Molecular and Biochemical Characterization of a Novel Intracellular Low-Temperature-Active Xylanase

( Jun Pei Zhou,),( Yan Yan Dong ),( Xiang Hua Tang ),( Jun Jun Li ),( Bo Xu ),( Qian Wu ),( Ya Jie Gao ),( Lu Pan ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.4

A 990 bp full-length gene (xynAHJ2) encoding a 329- residue polypeptide (XynAHJ2) with a calculated mass of 38.4 kDa was cloned from Bacillus sp. HJ2 harbored in a saline soil. XynAHJ2 showed no signal peptide, distinct amino acid stretches of glycoside hydrolase (GH) family 10 intracellular endoxylanases, and the highest amino acid sequence identity of 65.3% with the identified GH 10 intracellular mesophilic endoxylanase iM-KRICT PX1-Ps from Paenibacillus sp. HPL-001 (ACJ06666). The recombinant enzyme (rXynAHJ2) was expressed in Escherichia coli and displayed the typical characteristics of low-temperatureactive enzyme (exhibiting optimum activity at 35 o C, 62% at 20 o C, and 38% at 10 o C; thermolability at ≥45 o C). Compared with the reported GH 10 low-temperature-active endoxylanases, which are all extracellular, rXynAHJ2 showed low amino acid sequence identities (<45%), low homology (different phylogenetic cluster), and difference of structure (decreased amount of total accessible surface area and exposed nonpolar accessible surface area). Compared with the reported GH 10 intracellular endoxylanases, which are all mesophilic and thermophilic, rXynAHJ2 has decreased numbers of arginine residues and salt bridges, and showed resistance to Ni 2+ , Ca 2+ , or EDTA at 10 mM final concentration. The above mechanism of structural adaptation for low-temperature activity of intracellular endoxylanase rXynAHJ2 is different from that of GH 10 extracellular low-temperature-active endoxylanases. This is the first report of the molecular and biochemical characterizations of a novel intracellular low-temperatureactive xylanase.

Production and Characterization of Ethanol- and Protease-Tolerant and Xylooligosaccharides-Producing Endoxylanase from Humicola sp Ly01

( Jun Pei Zhou ),( Qian Wu ),( Rui Zhang ),( Yu Ying Yang ),( Xiang Hua Tang ),( Jun Jun Li ),( Jun Mei Ding ),( Yan Yan Dong ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.6

This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% KH2PO4, and 0.5% peptone; initial pH 7.0; incubation time 72 h; 30℃; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at 60℃ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at 30℃ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 μmol/ml reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.

Cloning, Heterologous Expression, and Characterization of Novel Protease- Resistant α-Galactosidase from New Sphingomonas Strain

( Jun Pei Zhou ),( Yan Yan Dong ),( Jun Jun Li ),( Rui Zhang ),( Xianghua Tang ),( Yuelin Mu ),( Bo Xu ),( Qian Wu ),( Zun Xi Huang ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.11

The α-galactosidase-coding gene agaAJB13 was cloned from Sphingomonas sp. JB13 showing 16S rDNA (1,343 bp) identities of ≤97.2% with other identified Sphingomonas strains. agaAJB13 (2,217 bp; 64.9% GC content) encodes a 738-residue polypeptide (AgaAJB13) with a calculated mass of 82.3 kDa. AgaAJB13 showed the highest identity of 61.4% with the putative glycosyl hydrolase family 36 α-galactosidase from Granulicella mallensis MP5ACTX8 (EFI56085). AgaAJB13 also showed <37% identities with reported protease-resistant or Sphingomonas α-galactosidases. A sequence analysis revealed different catalytic motifs between reported Sphingomonas α-galactosidases (KXD and RXXXD) and AgaAJB13 (KWD and SDXXDXXXR). Recombinant AgaAJB13 (rAgaAJB13) was expressed in Escherichia coli BL21 (DE3). The purified rAgaAJB13 was characterized using p-nitrophenyl-α-D-galactopyranoside as the substrate and showed an apparent optimum at pH 5.0 and 60oC and strong resistance to trypsin and proteinase K digestion. Compared with reported proteaseresistant α-galactosidases showing thermolability at 50oC or 60oC and specific activities of <71 U/mg with or without protease treatments, rAgaAJB13 exhibited a better thermal stability (half-life of >60 min at 60oC) and higher specific activities (225.0-256.5 U/mg). These sequence and enzymatic properties suggest AgaAJB13 is the first identified and characterized Sphingomonas α-galactosidase, and shows novel protease resistance with a potential value for basic research and industrial applications.

