Production and Optimization of a Kiwi Pectin Methylesterase Inhibitor in Pichia pastoris GS115

Qian Liu,Wentao Xu,Shiwen Han,Dongyan Cao,Xiaoyun He,Kunlun Huang,Xiaohong Mei 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.6

Gene sequence coding of a kiwi pectin methylesteraseinhibitor was optimized, synthesized, and expressedin Pichia pastoris GS115 based on P. pastoris preferredcodon usage. The expression level of the recombinantprotein (kwPMEI) increased by 89.74% after codonoptimization. Expression conditions of recombinant strainswere optimized. The highest production of kwPMEI wasachieved using 0.8% sorbitol (added every 24 h), 0.05%oleic acid (added at the beginning of induction), and 0.5%methanol (added every 12 h). kwPMEI was purified usingNi2+ chelating affinity chromatography and 17 mg of theprotein was harvested from 60 mL of a culture supernatant. Activity analysis showed that kwPMEI efficiently inhibitedthe activity of different plant PMEs. High expression levelsand purification of kwPMEI will promote applications infruit and vegetable juices.

Phage transcription activator RinA regulates Staphylococcus aureus virulence by governing sarA expression

Jiang Ming,Li Yilin,Sun Baolin,Xu Shiwen,Pan Ting,Li Yujie 한국유전학회 2023 Genes & Genomics Vol.45 No.2

Background Staphylococcus aureus is a major human pathogen, that can lead to various community- and hospital-acquired infections. RinA is a transcription activator of S. aureus phage φ 11 involved in phage packaging and virulence gene transfer. However, little is known about the molecular mechanism of RinA in the regulation of virulence. Objective We aimed to explore a novel contribution of RinA in the regulation of virulence and provide a new drug target in the treatment of S. aureus infections. Methods The specific functions of RinA in S. aureus were analyzed by the methods of growth curve, real-time quantitative PCR (RT-qPCR), subcellular localization, electrophoretic mobility shift assay (EMSA), infection model of Galleria mellonella larvae and the mouse subcutaneous abscess model. Results In this study, we demonstrated that RinA is a protein evenly distributed in the cytoplasm of S. aureus, and its deletion could cause the growth defects. RT-qPCR and EMSA determined that rinA could negatively regulate the expression of sarA by directly binding to its promoter, and vice versa. The Galleria mellonella larvae infection and mouse subcutaneous abscess models revealed that the rinA mutant strain exhibited obvious virulence defects. When sarA is knocked out, the virulence of S.aureus had no significantly changes whether rinA is knocked out or not. Conclusion Our fndings demonstrated that phage transcription activator RinA regulates S. aureus virulence by governing sarA expression.

Heteroatoms in situ-doped hierarchical porous hollow-activated carbons for high-performance supercapacitor

Yan Rui,Wang Kai,Tian Xiaodong,Li Xiao,Yang Tao,Xu Xiaotong,He Yiting,Lei Shiwen,Song Yan 한국탄소학회 2020 Carbon Letters Vol.30 No.3

Heteroatoms in situ-doped hierarchical porous hollow-activated carbons (HPHACs) have been prepared innovatively by pyrolyzation of setaria viridis combined with alkaline activation for the frst time. The micro-morphology, pore structure, chemical compositions, and electrochemical properties are researched in detail. The obtained HPHACs are served as outstand�ing electrode materials in electrochemical energy storage ascribe to the particular hierarchical porous and hollow structure, and the precursor setaria viridis is advantage of eco-friendly as well as cost-efective. Electrochemical measurement results of the HPHACs electrodes exhibit not only high specifc capacitance of 350 F g−1 at 0.2 A g−1, and impressive surface specifc capacitance (Cs) of 49.9 μF cm−2, but also substantial rate capability of 68% retention (238 F g−1 at 10 A g−1) and good cycle stability with 99% retention over 5000 cycles at 5 A g−1 in 6 M KOH. Besides, the symmetrical supercapacitor device based on the HPHACs electrodes exhibits excellent energy density of 49.5 Wh kg−1 at power density of 175 W kg−1 , but still maintains favorable energy density of 32.0 Wh kg−1 at current density of 1 A g−1 in 1-ethy-3-methylimidazolium tetrafuoroborate (EMIMBF4) ionic liquid electrolyte, and the excellent cycle stability behaviour shows the nearly 97% ratio capacitance retention of the initial capacitance after 10,000 cycles at current density of 2 A g−1. Overall, the results indicate that HPHACs derived from setaria viridis have appealing electrochemical performances thus are promising electrode materi�als for supercapacitor devices and large-scale applications.

