The mechanism of enhanced photocatalytic activity of SnO2 through fullerene modification

Shuang-Shuang Ding,Wei-Qing Huang,Bing-Xin Zhou,Ping Peng,Wangyu Hu,Meng-Qiu Long,Gui-Fang Huang 한국물리학회 2017 Current Applied Physics Vol.17 No.11

Carbon nanomaterials are prominent building blocks in the synthetic van der Waals (vdW) heterostructures with desired properties. Scientific understanding of their interfacial interactions is the premise to design this kind of vdW heterostructures with optimal performance.We here study the mechanism of enhanced photocatalytic activity of SnO2 by fullerene modification at electronic level, to explore the interfacial interaction and its correlation with photocatalytic activity. The results show that the interfacial interaction increases with the number of C atom of fullerene, and leads to some of C atoms be positively/ negatively charged, making the fullerene a highly active co-catalyst in heterostructures. Compared to pristine SnO2, the band gap of the heterostructures is much smaller, leading to their absorption wavelength extending the entire visible region. Interestingly, a staggered type-II band alignment in the C20 (C60)/SnO2 (101) heterostructures results into the robust separation of photoexcited charge carriers between the two constituents, indicating that the fullerene is an effective sensitizer, and thus enhanced photocatalytic activity. These findings can rationalize the available experiment and will be of broad interest in developing the highly efficient semiconductor photocatalysts via fullerene modification.

The relative contributions of segments and prosody to L1 identification in transplanted L2 speech

Shuang Ding,Joo-Kyeong Lee 한국음운론학회 2020 음성·음운·형태론 연구 Vol.26 No.3

This study attempts to investigate how the foreign accent of L2 speech is correlated with the identification of non-native talkers’ L1s (hereafter, L1 identification) and which factor in L2 speech, segment or prosody, contributes more to L1 identification. In an experiment conducted to determine the correlation between perceived accentedness and L1 identification, it was found that both English native and non-native listeners recognized the talkers’ L1 more precisely for L2 speech with a stronger accent. In an other experiment, segments and prosody were transplanted between Chinese and Korean talkers of English. Listeners varied between English native and non-native Chinese and Korean listeners, and non-native talkers’ and listeners’ English proficiency was varied between high and low. The results show that segments had a greater effect than prosody. However, this didn’t hold true when native listeners listened to low proficiency talkers’ speech composed of Chinese talkers’ prosody and Korean talkers’ segments, or when the segments were derived from the talkers of the same L1 as the listeners. Both showed that non-native talkers’ and listeners’ L1 backgrounds played a role in the L1 identification of L2 speech. Another intriguing finding was that of skewed responses toward native English talkers for high proficiency talkers’ speech. As presented in the results of the first experiment, less accented L2 speech did not provide enough information for L1 identification, while less accented speech produced by high proficiency talkers didn’t have a sufficient amount of phonetic errors or deviances to successfully identify non-native talkers’ L1s. These findings show that non-natives’ L2 proficiency played a significant role in L1 identification. Overall, L1 identification seems to be affected more by segments than prosody, yet still has intricate interactions with L1 backgrounds and L2 proficiency of non-native talkers and listeners.

Structural-based Screening of L-phenylglycine Aminotransferase using L-phenylalanine as the Optimal Amino Donor: Recycling of L-phenylalanine to Produce L-phenylglycine

Shuang Ping Liu,Rui Xia Liu,Jian Mao,Liang Zhang,Zhongyang Ding,Zhenghua Gu,Gui-Yang Shi 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

The aproteinogenic amino acid, L-phenylglycine, is an important side chain building block for some drugs. It would be of great commercial and environmental value to biocatalyse L-phenylalanine to L-phenylglycine, and thus replace the organic synthesis method. To produce Lphenylglycine from L-phenylalanine, an L-phenylglycine aminotransferase was screened and characterized. HpgTAO showed high homology to α-aminoadipate aminotransferase. The L-phenylalanine binding site was near the residues S26, R401, N201, and G46 in HpgTAO, and L-phenylalanine formed a hydrogen bond with Asn20, which was similar to the substrate binding mechanism of α-aminoadipate aminotransferase. HpgTAO showed increased activity in alkalescent environment below 40°C. The kinetic analysis showed that L-phenylalanine had the highest affinity to HpgTAO, which ensured the recycle biosynthesis of Lphenylglycine from L-phenylalanine. To date, it was the only aminotransferase using L-phenylalanine as an optimal amino donor. The L-phenylglycine biocatalysis operon was also constructed by co-expressing the hmaS, hmo and hpgT by a single plasmid. The first in vitro conversion of Lphenylalanine to L-phenylglycine was achieved by directly using the L-phenylalanine fermentation broth as the raw material.