Molecular and Biochemical Characterization of a Novel Xylanase from Massilia sp. RBM26 Isolated from the Feces of Rhinopithecus bieti

( Bo Xu ),( Li Ming Dai ),( Jun Jun Li ),( Meng Deng ),( Hua Biao Miao ),( Jun Pei Zhou ),( Yue Lin Mu ),( Qian Wu ),( Xiang Hua Tang ),( Yun Juan Yang ),( Jun Mei Ding ),( Nan Yu Han ),( Zun Xi Huang 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37°C and could maintain at least 96% activity after being placed at 37°C for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, Km, Vmax, and kcat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 μmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

Optimal Tracking Performance of NCSs with Time-delay and Encoding-decoding Constraints

Jun-Wei Hu,Xi-Sheng Zhan,Jie Wu,Huai-Cheng Yan 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.4

In this paper, the tracking performance of networked control systems (NCSs) under energy constraints with time-delay and encoding-decoding is studied. Through spectral factorization and partial decomposition techniques, we can obtain the explicit representation of the optimal performance. It is shown that the optimal performance is affected by non minimum phase (NMP) zeros, unstable poles and other multiple communication constraints such as time-delay, encoding-decoding and additive white Gaussian noise (AWGN). At the same time, the obtained result shows that a two-parameter compensator is superior to a one-parameter compensator. In addition, it is found that time-delay, encoding-decoding and AWGN affected the tracking capability of NCSs. Finally, an example is given for verifying the correctness of the conclusions.

The Influence of Challenge on Cathepsin B and D Expression Patterns in the Silkworm Bombyx mori L.

Wu, Feng-Yao,Zou, Feng-Ming,Jia, Jun-Qiang,Wang, Sheng-Peng,Zhang, Guo-Zheng,Guo, Xi-Jie,Gui, Zhong-Zheng Korean Society of Sericultural Science 2011 International Journal of Industrial Entomology Vol.23 No.1

Cathepsins are well-characterized proteases that are ubiquitously expressed in lysosomes. Previous work revealed that $Bombyx$ $mori$ cathepsins B and D are expressed in the fat body and undergo decomposition during larval-pupal metamorphosis. Quantitative RT-PCR was performed to detect cathepsin gene expression at the transcription level when challenged by $B.$ $mori$ nuclear polyhedrosis virus (BmNPV), temperature and hormones (20-hydroxyecdysone (20E) and juvenile hormone analogue (JHA)). mRNAs encoding cathepsins B and D were significantly enhanced after the larvae were infected with BmNPV, and the peak of the induction appeared at 1 day before spinning. This attenuated the inducing effect on cathepsin expression caused by infection. Temperature shock induced cathepsin expression at the later stage of the $5^{th}$ instar, and transcription levels varied with development stage and temperature. Cathepsin B and D mRNA expression in the fat body were significantly induced by JHA at the day before spinning, and with 20E, the expression reached a peak at the last day of the $5^{th}$ instar. Cathepsin B and D mRNA expression exhibited detectable changes post-treatment, without significant differences between or among the hormone concentrations.

Increased Expression of miR-146a in Children With Allergic Rhinitis After Allergen-Specific Immunotherapy

Xi Luo,Haiyu Hong,Jun Tang,Xingmei Wu,Zhibin Lin,Renqiang Ma,Yunping Fan,Geng Xu,Dabo Liu,Huabin Li 대한천식알레르기학회 2016 Allergy, Asthma & Immunology Research Vol.8 No.2

Purpose: MicroRNAs (miRs) were recently recognized to be important for immune cell differentiation and immune regulation. However, whether miRs were involved in allergen-specific immunotherapy (SIT) remains largely unknown. This study sought to examine changes in miR-146a and T regulatory cells in children with persistent allergic rhinitis (AR) after 3 months of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT). Methods: Twenty-four HDM-sensitized children with persistent AR were enrolled and treated with SCIT (n=13) or SLIT (n=11) for 3 months. Relative miR-146a and Foxp3 mRNA expression, the TRAF6 protein level, and the ratio of post-treatment to baseline IL-10+CD4+ T cells between the SCIT and SLIT groups were examined in the peripheral blood mononuclear cells (PBMCs) of AR patients using quantitative reverse transcription polymerase chain reaction (qRT-PCR), flow cytometry, and Western blot analysis, respectively. Serum levels of IL-5 and IL-10 were determined using ELISA. Results: After 3 months of SIT, both the TNSS and INSS scores were significantly decreased compared to the baseline value (P<0.01). The relative expression of miR-146a and Foxp3 mRNA was significantly increased after both SCIT and SLIT (P<0.01). The ratio of post-treatment to baseline IL-10+CD4+ T cells and the serum IL-10 level were significantly increased in both the SCIT and SLIT groups (P<0.01), whereas the TRAF6 protein level and serum IL-5 level were significantly decreased (P<0.01). No significant differences in these biomarkers were observed between the SCIT and SLIT groups. Conclusions: Our findings suggest that miR-146a and its related biomarkers may be comparably modulated after both SCIT and SLIT, highlighting miR-146a as a potential therapeutic target for the improved management of AR.

