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Hussien MK, Sabbah A, Qorbani M, Putikam R, Kholimatussadiah S, Tzou DLM, Elsayed MH, Lu YJ, Wang YY, Lee XH, Lin TY, Thang NQ, Wu HL, Haw SC, Wu KCW, Lin MC, Chen KH, Chen LC. Constructing B─N─P Bonds in Ultrathin Holey g-C 3N 4 for Regulating the Local Chemical Environment in Photocatalytic CO 2 Reduction to CO. Small 2024:e2400724. [PMID: 38639018 DOI: 10.1002/smll.202400724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/10/2024] [Indexed: 04/20/2024]
Abstract
The lack of intrinsic active sites for photocatalytic CO2 reduction reaction (CO2RR) and fast recombination rate of charge carriers are the main obstacles to achieving high photocatalytic activity. In this work, a novel phosphorus and boron binary-doped graphitic carbon nitride, highly porous material that exhibits powerful photocatalytic CO2 reduction activity, specifically toward selective CO generation, is disclosed. The coexistence of Lewis-acidic and Lewis-basic sites plays a key role in tuning the electronic structure, promoting charge distribution, extending light-harvesting ability, and promoting dissociation of excitons into active carriers. Porosity and dual dopants create local chemical environments that activate the pyridinic nitrogen atom between the phosphorus and boron atoms on the exposed surface, enabling it to function as an active site for CO2RR. The P-N-B triad is found to lower the activation barrier for reduction of CO2 by stabilizing the COOH reaction intermediate and altering the rate-determining step. As a result, CO yield increased to 22.45 µmol g-1 h-1 under visible light irradiation, which is ≈12 times larger than that of pristine graphitic carbon nitride. This study provides insights into the mechanism of charge carrier dynamics and active site determination, contributing to the understanding of the photocatalytic CO2RR mechanism.
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Affiliation(s)
- Mahmoud Kamal Hussien
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Department of Chemistry, Faculty of Science, Assiut University, Assiut, 71516, Egypt
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Amr Sabbah
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Tabbin Institute for Metallurgical Studies, Tabbin, Helwan 109, Cairo, 11421, Egypt
- Center of Atomic Initiative for New Materials, National Taiwan University, Taipei, 10617, Taiwan
| | - Mohammad Qorbani
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Center of Atomic Initiative for New Materials, National Taiwan University, Taipei, 10617, Taiwan
| | - Raghunath Putikam
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Septia Kholimatussadiah
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Center of Atomic Initiative for New Materials, National Taiwan University, Taipei, 10617, Taiwan
- Nano Science and Technology, Taiwan International Graduate Program, Academia Sinica, Taipei, 11529, Taiwan
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Mohamed Hammad Elsayed
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
- Department of Chemistry, Faculty of Science, Al-Azhar University, Cairo, 11884, Egypt
| | - Yu-Jung Lu
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
- Research Center for Applied Science, Academia Sinica, Taipei, 11529, Taiwan
| | - Yen-Yu Wang
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
- Research Center for Applied Science, Academia Sinica, Taipei, 11529, Taiwan
| | - Xing-Hao Lee
- Research Center for Applied Science, Academia Sinica, Taipei, 11529, Taiwan
| | - Tsai-Yu Lin
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Center of Atomic Initiative for New Materials, National Taiwan University, Taipei, 10617, Taiwan
- Molecular Science and Technology Program, Taiwan International Graduate Program (TIGP), Academia Sinica, Taipei, 11529, Taiwan
- International Graduate Program of Molecular Science and Technology, National Taiwan University (NTU-MST), Taipei, 10617, Taiwan
| | - Nguyen Quoc Thang
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Heng-Liang Wu
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Center of Atomic Initiative for New Materials, National Taiwan University, Taipei, 10617, Taiwan
| | - Shu-Chih Haw
- Nano-science Group, National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Kevin C-W Wu
- Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Ming-Chang Lin
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Kuei-Hsien Chen
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Li-Chyong Chen
- Center for Condensed Matter Sciences, National Taiwan University, Taipei, 10617, Taiwan
- Center of Atomic Initiative for New Materials, National Taiwan University, Taipei, 10617, Taiwan
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
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2
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Jian CB, Wu YY, Lin MH, Gao HD, Chen CY, Leong SK, Tzou DLM, Hwang DW, Lee HM. A Facile NMR Method for Pre-MRI Evaluation of Trigger-Responsive T 1 Contrast Enhancement. Small Methods 2024:e2301603. [PMID: 38459640 DOI: 10.1002/smtd.202301603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/09/2024] [Indexed: 03/10/2024]
