Catalytic Ability Improvement of Phenylalanine Hydroxylase from Chromobacterium violaceum by N-Terminal Truncation and Proline Introduction

( Zhongmei Liu ),( Zhongyi Cheng ),( Shuangshuang Ye ),( Li Zhou ),( Zhemin Zhou ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.9

Phenylalanine hydroxylase from Chromobacterium violaceum (CvPAH) is a monomeric enzyme that converts phenylalanine to tyrosine. It shares high amino acid identity and similar structure with a subunit of human phenylalanine hydroxylase that is a tetramer, resulting in the latent application in medications. In this study, semirational design was applied to CvPAH to improve the catalytic ability based on molecular dynamics simulation analyses. Four Nterminal truncated variants and one single point variant were constructed and characterized. The D267P variant showed a 2.1-fold increased thermal stability compared to the wild type, but lower specific activity was noted compared with the wild type. The specific activity of all truncated variants was a greater than 25% increase compared to the wild type, and these variants showed similar or slightly decreased thermostability with the exception of the N-Δ9 variant. Notably, the N-Δ9 variant exhibited a 1.2-fold increased specific activity, a 1.3-fold increased thermostability and considerably increased catalytic activity under the neutral environment compared with the wild type. These properties of the N-Δ9 variant could advance medical and pharmaceutical applications of CvPAH. Our findings indicate that the N-terminus might modulate substrate binding, and are directives for further modification and functional research of PAH and other enzymes.

Visualizing the distributions and spatiotemporal changes of metabolites in Panax notoginseng by MALDI mass spectrometry imaging

Chenglong Sun,Shuangshuang Ma,Lili Li,Daijie Wang,Wei Liu,Feng Liu,Lanping Guo,Xiao Wang 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.6

Background: Panax notoginseng is a highly valued medicinal herb used widely in China and many Asiancountries. Its root and rhizome have long been used for the treatment of cardiovascular and hematologicaldiseases. Imaging the spatial distributions and dynamics of metabolites in heterogeneous planttissues is significant for characterizing the metabolic networks of Panax notoginseng, and this will alsoprovide a highly informative approach to understand the complex molecular changes in the processing ofPanax notoginseng. Methods: Here, a high-sensitive MALDI-MS imaging method was developed and adopted to visualize thespatial distributions and spatiotemporal changes of metabolites in different botanical parts of Panaxnotoginseng. Results: A wide spectrum of metabolites including notoginsenosides, ginsenosides, amino acids, dencichine,gluconic acid, and low-molecular-weight organic acids were imaged in Panax notoginseng rhizomeand root tissues for the first time. Moreover, the spatiotemporal alterations of metabolites during thesteaming of Panax notoginseng root were also characterized in this study. And, a series of metabolitessuch as dencichine, arginine and glutamine that changed with the steaming of Panax notoginseng weresuccessfully screened out and imaged. Conclusion: These spatially-resolved metabolite data not only enhance our understanding of the Panaxnotoginseng metabolic networks, but also provide dire

Influence of wheat-walnut intercropping on the Sitobion avenae and its predatory natural enemies

Gao Haifeng,Jia Shuangshuang,Liu Yongqiang,Shen Yuyang,Li Guangkuo,Zhao Sifeng,Ge Feng 한국응용곤충학회 2024 Journal of Asia-Pacific Entomology Vol.27 No.1

Intercropping is widely applied all over the world, and it often causes significant changes in the number of arthropod communities. Walnut-wheat intercropping systems are commonly applied in Southern Xinjiang of China. But it is still not clear how wheat-walnut intercropping influence pest and natural enemy populations, and their ratio in wheat fields. To clarify this question and provide guidance to pest management, field surveys were conducted in Xinjiang during 2017–2019. Three intercropping treatments were tested, which were wheat-walnut 10:6, 25:6, and monoculture wheat. Our results showed that the abundance of predators (mainly ladybeetles and lacewings) increased in wheat under wheat-walnut intercropping systems (especially in intercrop treatment 10:6). Compared with monoculture wheat, the ratio of predators to Sitobion avenae was not enhanced in wheatwalnut intercropping fields. S. avenae populations increased in the walnut intercropped wheat fields. The intercropping system was not beneficial to S. avenae control in wheat fields. Different measures should be taken to strengthen the control of S. avenae in walnut intercropped wheat fields.

再修正琼斯模型构建

薛双,双,(shuangshuang Xue),刘,丽,娜(Lina Liu) 아시아무역학회 2015 Journal of Asia Trade and Business Vol.2 No.1

Under the background of the corporate governance of separation between the ownership and the right of management, earnings management is a common phenomenon in Chinese capital market, however the estimation of earnings management’ degree is the premise of the research on earnings management. This paper summarized the measurement model of accrual earnings management that and considered that through replacement and restructuring of non operation assets, debt restructuring and asset gift can adjust the items below the line, which can affect the accrued profit of enterprise; Inventory impairment provision and reversal can also affect the corporate earnings, and then propose a new measurement model of earnings management. Through empirical analysis we found that each factor of the new model can pass the significant test, this new model can fully reflect the phenomenon of earnings management of enterprises, so a new method for the measurement of enterprises’ earnings management is proposed.

