical and biophysical experiments or theoretical analyses of sequence data, can be incorporated in the rotation-translation scan. When discretizing a protein onto a 3-dimensional (3D) grid, a zero value is given to grid points outside a sphere centered on the geometric center of specified residues.

[Study of recombinant stem cell factor].

Stem cell factor is an important hematopoietic growth factor. In this study, the human stem cell factor was produced by recombinant E. coli, and the structure and biological activity of the recombinant stem cell factor(rhSCF) was studied.

Co-evolution of tRNA 3' trailer sequences with 3' processing enzymes in bacteria.

Maturation of the tRNA 3' terminus is a complicated process in bacteria. Usually, it is initiated by an endonucleolytic cleavage carried out by RNase E and Z in different bacteria. In Escherichia coli, RNase E cleaves AU-rich sequences downstream of tRNA, producing processing intermediates with a few extra residues at the 3' end; these are then removed by exoribonuclease trimming to generate the mature 3' end.

The functional basis of mycophenolic acid resistance in Candida albicans IMP dehydrogenase.

Candida albicans is an important fungal pathogen of immunocompromised patients. In cell culture, C. albicans is sensitive to mycophenolic acid (MPA) and mizoribine, both natural product inhibitors of IMP dehydrogenase (IMPDH).

[Cloning of hIL-1Ra gene and its expression in E.coli].

Aim: To clone human IL-1Ra gene and express it in E.coli.

Methods: Human IL-1Ra cDNA was obtained by RT-PCR with the the total RNA extracted from human peripheral blood leucocytes as template.

[Study on genomic diversity among different isolates of Schistosoma japonicum in China].

Objective: To study genomic diversity among the isolates of Schistosoma japonicum in China.

Methods: Schistosome adults were collected from different endemic areas. Mitochondrial NADH dehydrogenase 1 (ND1) and cytochrome C oxidase 1 (CO1) gene fragments of the worms were amplified by PCR, cloned into plasmid, and finally sequenced.

[Cloning of IL-1 beta gene and expression in E. coli].

IL-1 beta cDNA was obtained by RT-PCR with the template of the total RNA extracted from leukocytes which was separated from human peripheral blood. 5' and 3' primers were synthesized according to literaturees reported sequence of IL-1 beta. IL-1 beta gene was highly expressed in E.

Vitamin C prevents hyperbaric oxygen-induced growth retardation and lipid peroxidation and attenuates the oxidation-induced up-regulation of glutathione in guinea pigs.

Hyperbaric oxygen therapy is used to treat various clinical conditions, but it also causes oxidative damage. The objectives of this study are to determine if increased vitamin C intake can prevent hyperbaric oxygen-induced damage and to determine interactions among vitamin C, glutathione and vitamin E in response to oxidative stress. The growth rates of unexposed guinea pigs fed 1.