Improvement of hEGF Production with Enhanced Cell Division Ability Using Dissolved Oxygen Responses to Pulse Addition of Tryptone

Zhi-Yong Zheng,Xiaobei Zhan,Chi Chung Lin,Shan-Jing Yao 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.1

Tryptone has multiple and complex effects on cell physiology and process performance in pulse fed-batch cultivation of recombinant Escherichia coli. By applying feedback control of dissolved oxygen signal responding to pulse in the feed rate, the production of acetate was avoided and the optimization of production of recombinant human epidermal growth factor (hEGF) was successfully achieved. With the addition of an optimum amount of tryptone along with glucose in the pulse fed-batch cultivation of E. coli, the ability of the cell to divide and the stability of the plasmid within the bacteria were improved. Consequently, segregation of the cells into a viable but non-culturable physiological state was alleviated. Addition of tryptone also enhanced cell respiration before and after hEGF expression and thus further benefited the production of recombinant hEGF. Excessive addition of tryptone resulted in low sensitivity of the oscillation of dissolved oxygen signal and poor operability of pulse fed-batch cultivation as this led to an accumulation of acetate, which weakened the dissolved oxygen signal responses. Consequently, the production of recombinant protein was considerably reduced. By combining the process performance and the positive effect of complex media pulse addition on bacterial metabolism, the optimal production conditions of hEGF were successfully determined. A high cell density of 91 g/L dry cell weight was obtained under these optimal production conditions. Furthermore, a high level of 0.24 g/L hEGF was attained leading to a 32.6% increase in product yield as compared to the controls.

Effect of Metabolic Structures and Energy Requirements on Curdlan Production by Alcaligenes faecalis

Zheng, Zhi-Yong,Lee, Jin-Woo,Zhan, Xiao Bei,Shi, Zhongping,Wang, Lei,Zhu, Li,Wu, Jian-Rong,Lin, Chi Chung Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.4

A comprehensive metabolic network was proposed for Alcaligenes faecalis and employed in a stoichiometrically based flux balance model for curdlan production optimization. The maximal yield of curdlan was evaluated for curdlan batch production. Various metabolic structures and metabolic pathway distributions related with the curdlan maximal yield was evaluated. The results showed that the energy efficiency rather than the substrate supply was the major constraint for the enhancement of curdlan production. The increase in specific rate of glucose uptake could enhance curdlan production yield due to the decrease of the ratio of metabolic maintenance to substrate consumption. However, some of the energy loss and nutrient limitation associated with the increase of metabolic maintenance would adversely affect the conversion efficiency of the substrate.

Radiation Hybrid Mapping and mRNA Expression of Chicken N- myc downregulated gene 4

Yong Tian,Li Zhi Lu,Yan Fu,Ai Ping Yuan,Guo Qin Li,Qing Yan Yuan,Zheng Rong Tao,Jin Zhao 한국유전학회 2007 Genes & Genomics Vol.29 No.4

N-myc downregulated gene 4 (NDRG4) is a member of the N-myc downregulated gene family which belongs to the alpha/beta hydrolase superfamily. The protein encoded by this gene is a cytoplasmic protein that may be involved in the regulation of mitogenic signalling in vascular smooth muscle cells. To map NDRG4 gene in chicken chromosome, a 6,000 rads chicken- hamster radiation hybrid panel was used. Primers were designed according to the published human sequence for amplification of chicken NDRG4. We compared the corresponding human mRNA sequence with the predicted coding sequence of chicken NDRG4, and found that the assembled contig shared a high percentage of similarity with that of human gene. PCR of samples from ChickRH6 revealed the locations of NDRG4 to be linked to the maker PARD6G (5 cR away) with a LOD score 20.46. In addition, we detected the mRNA expression and distribution of chicken NDRG4 in various tissues by RT-PCR, and found that NDRG4 was highly expressed in chicken brain and heart, whereas lowly but detectable in thymus. The mRNA expression of this gene in chicken liver, spleen, lung and muscle was rarely detectable under present experimental conditions.