Brain Regional Homogeneity Changes in Cirrhotic Patients with or without Hepatic Encephalopathy Revealed by Multi-Frequency Bands Analysis Based on Resting-State Functional MRI

Gaoyan Zhang,Yue Cheng,Wen Shen,Baolin Liu,Lixiang Huang,Shuangshuang Xie 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.3

Objective: To investigate brain regional homogeneity (ReHo) changes of multiple sub-frequency bands in cirrhotic patients with or without hepatic encephalopathy using resting-state functional MRI. Materials and Methods: This study recruited 46 cirrhotic patients without clinical hepatic encephalopathy (noHE), 38 cirrhotic patients with clinical hepatic encephalopathy (HE), and 37 healthy volunteers. ReHo differences were analyzed in slow-5 (0.010−0.027 Hz), slow-4 (0.027−0.073 Hz), and slow-3 (0.073−0.198 Hz) bands. Routine analysis of (0.010−0.080 Hz) band was used as a benchmark. Associations of abnormal ReHo values in each frequency band with neuropsychological scores and blood ammonia level were analyzed. Pattern classification analyses were conducted to determine whether ReHo differences in each band could differentiate the three groups of subjects (patients with or without hepatic encephalopathy and healthy controls). Results: Compared to routine analysis, more differences between HE and noHE were observed in slow-5 and slow-4 bands (p < 0.005, cluster > 12, overall corrected p < 0.05). Sub-frequency band analysis also showed that ReHo abnormalities were frequency-dependent (overall corrected p < 0.05). In addition, ReHo abnormalities in each sub-band were correlated with blood ammonia level and neuropsychological scores, especially in the left inferior parietal lobe (overall corrected p < 0.05 for all frequency bands). Pattern classification analysis demonstrated that ReHo differences in lower slow-5 and slow-4 bands (both p < 0.05) and higher slow-3 band could differentiate the three groups (p < 0.05). Compared to routine analysis, ReHo features in slow-4 band obtained better classification accuracy (89%). Conclusion: Cirrhotic patients showed frequency-dependent changes in ReHo. Sub-frequency band analysis is important for understanding HE and clinical monitoring.

N-isopropyl acrylamide/sodium acrylate hydrogel as draw agent for forward osmosis to concentrate esterification wastewater

Yan Le,Yanbin Yun,왕만상,Wenli Liu,Shuangshuang Dong,Kai Yang,Syed Taj Ud Din,Woochul Yang,Guicheng Liu 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.5

In recent years, a temperature-sensitive hydrogel was reported as a promising draw agent in forward osmosis (FO) technology. PEG, acts as porogen, as an enabler to improve the swelling property of hydrogels. From FO test, the addition of porogen to the hydrogel can improve the water flux of FO by increasing the swelling properties of the hydrogel. And the hydrogel modified with porogen improves the concentration efficiency of wastewater from 1.09 to 1.124 times, indicating that the modification of the hydrogel by the porogen has positive significance for FO technology. In this study, an advanced hydrogel was synthesized via physical copolymerization by using N-isopropylacrylamide and sodium acrylate. The internal structure was investigated by SEM test where it was found that that porogens have different mechanisms of action on hydrogel performance: Porogen affects the swelling property of hydrogel by changing the internal network structure through physical “occupation”. The effect of porogen concentration is to act on the porosity of hydrogel, while the main effect of the molecular weight of porogen on the hydrogel structure is by altering the pore size.

Acid–base bifunctional catalysis by a heteropolyacid and amines on the polyetheretherketone fiber for cleaner acceleration of the one-pot tandem reactions

Lijuan Jiang,Xian-Lei Shi,Yue Lv,Honghui Gong,Shuangshuang Liu,Mengmeng Du,Qianqian Hu,Keren Shi 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

The development of highly efficient, economical and environmentally friendly catalytic systems is ofgreat significance from the green chemistry point of view. In this paper, we presented a succinct approachto create a heterogeneous acid–base bifunctional catalyst for one-pot tandem reaction from the commerciallyavailable textile fiber. The ultra-high strength textile fiber polyetheretherketone (PEEK) was functionalizedby a post-grafting method to combine two antagonistic active functions in a synergisticcatalyst, and the resulting fiber samples were characterized in detail by morphology, mechanical properties,elemental analysis, X-ray photoelectron spectroscopy, inductively coupled plasma-atomic emissionspectrometry, X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet–visible spectrum,nuclear magnetic resonance spectroscopy and thermogravimetric analysis, and further revealed thatthe amines and the heteropolyacid were immobilized by acid–base interactions in the PEEK surface layerwith sufficient stability. Moreover, the acid–base bifunctional catalyst can be successfully applied in theacceleration of the one-pot tandem deacetalization–Knoevenagel reactions with high-efficiency (lowercatalyst dosage 0.3 mol%, higher product yields 81–92%), whereas the homogeneous catalysts wereunable to initiate the reaction due to their mutual neutralization in solution, and the catalytic mechanismwas elucidated by comparison. Furthermore, the fibrous catalyst could maintain its activities more than10 cycles with a simple post-processing, and the mediated system was capable of enlarging to the gramscale,which are envisaged for industrial operations and cleaner productions.

Antibacterial properties of natural products from marine fungi reported between 2012 and 2023: a review

Wang Ping,Huang Xiaomei,Jiang Chenyuan,Yang Rushuang,Wu Jialing,Liu Yinghui,Feng Shuangshuang,Wang Tingting 대한약학회 2024 Archives of Pharmacal Research Vol.47 No.6

The oceans are rich in diverse microorganisms, animals, and plants. This vast biological complexity is a major source of unique secondary metabolites. In particular, marine fungi are a promising source of compounds with unique structures and potent antibacterial properties. Over the last decade, substantial progress has been made to identify these valuable antibacterial agents. This review summarizes the chemical structures and antibacterial activities of 223 compounds identified between 2012 and 2023. These compounds, effective against various bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus, exhibit strong potential as antibacterial therapeutics. The review also highlights the relevant challenges in transitioning from drug discovery to product commercialization. Emerging technologies such as metagenomics and synthetic biology are proposed as viable solutions. This paper sets the stage for further research on antibacterial compounds derived from marine fungi and advocates a multidisciplinary approach to combat drug-resistant bacteria.