Abstract
There is a growing interest in developing paramagnetic nanoparticles as responsive magnetic resonance imaging (MRI) contrast agents, which feature switchable T1 image contrast of water protons upon biochemical cues for better discerning diseases. However, performing an MRI is pragmatically limited by its cost and availability. Hence, a facile, routine method for measuring the T1 contrast is highly desired in early-stage development. This work presents a single-point inversion recovery (IR) nuclear magnetic resonance (NMR) method that can rapidly evaluate T1 contrast change by employing a single, optimized IR pulse sequence that minimizes water signal for "off-state" nanoparticles and allows for sensitively measuring the signal change with "switch-on" T1 contrast. Using peptide-induced liposomal gadopentetic acid (Gd3+ -DTPA) release and redox-sensitive manganese oxide (MnO2 ) nanoparticles as a demonstration of generality, this method successfully evaluates the T1 shortening of water protons caused by liposomal Gd3+ -DTPA release and Mn2+ formation from MnO2 reduction. Furthermore, the NMR measurement is highly correlated to T1 -weighted MRI scans, suggesting its feasibility to predict the MRI results at the same field strength. This NMR method can be a low-cost, time-saving alternative for pre-MRI evaluation for a diversity of responsive T1 contrast systems.
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Affiliation(s)
- Cheng-Bang Jian
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
- Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Taipei, 11529, Taiwan
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Ying-Yann Wu
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Ming-Huang Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Hua-De Gao
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Chong-Yan Chen
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Shwee Khuan Leong
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Yang Ming Chiao Tung University, Taipei, 11529, Taiwan
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu, 30093, Taiwan
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Dennis W Hwang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Hsien-Ming Lee
- Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan
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3
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Kao CF, Liu CY, Hsieh CL, Carillo KJD, Tzou DLM, Wang HC, Chang W. Structural and functional analyses of viral H2 protein of the vaccinia virus entry fusion complex. J Virol 2023; 97:e0134323. [PMID: 37975688 PMCID: PMC10734489 DOI: 10.1128/jvi.01343-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/02/2023] [Indexed: 11/19/2023] Open
Abstract
IMPORTANCE Vaccinia virus infection requires virus-cell membrane fusion to complete entry during endocytosis; however, it contains a large viral fusion protein complex of 11 viral proteins that share no structure or sequence homology to all the known viral fusion proteins, including type I, II, and III fusion proteins. It is thus very challenging to investigate how the vaccinia fusion complex works to trigger membrane fusion with host cells. In this study, we crystallized the ectodomain of vaccinia H2 protein, one component of the viral fusion complex. Furthermore, we performed a series of mutational, biochemical, and molecular analyses and identified two surface loops containing 170LGYSG174 and 125RRGTGDAW132 as the A28-binding region. We also showed that residues in the N-terminal helical region (amino acids 51-90) are also important for H2 function.
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Affiliation(s)
- Chi-Fei Kao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Chang-Yi Liu
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Chia-Lin Hsieh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | | | | | - Hao-Ching Wang
- The PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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4
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Bedasso GD, Tzou DLM, Chung PW. Amino group functionalized pitch-based carbocatalyst for the Henry reaction of furfural. J Taiwan Inst Chem Eng 2023. [DOI: 10.1016/j.jtice.2023.104801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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5
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Yu SSF, Lu YJ, Janmanchi D, Thiyagarajan N, Lin ZH, Wanna WH, Hsu IJ, Tzou DLM, Abay TA. Silver cyanide powder‐catalyzed selective epoxidation of cyclohexene and styrene with its surface activation by H₂O₂(aq) and assisted by CH₃CN as a non‐innocent solvent. ChemCatChem 2022. [DOI: 10.1002/cctc.202200030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Steve S.-F. Yu
- Academia Sinica Institute of Chemistry Academia Road 115 Taipei TAIWAN
| | - Yu-Jhang Lu
- Institute of Chemistry Academia Sinica Institute of Chemistry TAIWAN
| | - Damodar Janmanchi
- Institute of Chemistry Academia Sinica Institute of Chemistry TAIWAN
| | | | - Zhi-Han Lin
- Institute of Chemistry Academia Sinica Institute of Chemistry TAIWAN