Closed-form solution of axisymmetric deformation of prestressed Föppl-Hencky membrane under constrained deflecting

Yong-Sheng Lian,Jun-Yi Sun,Jiao Dong,Zhou-Lian Zheng,Zhi-Xin Yang 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.69 No.6

In this study, the problem of axisymmetric deformation of prestressed Föppl-Hencky membrane under constrained deflecting was analytically solved and its closed-form solution was presented. The small-rotation-angle assumption usually adopted in membrane problems was given up, and the initial stress in membrane was taken into account. Consequently, this closed-form solution has higher calculation accuracy and can be applied for a wider range in comparison with the existing approximate solution. The presented numerical examples demonstrate the validity of the closed-form solution, and show the errors of the contact radius, profile and radial stress of membrane in the existing approximate solution brought by the small-rotation-angle assumption. Moreover, the influence of the initial stress on the contact radius is also discussed based on the numerical examples.

Investigation on damage assessment of fiber-reinforced prestressed concrete containment under temperature and subsequent internal pressure

Zhi Zheng,Yong Wang,Shuai Huang,Xiaolan Pan,Chunyang Su,Ye Sun Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

Following a loss of coolant accident (LOCA), prestressing concrete containment vessels (PCCVs) may experience high thermal load as well as internal pressure. The high temperature stress would increase the risk of premature damage to the containment, which reduces the safety margin during the increasing internal pressure. However, current investigations cannot clearly address the issues of thermal-pressure coupling effect on damage propagation and thus safety of the containment. Thus, this paper offers three simple and powerful damage parameters to differentiate the severity of damage of the containment. Moreover, despite of the temperature action severely threatening the pressure performance of the containment, the research regarding the improvement of the resistant performance of the containment is quite scarce. Therefore, in this paper, a comprehensive comparison of damage propagation and mechanism between conventional and fiber-reinforced concrete (FRC) containments is performed. The effects of fiber characteristics parameters on damage propagation of structures following the LOCA are also specifically revealed. It is found that the proposed damage indices can properly indicate state of damage in the containment body and the addition of fiber can be used to obviously mitigate the damage propagation in PCCV considering the thermal-pressure coupling.

Proteomic analyses for profiling regulated proteins/enzymes by <i>Fucus vesiculosus</i> fucoidan in B16 melanoma cells: A combination of enzyme kinetics functional study

Wang, Zhi-Jiang,Zheng, Li,Yang, Jun-Mo,Kang, Yani,Park, Yong-Doo Elsevier 2018 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES Vol.112 No.-

<P><B>Abstract</B></P> <P>Fucoidans are complex sulfated polysaccharides that have a wide range of biological activities. Previously, we reported the various effects of <I>Fucus vesiculosus</I> fucoidan on tyrosinase and B16 melanoma cells. In this study, to identify fucoidan-targeted proteins in B16 melanoma cells, we performed a proteomics study and integrated enzyme kinetics. We detected 19 candidate proteins dysregulated by fucoidan treatment. Among the probed proteins, the enzyme kinetics of two candidate enzymes, namely lactate dehydrogenase (LDH) as an upregulated protein and superoxide dismutase (SOD) as a downregulated enzyme, were determined. The enzyme kinetics results showed that <I>Fucus vesiculosus</I> fucoidan significantly inhibited LDH catalytic function while it did not affect SOD activity even at a high dose, while only slightly decreased activity (up to 10%) at a low dose. Based on our previous and present observations, fucoidan could inhibit B16 melanoma cells growth via regulating proteins/enzymes expression levels such as LDH and SOD known as cell survival biomarkers. Interestingly, both expression level and enzyme catalytic activity of LDH were regulated by fucoidan, which could directly induce the apoptotic effect on B16 melanoma cells along with SOD downregulation. This study highlights how combining proteomics with enzyme kinetics can yield valuable insights into fucoidan targets.</P>

SCYL1BP1 has Tumor-suppressive Functions in Human Lung Squamous Carcinoma Cells by Regulating Degradation of MDM2

Yang, Zhi-Ping,Xie, Yong-Hong,Ling, Dan-Yan,Li, Jin-Rui,Jiang, Jin,Fan, Yao-Hua,Zheng, Jia-Lian,Wu, Wan-Xin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

SCY1-like 1-binding protein 1 (SCYL1BP1) is a newly identified transcriptional activator domain containing protein with many unknown biological functions. Recently emerging evidence has revealed that it is a novel regulator of the p53 pathway, which is very important for the development of human cancer. However, the effects of SCYL1BP1 on human lung squamous carcinoma cell biological behavior remain poorly understood. In this study, we present evidence that SCYL1BP1 can promote the degradation of MDM2 protein and further inhibit the G1/S transition of lung squamous carcinoma cell lines. Functional assays found that reintroduction of SCYL1BP1 into lung squamous carcinoma cell lines significantly inhibited cell proliferation, migration, invasion and tumor formation in nude mice, suggesting strong tumor suppressive function of SCYL1BP1 in lung squamous carcinoma. Taken together, our data suggest that the interaction of SCYL1BP1/MDM2 could accelerate MDM2 degradation, and may function as an important tumor suppressor in lung squamous carcinomas.

