Browsing by Author "Chen, Bo-Han"

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Effect of morphology of mesoporous silica on characterization of protic ionic liquid-based composite membranes
(2011-07-01)
Ye, Yun-Sheng
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Liang, Gao-Wei
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Chen, Bo-Han
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Shen, Wei-Chung
;
Tseng, Chi-Yung
Effects caused by the morphology of mesoporous silica on the characterization of protic ionic liquid-based composite membranes for anhydrous proton exchange membrane applications are investigated. Two types of SBA15 materials with platelet and fiberlike morphologies are synthesized and incorporated into a mixture of polymerizable monomers together with an ionic liquid (IL)[1-butyl-3-methylimidazolium bis(trifluoromethane sulfone)imide (BMIm-TFSI)] to form new conducting membranes using an in situ photo crosslinking process. Incorporation of a defined amount of fiber-shaped SBA 15 and platelet 15 significantly increases the ionic conductivity to between two and three times that of a plain poly(methyl methacrylate) (PMMA)/IL membrane (2.3 mS cm(-1)) at 160 degrees C. The protic ionic liquid (PIL) retention ability of the membranes is increased by the capillary forces introduced by the mesoporous silica materials, while ionic conductivity loss after leaching test is retarded. The highest ionic conductivity (5.3 mS cm(-1)) is obtained by incorporating 5 wt% of P-SBA 15 in the membrane to about six times that of plain PMMA/IL membrane (0.9 mS cm(-1)) at 160 degrees C after leaching test. (C) 2011 Elsevier B.V. All rights reserved.
Fluorescence assay for protein post-translational tyrosine sulfation
(2013-02-01)
Chen, Bo-Han
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Wang, Chen-Chu
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Lu, Lu-Yi
;
Hung, Kuo-Sheng
;
Yang, Yuh-Shyong
We developed a fluorescent assay to conveniently determine the kinetics of protein sulfation, which is essential for understanding interface between protein sulfation and protein-protein interactions. Tyrosylprotein sulfotransferase (TPST) catalyzes protein sulfation using 3'-phosphate 5'-phosphosulfate (PAPS) as sulfuryl group donor. In this report, PAPS was regenerated following sulfuryl group transfer between adenosine 3',5'-diphosphate and 4-methylumbelliferyl sulfate catalyzed by phenol sulfotransferase (PST). The TPST and PST coupled enzyme platform continuously generated fluorescent 4-methylumbelliferone (MU) that was used to real-time monitor protein sulfation. Using a recombinant N utilization substance protein A fused Drosophila melanogaster tyrosylprotein sulfotransferase, we demonstrated that the activity of TPST determined through MU fluorescence directly correlated with protein sulfation. Kinetic constants obtained with small P-selectin glycoprotein ligand-1 peptide (PSGL-1 peptide, MW 1541) or its large glutathione S-transferase fusion protein (GST-PSGL-1, MW 27833) exhibited significant variation. This assay can be further developed to a high-throughput method for the characterization of TPSTs and for the identification and screening of their protein substrates.
High-Throughput Screening of Sulfated Proteins by Using a Genome-Wide Proteome Microarray and Protein Tyrosine Sulfation System
(2017-03-21)
Huang, Bo-Yu
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Chen, Po-Chung
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Chen, Bo-Han
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Wang, Chen-Chu
;
Liu, Hsuan-Fu
Protein tyrosine sulfation (PTS) is a widespread posttranslational modification that induces intercellular and extracellular responses by regulating protein protein interactions and enzymatic activity. Although PTS affects numerous physiological and pathological processes, only a small fraction of the total predicted sulfated proteins has been identified to date. Here, we localized the potential sulfation sites of Escherichia coli proteins on a proteome microarray by using a 3'-phosphoadenosine 5'-phosphosulfate (PAPS) synthase-coupled tyrosylprotein sulfotransferase (TPST) catalysis system that involves in situ PAPS generation and TPST catalysis. Among the 4256 E. coil K12 proteins, 875 sulfated proteins were identified using antisulfotyrosine primary and Cy3-labeled antimouse secondary antibodies. Our findings add considerably to the list of potential proteins subjected to tyrosine sulfation. Similar procedures can be applied to identify sulfated proteins in yeast and human proteome microarrays, and we expect such approaches to contribute substantially to the understanding of important human diseases.
Implantation of Post-translational Tyrosylprotein Sulfation into a Prokaryotic Expression System
(2011-02-11)
Lu, Lu-Yi
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Chen, Bo-Han
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Wu, Jennifer Yun-Shin
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Wang, Chen-Chu
;
Chen, Da-Huang
Mechanism of sulfotransferase pharrnacogenetics in altered xenobiotic metabolism
(2015-07-01)
Chen, Bo-Han
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Wang, Chen-Chu
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Hou, You-Hua
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Mao, Yi-Chih
;
Yang, Yuh-Shyong
Introduction: Cytosolic sulfotransferases (SULTs), one of the vital enzymes of detoxication, catalyze the sulfation of native and exogenous hydrophobic molecules. Xenobiotic accumulation can induce a variety of diseases, including cancers. Sulfation facilitates the solubilization and removal of xenobiotics. However, sulfation may activate the pharmacological-activities of xenobiotics. Areas covered: The purpose of this review was to correlate the sequence, structure and function of SULTs. We focused on understanding the sulfation mechanisms of SULT through its sequence variation. We selectively reviewed SULT drug substrates, explained the enzyme-catalyzed sulfation reaction and its kinetic mechanisms, and the effect of amino acid sequence variation, such as single-nucleotide polymorphism, on the enzyme function. Expert opinion: A wealth of information is available in the literature for understanding the detailed mechanisms underlying xenobiotic sulfation. We reviewed information regarding the sequence, structure and reaction mechanism of SULTs and explained how SULT activities altered. In addition to revealing the SULT kinetics, the mRNA expression of specific SULTs in tissues that revealed their distribution in tissues also affects overall SULT activities. Understanding of the structure-function relationship and the reaction mechanism of SULTs is valuable for understanding, preventing and treating diseases.