| | | | - I-Jui Hsu
- National Taipei University of Technology Department of Molecular Science and Engineering TAIWAN
| | - Der-Lii M. Tzou
- Institute of Chemistry Academia Sinica Institute of Chemistry TAIWAN
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6
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Wang C, Li JR, Li Y, Tu HL, Tzou DLM, Wang CM. Stable Crystalline Organic-Inorganic Hybrid Indium Phosphate with Dye Removal and Ractopamine Detection Applications. Inorg Chem 2021; 60:11655-11660. [PMID: 34283911 DOI: 10.1021/acs.inorgchem.1c01664] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A highly stable framework of an organic-inorganic hybrid indium phosphate (NTOU-7) was synthesized under hydro(solvo)thermal conditions and structurally characterized by single-crystal X-ray diffraction and solid-state NMR spectroscopy. This is the first example of a post-transition-metal phosphate incorporating tetradentate organic molecules. The In atoms in the inorganic layers are coordinated by imidazole rings of the 1,2,4,5-tetrakis(imidazol-1-ylmethyl)benzene linkers to generate a new solid-state material. NTOU-7 showed high chemical stability and displayed excellent performance for both dye removal and ractopamine (RAC) detection, which are interesting environmental and biosensing applications. The sensitivity and ultralow limit of detection were 607.9 μA·μM·cm-2 and 2.74 × 10-10 mol·L-1 (0.08 ppb), which meet the requirements stated by the Codex Alimentarius Commission (10 ppb RAC residue in beef and pork). The detection performance was confirmed by sensing spiked-in RAC in real pork samples. We also reported the synthesis, characterization, structural stability, dye removal, and sensing properties of NTOU-7.
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Affiliation(s)
- Chu Wang
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202, Taiwan, Republic of China
| | - Jia-Rong Li
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202, Taiwan, Republic of China
| | - Ying Li
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202, Taiwan, Republic of China.,Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan, Republic of China
| | - Hsiung-Lin Tu
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan, Republic of China
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan, Republic of China
| | - Chih-Min Wang
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 202, Taiwan, Republic of China.,General Education Center, National Taiwan Ocean University, Keelung 202, Taiwan, Republic of China
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7
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Wu D, Carillo KJ, Shie JJ, Yu SSF, Tzou DLM. Resolving Entangled JH-H-Coupling Patterns for Steroidal Structure Determinations by NMR Spectroscopy. Molecules 2021; 26:molecules26092643. [PMID: 33946512 PMCID: PMC8124291 DOI: 10.3390/molecules26092643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 11/16/2022] Open
Abstract
For decades, high-resolution 1H NMR spectroscopy has been routinely utilized to analyze both naturally occurring steroid hormones and synthetic steroids, which play important roles in regulating physiological functions in humans. Because the 1H signals are inevitably superimposed and entangled with various JH–H splitting patterns, such that the individual 1H chemical shift and associated JH–H coupling identities are hardly resolved. Given this, applications of thess information for elucidating steroidal molecular structures and steroid/ligand interactions at the atomic level were largely restricted. To overcome, we devoted to unraveling the entangled JH–H splitting patterns of two similar steroidal compounds having fully unsaturated protons, i.e., androstanolone and epiandrosterone (denoted as 1 and 2, respectively), in which only hydroxyl and ketone substituents attached to C3 and C17 were interchanged. Here we demonstrated that the JH–H values deduced from 1 and 2 are universal and applicable to other steroids, such as testosterone, 3β, 21-dihydroxygregna-5-en-20-one, prednisolone, and estradiol. On the other hand, the 1H chemical shifts may deviate substantially from sample to sample. In this communication, we propose a simple but novel scheme for resolving the complicate JH–H splitting patterns and 1H chemical shifts, aiming for steroidal structure determinations.
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Affiliation(s)
- Danni Wu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan; (D.W.); (K.J.C.); (J.-J.S.); (S.S.-F.Y.)
| | - Kathleen Joyce Carillo
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan; (D.W.); (K.J.C.); (J.-J.S.); (S.S.-F.Y.)
- International Graduate Program, SCST, Academia Sinica, Nankang, Taipei 11529, Taiwan
- The Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 30013, Taiwan
| | - Jiun-Jie Shie
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan; (D.W.); (K.J.C.); (J.-J.S.); (S.S.-F.Y.)
| | - Steve S.-F. Yu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan; (D.W.); (K.J.C.); (J.-J.S.); (S.S.-F.Y.)
| | - Der-Lii M. Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan; (D.W.); (K.J.C.); (J.-J.S.); (S.S.-F.Y.)