Vasodilation Effect of 2-benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin- 1-one

Wei-Qi,Yong-Xiao Cao,Zhi-Zheng Xiong,Ting-Ting Chen,Xiao-Yan Gao,Hang Yu,San-Qi Zhang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.8

A 2-Benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin-1-one (ZC2) is a newly synthesized isoquinolinone compound. Its effect on vasodilation was evaluated in the present study. Isometric tension of rat artery rings was recorded by a sensitive myography system in vitro. The results showed that ZC2 relaxed rat mesenteric arteries pre-contracted by KCl, phenylephrine and 9, 11- dideoxy- 11α, 9α-epoxymethano-prostaglandin F2α (U46619), and abdominal aorta pre-contracted by KCl in a concentration-dependent manner. The ZC2-induced vasodilation was not affected by an endothelium denudation. ZC2 rightwards shifted the concentration-contraction curves, induced by KCl, phenylephrine, and 5-hydroxytryptamine (5-HT) in a non-parallel manner, which suggests that the vasodilation effects are most likely via voltage-dependent calcium channel (VDCC) and receptor-operated calcium channel (ROCC). Moreover, in Ca2+-free medium, ZC2 concentration-dependently depressed the vasoconstrictions induced by phenylephrine and CaCl2, and decreased a contractile response induced by caffeine, which indicates a role of extracellular Ca2+ influx inhibition through VDCC and ROCC, and intracellular Ca2+ release from Ca2+ store via the ryanodine receptors. Glibenclamide did not affect the vasodilation induced by ZC2, suggesting that ATP sensitive potassium channel is not involved in the vasodilation. The results indicate that ZC2 induces vasodilation by inhibiting the VDCC and ROCC, and receptormediated Ca2+ influx and release. The inhibition of intracellular Ca2+ release may be mediated via the ryanodine receptors.

Separation of arenols from a low-temperature coal tar by liquid-liquid extraction

Hua-Shuai Gao,Zhi-Min Zong,Zheng Yang,Dao-Guang Teng,Xiu-Hua Sun,Li Yan,Xian-Yong Wei,Qing-Jie Guo,Tian-Sheng Zhao,Hong-Cun Bai 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.5

Low-temperature coal tar (LTCT) is a sticky liquid mixture produced mainly from coal pyrolysis, which contains various value-added chemicals (VACs). Liquid-liquid extraction is considered as one of the green and effective ways to explore the organic composition and separate the VACs from LTCT. Herein, petroleum ether, methanol, and carbon disulfide were used to extract arenols from a LTCT. As a result, the relative content and absolute content of arenols extracted from the LTCT are ca. 96.3% and 85.9%, respectively. Among them, p-cresol is predominant, accounting for 22.2%. The isolated contents of arenols are up to 84.6%. Moreover, a kilogram-scale operation was carried out under the same conditions, which offers a potential application in industrial production.

Deuterium Clusters Fusion Induced by the Intense Femtosecond Laser Pulse

Hong-Jie, Liu,Zhi-Jian, Zheng,Yu-Qiu, Gu,Bao-Han, Zhang,Yong-Joo, Rhee,Sung-Mo, Nam,Jae-Min, Han,Yong-Woo, Rhee,Kwon-Hae, Yea,Jia-Bin, Chen,Hong-Bin, Wang,Chun-Ye, Jiao,Ying-Ling, He,Tian-Shu, Wen,Xia ALLERTON PRESS INC 2007 CHINESE PHYSICS LETTERS Vol.24 No.2

<P>Neutrons (2.45 MeV) from deuterium cluster fusion induced by the intense femtosecond (30 fs) laser pulse are experimentally demonstrated. The average neutron yield 10<SUP>3</SUP> per shot is obtained. It is found that the yield slightly increases with the increasing laser spot size. No neutron can be observed when the laser intensity I < 4.3×10<SUP>15</SUP> W/cm<SUP>2</SUP>.</P>