Development of High-specificity Antibodies against Renal Urate Transporters Using Genetic Immunization

( Guo Shuang Xu ),( Xiang Mei Chen ),( Di Wu ),( Suo Zhu Shi ),( Jian Zhong Wang ),( Rui Ding ),( Quan Hong ),( Zhe Feng ),( Shu Peng Lin ),( Yang Lu ) 생화학분자생물학회 2006 BMB Reports Vol.39 No.6

Prolyl endopeptidase remodels macrophage function as a novel transcriptional coregulator and inhibits fibrosis

Lin Shuang-Zhe,Wu Wei-Jie,Cheng Yu-Qing,Zhang Jian-Bin,Jiang Dai-Xi,Ren Tian-Yi,Ding Wen-Jin,Liu Mingxi,Chen Yuan-Wen,Fan Jian-Gao 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Macrophages are immune cells crucial for host defense and homeostasis maintenance, and their dysregulation is involved in multiple pathological conditions, such as liver fibrosis. The transcriptional regulation in macrophage is indispensable for fine-tuning of macrophage functions, but the details have not been fully elucidated. Prolyl endopeptidase (PREP) is a dipeptidyl peptidase with both proteolytic and non-proteolytic functions. In this study, we found that Prep knockout significantly contributed to transcriptomic alterations in quiescent and M1/M2-polarized bone marrow-derived macrophages (BMDMs), as well as aggravated fibrosis in an experimental nonalcoholic steatohepatitis (NASH) model. Mechanistically, PREP predominantly localized to the macrophage nuclei and functioned as a transcriptional coregulator. Using CUT&Tag and co-immunoprecipitation, we found that PREP was mainly distributed in active cis-regulatory genomic regions and physically interacted with the transcription factor PU.1. Among PREP-regulated downstream genes, genes encoding profibrotic cathepsin B and D were overexpressed in BMDMs and fibrotic liver tissue. Our results indicate that PREP in macrophages functions as a transcriptional coregulator that finely tunes macrophage functions, and plays a protective role against liver fibrosis pathogenesis.

Human Intersectin 2 (ITSN2) binds to Eps8 protein and enhances its degradation

( Xiao Feng Ding ),( Zijian Yang ),( Fang Liang Zhou ),( Xiang Huchang ),( Zhou Chang Luo ),( Zhi Cheng He ),( Qian Liu ),( Hong Li ),( Feng Yan ),( Fang Mei Wang ),( Shuang Lin Xiang ),( Jian Zhang ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.3

Participates in actin remodeling through Rac and receptor endocytosis via Rab5. Here, we used yeast two-hybrid system with Eps8 as bait to screen a human brain cDNA library. ITSN2 was identified as the novel binding factor of Eps8. The interaction between ITSN2 and Eps8 was demonstrated by the in vivo co-immunoprecipitation and colocalization assays and the in vitro GST pull-down assays. Furthermore, we mapped the interaction domains to the region between amino acids 260-306 of Eps8 and the coiled-coil domain of ITSN2. In addition, protein stability assays and immunofluorescence analysis showed ITSN2 overexpression induced the degradation of Eps8 proteins, which was markedly alleviated with the lysosome inhibitor NH4Cl treatment. Taken together, our results suggested ITSN2 interacts with Eps8 and stimulates the degradation of Eps8 proteins. [BMB reports 2012; 45(3): 183-188]

Causal relationship between smoking status, smoking frequency and bladder cancer: a Mendelian randomization study

Pang Lei,Ding Zijun,Chai Hongqiang,Li Fei,Wu Ming,Shuang Weibing 한국유전학회 2023 Genes & Genomics Vol.45 No.2

Background Smoking is a well-established risk factor for bladder cancer. However, it remained unclear that whether smoke status and smoke frequency increase bladder cancer. Objective We aim to explore the causal relationship between smoking status, smoking frequency and the risk of bladder cancer by Mendelian randomization. Methods Large sample size of the genome-wide association(GWAS) database of smoking status, smoking frequency and bladder cancer were obtained. Smoking status included never, previous and current whereas smoking frequency included cigarettes smoked per day, number of cigarettes currently smoked daily and pack years of smoking. Six sets of instrumental variables and 78 related single nucleotide polymorphic(SNP) loci were identified (P < 5 × 10–8. Linkage disequilibrium R2 < 0.001). The causal relationship between smoking status and bladder tumor was studied by inverse variance weighted (IVW), weighted median and MR-Egger regression. Sensitivity analysis were also performed. Results There is no causal effect from smoke status on bladder cancer risk while significantly positive relationship between smoking frequency on bladder cancer risk were found. IVW results showed that cigarettes smoked per day, number of cigarettes currently smoked daily and pack years of smoking increase bladder cancer (OR 1.001, 95% CI 1.000–1.002, P = 0.047; OR 1.003, 95% CI 1.000–1.005, P = 0.028; OR 1.004, 95% CI 1.001–1.006, P = 0.003). Sensitivity analysis showed that genetic pleiotropy did not bias the results. Conclusion The results of two sample Mendelian randomization analysis show that there is a positive causal relationship between smoking frequency and the risk of bladder cancer.