- Department of Applied Chemistry, National Chia-Yi University, Chia-Yi 60004, Taiwan
- Correspondence:
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Wu D, Lou YC, Chang W, Tzou DLM. NMR assignments of vaccinia virus protein A28: an entry-fusion complex component. Biomol NMR Assign 2021; 15:117-120. [PMID: 33398629 DOI: 10.1007/s12104-020-09993-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Vaccinia virus (VACV) belonging to the poxvirus family enters the host cell via two different entry pathways; either endocytosis or virus/host cell membrane fusion. With respect to the virus/host cell membrane fusion, there are eleven viral membrane proteins forming a complicated entry-fusion complex (EFC), including A28, A21, A16, F9, G9, G3, H2, J5, L5, L1 and O3, to conduct the fusion function. These EFC components are highly conserved in all poxviruses and each of them is essential and necessary for the fusion activity. So far, with the exceptions of L1 and F9 whose crystal structures were reported, the structural information about other EFC components remains largely unclear. We aim to conduct a structural and functional investigation of VACV virus-entry membrane protein A28. In this work, we expressed and purified a truncated form of A28 (14 kDa; residues 38-146, abbreviated as tA28 hereinafter), with deletion of its transmembrane domain (residues 1-22) and a hydrophobic segment (residues 23-37). And the assignments of its backbone and side chain 1H, 13C and 15N chemical shifts of tA28 are reported. The secondary structure propensity from TALOS+ indicates that tA28 does contain three α-helices, six β-strands and connecting loops. Aside from this, we demonstrated that tA28 does interact with fusion suppressor viral protein A26 (residues 351-500) by the 1H-15N HSQC spectrum. We interpret that A28 binding to A26 deactivates EFC fusion activity. The current study provides a valuable framework towards further structural analyses of this protein and for better understanding virus/host cell membrane fusion mechanism in association with virus entry.
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Affiliation(s)
- Danni Wu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
| | - Yuan-Chao Lou
- Biomedical Translation Research Center, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
| | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC.
- Biomedical Translation Research Center, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC.
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9
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Štěrbová P, Wu D, Lou YC, Wang CH, Chang WH, Tzou DLM. NMR assignments of protrusion domain of capsid protein from dragon grouper nervous necrosis virus. Biomol NMR Assign 2020; 14:63-66. [PMID: 31848940 DOI: 10.1007/s12104-019-09921-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
Nervous necrosis virus (NNV) is a non-enveloped virus that causes massive mortality in aquaculture fish production worldwide. Recently X-ray crystallography and single particle cryo-EM have independently determined the icosahedral capsid of NNV to near-atomic resolutions to show the capsid protein is composed of a S-domain (shell) and a P-domain (protrusion) connected by a linker. However, the structure of the spike on NNV capsid made of trimeric P-domains was poorly resolved by cryo-EM. In addition, comparing the spike in the cryo-EM with that by X-ray suggests that the P-domain can move drastically relative to the shell, implicating an underlying structural mechanism during the infectious process. Yet, it remains unclear that such structural re-arrangement is ascribed to the change of the conformation of individual P-domain or in the association among P-domains. Given that molecular structure of the P-domain in solution phase is still lacking, we aim to determine the structure of the P-domain by solution NMR spectroscopy. In this communication, we report backbone and side chain 1H, 13C and 15N chemical shifts of the P-domain (residues 221-338) together with the linker region (residues 214-220), revealing ten β-strands via chemical shift propensity analysis. Our findings are consistent with the X-ray crystal structure of the P-domain reported elsewhere. The current study provides a framework towards further structural analyses of the P-domain in various solution conditions.
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Affiliation(s)
- Petra Štěrbová
- Chemical Biology and Molecular Biophysics, Taiwan International Graduate Program, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
- College of Life Science, National Tsing Hua University, Hsinchu, 30013, Taiwan, ROC
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
| | - Danni Wu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
| | - Yuan-Chao Lou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
| | - Chun-Hsiung Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC
| | - Wei-Hau Chang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC.
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei, 11529, Taiwan, ROC.