Effect of phosphorus deficiency on erythrocytic morphology and function in cows

Ziwei Zhang,Mingyu Bi,Jie Yang,Haidong Yao,Zhonghua Liu,Shiwen Xu 대한수의학회 2017 Journal of Veterinary Science Vol.18 No.3

The aim of this study was to evaluate the influence of phosphorus (P) deficiency on the morphological and functional characteristics of erythrocytes in cows. Forty Holstein-Friesian dairy cows in mid-lactation were randomly divided into two groups of 20 each and were fed either a low-P diet (0.03% P/kg dry matter [DM]) or a control diet (0.36% P/kg DM). Red blood cell (RBC) indices results showed RBC and mean corpuscular hemoglobin decreased while mean corpuscular volume increased significantly (p < 0.05) in P-deficient cows. Erythrocyte morphology showed erythrocyte destruction in P-deficient cows. Erythrocytes’ functional characteristics results showed total bilirubin and indirect bilirubin concentrations and aspartate transaminase and alanine transaminase activity levels in the serum of P-deficient cows were significantly higher than those in control diet-fed cows. Activities of superoxide dismutase and glutathione peroxidase in erythrocytes were lower, while the malondialdehyde content was greater, in P-deficient cows than in control diet-fed cows. Na+/K+-ATPase and Mg2+-ATPase activities were lower in P-deficient cows than in control diet-fed cows; however, Ca2+-ATPase activity was not significantly different. The phospholipid composition of the erythrocyte membrane changed and membrane fluidity rigidified in P-deficient cows. The results indicate that P deficiency might impair erythrocyte integrity and functional characteristics in cows.

Stress-induced expression of the sweetpotato gene <i>IbLEA14</i> in poplar confers enhanced tolerance to multiple abiotic stresses

Ke, Qingbo,Park, Sung-Chul,Ji, Chang Yoon,Kim, Ho Soo,Wang, Zhi,Wang, Shiwen,Li, Hongbing,Xu, Bingcheng,Deng, Xiping,Kwak, Sang-Soo Elsevier 2018 Environmental and experimental botany Vol.156 No.-

<P><B>Abstract</B></P> <P>Late embryogenesis abundant (LEA) proteins are small, highly hydrophilic proteins that act as protectors of macromolecules and increase abiotic stress tolerance in plants. We previously reported that overexpressing sweetpotato <I>IbLEA14</I> under the control of the <I>CaMV 35S</I> promoter increased osmotic and salt stress tolerance in transgenic sweetpotato calli. In this study, we generated transgenic poplar plants (<I>Populus alba × P. glandulosa</I>) expressing <I>IbLEA14</I> under the control of the oxidative stress-inducible <I>SWPA2</I> promoter (referred to as SL plants). Among the 15 SL plants obtained, three lines (SL2, SL7, and SL12) were established based on <I>IbLEA14</I> transcript levels, tolerance to salt stress and Southern blot analysis. The SL plants exhibited less damage in response to methyl viologen-mediated oxidative stress than non-transgenic (NT) plants. SL plants also showed enhanced tolerance to drought, salt, and heat stress, which was associated with higher photosystem II efficiency and lower malondialdehyde levels compared with NT plants. Furthermore, SL plants had higher levels of monolignol biosynthesis-related gene transcripts under drought stress compared with NT plants. Finally, SL plants exhibited increased tolerance to heat stress, which is associated with the high thermostability of IbLEA14 protein. SL plants might be useful for reforestation on global marginal lands, including desertification and reclaimed areas.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>IbLEA14</I> gene was transformed into poplar plants. </LI> <LI> Transgenic poplars exhibit increased tolerance to MV-mediated oxidative, drought, salt and heat stress. </LI> <LI> Overproduction of IbLEA14 affects lignification and thermostability of transgenic poplars. </LI> </UL> </P>