Preparation of Tyrosylprotein Sulfotransferases for In Vitro One-Pot Enzymatic Synthesis of Sulfated Proteins/Peptides
(2018-09-01)
Wang, Chen-Chu
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Chen, Bo-Han
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Lu, Lu-Yi
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Hung, Kuo-Sheng
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Yang, Yuh-Shyong
Protein tyrosine sulfahon (PTS), catalyzed by meinbraneanchored tyrosylprotein sulfotransferase (TPST), is one of the most common post-translational modifications of secretory and transmembrane proteins. PTS, a key modulator of extracellular protein proteininteractions, accounts for various important biological activities, namely, virus entry, inflammation, coagulation, and sterility. The preparation and characterization of TPST is fundamental for understanding the synthesis of tyrosine-sulfated proteins and for studying PTS in biology. A sulfated protein was prepared using a TPSTT coupled protein sulfation system that involves the generation of the active sulfate 31-phosphoadenosine-51-phosphosulfate (PAPS) through either PAPS synthetase (PAPSS) or phenol sulfotransferase. The preparation of sulfated proteins was confirmed through radiometric or immunochemical assays. In this study, enzymatically active Drosophila melanogaster TPST (DruTPST) and human TPSTs (hTPST1 and hTPST2) were expressed in Escherichia colt BL21(DE3) host cells and purified to homogeneity in high yield. Our results revealed that recombinant DmTPST was particularly useful considering its catalytic efficiency and ease of preparation in large quantities. This study provides tools for high-efficiency, one-step synthesis of sulfated proteim arid peptides that are useful for further deciphering the mechanisms, functions, and future applications of PTS.
QUALITY INSPECTION OF PHALAENOPSIS HYBRIDS USING HYPERSPECTRAL BAND SELECTION TECHNIQUES
(2019-01-01)
Ouyang, Yen-Chieh
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Chen, Bo-Han
;
Lee, Meng-Chueh
;
Liu, Tsang-Sen
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Ou-Yang, Mang
Fusarium wilt on Phalaenopsis is a disease that makes farmers suffer seriously. Although Phalaenopsis does not die immediately with Fusarium wilt, it seriously decreases the quality that buyers cannot accept. In this paper, we introduce an emerging method to detect Fusarium wilt at the base of Phalaenopsis stems. The detection model divides Phalaenopsis samples into two categories, healthy and infection. The band selection (BS) processing technique based on band prioritization (BP) is applied to extract significant bands and eliminate redundant bands. Subsequently, some algorithms which are constrained energy minimization (CEM), spectral information divergence(SID) and SeQuential N-FINDER to detect the Fusarium wilt, and we hope the research would help farmers decrease their losses.
Surface composition and interactions of mobile charges with immobilized molecules on polycrystalline silicon nanowires
(2015-05-01)
Lin, Chih-Heng
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Feng, Mei-Huei
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Hwang, Chi-Hung
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Wu, Jennifer Yun-Shin
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Su, Ping-Chia
The polycrystalline silicon nanowire field-effect transistor (poly-SiNW FET) is one of the most sensitive sensors used in real-time and label-free biosensing applications. Its low power requirement, mass production potential, and integrability with electronic components make it a highly attractive device in the rapidly growing diagnostic research field. From the viewpoint of device physics, the charges in the vicinity of a nanowire (NW) surface modulate the electrical characteristics of the NW device. The charges can originate from surface molecules or an ionic solution, and their role in NW biosensing systems remains to be clarified. Determining their role is crucial for understanding the physical interactions of charges in a biosensing event and for the realization of NW-based biosensors. Therefore, using poly-SiNW FET, we investigated the interactions of the immobilized molecules on the NW surface with the mobile charges in solutions. We also investigated the interactions between the mobile charged polymers and the immobilized molecules on the NW surface, and we observed the effect of charge neutrality, originating from Coulomb charge-charge interactions, on the NW conductance. Finally, the isoelectric points between native and sulfated PSGL-1 peptides on the NW surface were identified. This study provides a physical understanding of the charge-charge interaction of mobile charges with immobilized charged molecules on a nanoscale surface and presents new opportunities for using charge-based detection in biological and chemical sensing applications. (C) 2015 Elsevier B.V. All rights reserved.
Tyrosine Sulfation as a Protein Post-Translational Modification
(2015-02-01)
Yang, Yuh-Shyong
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Wang, Chen-Chu
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Chen, Bo-Han
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Hou, You-Hua
;
Hung, Kuo-Sheng
Integration of inorganic sulfate into biological molecules plays an important role in biological systems and is directly involved in the instigation of diseases. Protein tyrosine sulfation (PTS) is a common post-translational modification that was first reported in the literature fifty years ago. However, the significance of PTS under physiological conditions and its link to diseases have just begun to be appreciated in recent years. PTS is catalyzed by tyrosylprotein sulfotransferase (TPST) through transfer of an activated sulfate from 3'-phosphoadenosine-5'-phosphosulfate to tyrosine in a variety of proteins and peptides. Currently, only a small fraction of sulfated proteins is known and the understanding of the biological sulfation mechanisms is still in progress. In this review, we give an introductory and selective brief review of PTS and then summarize the basic biochemical information including the activity and the preparation of TPST, methods for the determination of PTS, and kinetics and reaction mechanism of TPST. This information is fundamental for the further exploration of the function of PTS that induces protein-protein interactions and the subsequent biochemical and physiological reactions.