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10
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Carillo KJD, Wu D, Lin SC, Tsai SL, Shie JJ, Tzou DLM. 1H/ 13C chemical shifts and cation binding dataset of the corticosteroid Prednisolone titrated with metal cations. Data Brief 2019; 27:104620. [PMID: 31687439 PMCID: PMC6820118 DOI: 10.1016/j.dib.2019.104620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/09/2019] [Accepted: 09/26/2019] [Indexed: 11/09/2022] Open
Abstract
We here reported the 1H/13C chemical shifts, binding affinity and binding free energy of 1,4-pregnadiene-11β,17α,21-triol-3,20-dione (Prednisolone; Prd) interacting with metal cations. Six different Prd/Ni or Co mixtures were examined at different molar ratios (1:0, 1:0.1, 1:0.2, 1:0.3, 1:0.4 and 1:0.5). In this analysis, the 1H and 13C chemical shifts were measured for the Prd/cation mixtures using a Bruker AV 500 MHz spectrometer (Bruker BioSpin GmbH, Rheinstetten, Germany), equipped with a 5 mm z-gradient Prodigy BBO 500 MHz probehead at 298 K, and simulation of the 1H spectra were determined from the Daisy software package (Bruker BioSpin GmbH). Binding affinity and free energy values were deduced from the 13C NMR peak intensities involved in the cation interaction, for more insight on the steroid/cation interactions please see Magnesium and Calcium Reveal Different Chelating Effects in a Steroid Compound: A Model Study of Prednisolone Using NMR Spectroscopy [1].
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Affiliation(s)
- Kathleen Joyce D Carillo
- Taiwan International Graduate Program - SCST, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.,Department of Applied Chemistry, National Chiao-Tung University, Hsinchu 30013, Taiwan, ROC.,Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Danni Wu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Su-Ching Lin
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Shen-Long Tsai
- Chemical Engineering Department of NTUST, Taipei 10607, Taiwan, ROC
| | - Jiun-Jie Shie
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.,Department of Applied Chemistry, National Chia-Yi University, Chia-Yi 60004, Taiwan, ROC
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11
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Carillo KD, Wu D, Lin SC, Tsai SL, Shie JJ, Tzou DLM. Magnesium and calcium reveal different chelating effects in a steroid compound: A model study of prednisolone using NMR spectroscopy. Steroids 2019; 150:108429. [PMID: 31229509 DOI: 10.1016/j.steroids.2019.108429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/16/2019] [Accepted: 06/17/2019] [Indexed: 11/21/2022]
Abstract
In this work, we used high resolution NMR spectroscopy to investigate metal cation chelation by the steroidal drug 1,4-pregnadiene-11β,17α,21-triol-3,20-dione (Prednisolone; abbreviated as Prd). Prd/MgCl2 and Prd/CaCl2 mixtures were prepared at eight different molar ratios. Using two-dimensional 1H/13C heteronuclear correlation spectroscopy, we were able to resolve most of the 1H signals, except those at 1.4-1.55 ppm, where signals for H15β, H16α and Me-19 are superimposed. The chelation sites were determined by the cation concentration-dependent 13C signals. Both ring A and ring D of Prd were found to be involved in Mg2+ chelation, whereas only ring A was involved in Ca2+ chelation. The dihedral angles deduced from the 3JH-H coupling constants indicated that ring D of Prd might undergo rather small, but different, distortions in the presence of Mg2+ and Ca2+. Additionally, using the continuous variation method, we deduced that the stoichiometric ratios of the Prd/Mg2+ and Prd/Ca2+ complexes were 1:1 and 2:1, respectively. All of the evidence led us to conclude that the Prd/Mg2+ and Prd/Ca2+ complexes are mediated by different chelating mechanisms.
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Affiliation(s)
- Kathleen D Carillo
- International Graduate Program, SCST, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC; The Department of Applied Chemistry, National Chiao-Tung University, Hsinchu 30013, Taiwan, ROC; Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Danni Wu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Su-Ching Lin
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Shen-Long Tsai
- Chemical Engineering Department of NTUST, Taipei 10607, Taiwan, ROC
| | - Jiun-Jie Shie
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC; Department of Applied Chemistry, National Chia-Yi University, Chia-Yi 60004, Taiwan, ROC.