The Therapeutic Effects of Tectorigenin on Chemically Induced Liver Fibrosis in Rats and an Associated Metabonomic Investigation

Xing-Xi Gao,Jun-Hua Wu,Da-Hua Shi,Yun-Xi Chen,Jiang-Tao Cui,Yu-Rong Wang,Chun-Ping Jiang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.8

The aim of this study was to investigate the effects of tectorigenin on chemically induced liver fibrosis in rats. Liver fibrosis was induced in rats with carbon tetrachloride, a diet high in fat, cholesterol and alcohol in the drinking water. Our results indicate that tectorigenin treatment significantly inhibited the increases in the activities of alanine aminotransferase (ALT),aspartate aminotransferase (AST) and the increases in the serum levels of hyaluronate (HA), laminin (LN) and procollagen III N-terminal peptide (PIIIP); tectorigenin treatment also significantly inhibited the increases in the amount of collagen in the livers of the fibrogenic rats. Chemically induced liver fibrosis caused a drop in the serum albumin concentration and a decrease in the ratio of albumin to globulin (A/G). Tectorigenin caused a remarkable increase at a dose of 30 mg/kg, but only a slight increase at the lower doses. Tectorigenin was also able to inhibit the increase in the liver lipid peroxidation (LPO), as well as the decrease in the activities of liver superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), caused by liver fibrosis. In addition, we present a related metabolic profile determined, using a 1H NMR spectroscopy and multivariate pattern recognition techniques. The results were consistent with the pathological examination, liver function analysis and liver fibrosis marker analysis. Furthermore, tectorigenin does not cause acute toxicity.

Bifurcations of A Third-Order Common-Base Transistor Circuit

Jian Jun Hou,Jing Tang Wu,Xi Yu Du 대한전자공학회 1992 대한전자공학회 Conference Vol.1992 No.2

Long-circulating siRNA nanoparticles for validating Prohibitin1-targeted non-small cell lung cancer treatment

Zhu, Xi,Xu, Yingjie,Solis, Luisa M.,Tao, Wei,Wang, Liangzhe,Behrens, Carmen,Xu, Xiaoyang,Zhao, Lili,Liu, Danny,Wu, Jun,Zhang, Ning,Wistuba, Ignacio I.,Farokhzad, Omid C.,Zetter, Bruce R.,Shi, Jinjun National Academy of Sciences 2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.112 No.25

<P><B>Significance</B></P><P>This study developed a new generation lipid–polymer hybrid nanoparticle platform for effective systemic delivery of small interfering RNA (siRNA) to tumors, which represents a challenging hurdle for the widespread application of RNA interference (RNAi) in cancer research and therapy. With promising in vivo features such as long blood circulation, high tumor accumulation, and effective gene silencing, the hybrid siRNA nanoparticles were successfully used to reveal and validate a putative therapeutic target, Prohibitin1 (PHB1), in non-small cell lung cancer treatment. In vivo antitumor efficacy results and human tissue microarray analysis further suggested the feasibility of utilizing PHB1 siRNA nanoparticles as a novel therapeutic agent. This hybrid RNAi nanoparticle platform may serve as a valuable tool for validating potential cancer targets and developing new cancer therapies.</P><P>RNA interference (RNAi) represents a promising strategy for identification and validation of putative therapeutic targets and for treatment of a myriad of important human diseases including cancer. However, the effective systemic in vivo delivery of small interfering RNA (siRNA) to tumors remains a formidable challenge. Using a robust self-assembly strategy, we develop a unique nanoparticle (NP) platform composed of a solid polymer/cationic lipid hybrid core and a lipid-poly(ethylene glycol) (lipid-PEG) shell for systemic siRNA delivery. The new generation lipid–polymer hybrid NPs are small and uniform, and can efficiently encapsulate siRNA and control its sustained release. They exhibit long blood circulation (<I>t</I><SUB>1/2</SUB> ∼8 h), high tumor accumulation, effective gene silencing, and negligible in vivo side effects. With this RNAi NP, we delineate and validate the therapeutic role of Prohibitin1 (PHB1), a target protein that has not been systemically evaluated in vivo due to the lack of specific and effective inhibitors, in treating non-small cell lung cancer (NSCLC) as evidenced by the drastic inhibition of tumor growth upon PHB1 silencing. Human tissue microarray analysis also reveals that high PHB1 tumor expression is associated with poorer overall survival in patients with NSCLC, further suggesting PHB1 as a therapeutic target. We expect this long-circulating RNAi NP platform to be of high interest for validating potential cancer targets in vivo and for the development of new cancer therapies.</P>