Coupled electro-elastic analysis of functionally graded piezoelectric material plates

Chih-Ping Wu,Shuang Ding 국제구조공학회 2015 Smart Structures and Systems, An International Jou Vol.16 No.5

A unified formulation of finite layer methods (FLMs), based on the Reissner mixed variational theorem (RMVT), is developed for the three-dimensional (3D) coupled electro-elastic analysis of simply-supported, functionally graded piezoelectric material (FGPM) plates with open- and closed-circuit surface conditions and under electro-mechanical loads. In this formulation, the material properties of the plate are assumed to obey an exponent-law varying exponentially through the thickness coordinate, and the plate is divided into a number of finite rectangular layers, in which the trigonometric functions and Lagrange polynomials are used to interpolate the in- and out-of-plane variations of the primary field variables of each individual layer, respectively, such as the elastic displacement, transverse shear and normal stress, electric potential, and normal electric displacement components. The relevant orders used for expanding these variables in the thickness coordinate can be freely chosen as the linear, quadratic and cubic orders. Four different mechanical/electrical loading conditions applied on the top and bottom surfaces of the plate are considered, and the corresponding coupled electro-elastic analysis of the loaded FGPM plates is undertaken. The accuracy and convergence rate of the RMVT-based FLMs are assessed by comparing their solutions with the exact 3D piezoelectricity ones available in the literature.

CK2 phosphorylates AP-2α and increases its transcriptional activity

( Kai Qun Ren ),( Shuang Lin Xiang ),( Fang Li He ),( Wen Feng Zhang ),( Xiao Feng Ding ),( Yan Yang Wu ),( Li Ping Yang ),( Jian Lin Zhou ),( Xiang Gao ),( Jian Zhang ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.7

Transcription factor AP-2α involves in the process of mammalian embryonic development and tumorigenesis. Many studies have shown that AP-2α functions in association with other interacting proteins. In a two-hybrid screening, the regulatory subunit β of protein casein kinase 2 (CK2β) was identified as an interacting protein of AP-2α; we confirmed this interaction using in-vitro GST pull-down and in-vivo co-immunoprecipitation assays; in an endogenous co-immunoprecipitation experiment, we further found the catalytic subunit α of protein casein kinase 2 (CK2α) also exists in the complex. Phosphorylation analysis revealed that AP-2α was phosphorylated by CK2 kinase majorly at the site of Ser429, and such phosphorylation could be blocked by CK2 specific inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) in a dose-dependent manner. Luciferase assays demonstrated that both CK2α and CK2β enhanced the transcription activity of AP-2α; moreover, CK2β increased the stability of AP-2α. Our data suggest a novel cellular function of CK-2 as a transcriptional co-activator of AP-2α.

Screening and Anti-virulent Study of N-Acyl Homoserine Lactones DNA Aptamers against Pseudomonas aeruginosa Quorum Sensing

Zu-Guo Zhao,Yun Mei Yu,Bi Yu Xu,Shuang-Shuang Yan,Jun-Fa Xu,Fang Liu,Guo-Ming Li,Yuan Lin Ding,Shu Qing Wu 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

In Pseudomonas aeruginosa, a quorum sensing (QS) system regulates the expression of many virulence factors. N-acyl homoserine lactone (HSL) is the signal molecule of QS system. In order to find a novel HSL binder to interfere with QS signaling and to attenuate P. aeruginosa virulence, an amino lactam surrogate (ALS) of HSL was used as a target to screen HSL aptamers with the technique of systematic evolution of ligands by exponential enrichment (SELEX). Eight HSL aptamers with high affinities for 3O-C12-HSL (20 nM ≤ Kd < 35 nM) or C4-HSL (25 nM < Kd < 50 nM) were finally obtained. In vitro QS-inhibiting study of P. aeruginosa showed that HSL aptamers could inhibit virulence in a dose-dependent manner. ALSap-8 which bound C4-HSL primarily acted on the rhl system and inhibited the secretion of pyocyanin. ALSap-5 which bound 3O-C12-HSL not only showed strong inhibitory activity on biofilm formation as well as secretions of LasA protease and LasB elastase, but also reduced pyocyanin secretion. Since the las system is capable of activating the rhl system mildly, we speculated that ALSap-5 can simultaneously interfere with the las and rhl systems. High-affinity aptamers against HSL in this study are novel QS and virulence-inhibitors, and may have potential as drug candidates for the treatment of P. aeruginosa infection.