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Chang HW, Yang CH, Luo YC, Su BG, Cheng HY, Tung SY, Carillo KJD, Liao YT, Tzou DLM, Wang HC, Chang W. Vaccinia viral A26 protein is a fusion suppressor of mature virus and triggers membrane fusion through conformational change at low pH. PLoS Pathog 2019; 15:e1007826. [PMID: 31220181 PMCID: PMC6605681 DOI: 10.1371/journal.ppat.1007826] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/02/2019] [Accepted: 05/07/2019] [Indexed: 11/24/2022] Open
Abstract
Vaccinia mature virus requires A26 envelope protein to mediate acid-dependent endocytosis into HeLa cells in which we hypothesized that A26 protein functions as an acid-sensitive membrane fusion suppressor. Here, we provide evidence showing that N-terminal domain (aa1-75) of A26 protein is an acid-sensitive region that regulates membrane fusion. Crystal structure of A26 protein revealed that His48 and His53 are in close contact with Lys47, Arg57, His314 and Arg312, suggesting that at low pH these His-cation pairs could initiate conformational changes through protonation of His48 and His53 and subsequent electrostatic repulsion. All the A26 mutant mature viruses that interrupted His-cation pair interactions of His48 and His 53 indeed have lost virion infectivity. Isolation of revertant viruses revealed that second site mutations caused frame shifts and premature termination of A26 protein such that reverent viruses regained cell entry through plasma membrane fusion. Together, we conclude that viral A26 protein functions as an acid-sensitive fusion suppressor during vaccinia mature virus endocytosis. Vaccinia virus is a complex large DNA virus with a large number of viral membrane proteins to facilitate cell entry. Although it is well established that vaccinia mature virus uses endocytosis to enter cells, it remains unclear how it triggers membrane fusion in the acidic environment of endosomes. Recently, we hypothesized that A26 protein in vaccinia mature virus functions as an acid-sensitive membrane fusion suppressor, which suggests a novel viral regulation not present in other enveloped viruses. We postulated that conformational changes of A26 protein at low pH result in de-repression of viral fusion complex activity to trigger viral and endosomal membrane fusion. Here, we provide structural, biochemical and biological evidence demonstrating that vaccinia A26 protein does indeed function as an acid-sensitive fusion suppressor protein to regulate vaccinia mature virus membrane fusion during endocytosis. Our data reveal an important and unique “checkpoint” for vaccinia mature virus endocytosis that has not been described for other viruses. Furthermore, by isolating adaptive vaccinia mutants that escaped endocytic blockage, we discovered that mutations within the A26L gene serve as an effective strategy for switching the viral infection route from endocytosis to plasma membrane fusion, expanding viral host range.
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Affiliation(s)
- Hung-Wei Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Han Yang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Chun Luo
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Bo-Gang Su
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Huei-Yin Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Shu-Yun Tung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Kathleen Joyce D. Carillo
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
| | - Yi-Ting Liao
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taiwan
| | - Der-Lii M. Tzou
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Department of Applied Chemistry, National Chia-Yi University, Chia-Yi, Taiwan
| | - Hao-Ching Wang
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taiwan
- * E-mail: (HCW); (WC)
| | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- * E-mail: (HCW); (WC)
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Chang JY, Carollo KD, Lin SC, Wu YY, Tzou DLM. NMR investigation of magnesium chelation and cation-induced signal shift effect of testosterone. Steroids 2016; 115:18-25. [PMID: 27477887 DOI: 10.1016/j.steroids.2016.07.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/18/2016] [Accepted: 07/11/2016] [Indexed: 12/18/2022]
Abstract
We have previously reported that testosterone (Tes) is able to interact with magnesium chloride dissolved in methanol. In this study, we have applied 1H and 13C NMR spectroscopies to a series of Tes solutions containing Mg2+ at various concentrations. High-resolution 13C NMR spectra of Tes/Mg2+ revealed well-resolved 13C signals, and the intensities of those arising from C3, C5, C16, and C17 decreased linearly with increasing Mg2+ concentration. The magnitude of the chelation affinity could be deduced from the slopes of the 13C intensity variations; typically, the greater the slope the higher the chelation affinity. The results revealed Tes/Mg2+ chelation to be mediated by the oxygen atom attached to C3 in ring A, and the hydroxyl group attached to C17 in ring D. With regard to the chelation specificity, we showed that Tes chelates Mg2+, but not Ca2+ or Zn2+. We also explored the cation-induced signal shift effects of Tes in the presence of Mg2+, Ca2+, or Zn2+. We demonstrate that high-resolution 13C NMR spectroscopy provides a better probe than 1H NMR for the detection of cation chelation and cation-induced signal shift effects for steroid compounds such as Tes.
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Affiliation(s)
- Jen-Yu Chang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China
| | - Kathleen D Carollo
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China
| | - Su-Ching Lin
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China
| | - Ying-Yann Wu
- Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan, Republic of China
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China.
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Carillo KD, Arco S, Wang CC, Tzou DLM. Solid-state NMR investigation of effect of fluorination and methylation on prednisolone conformation. Steroids 2015; 104:263-9. [PMID: 26476185 DOI: 10.1016/j.steroids.2015.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 09/11/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
Abstract
Prednisolone (Prd) is a polymorphous synthetic corticosteroid that has three crystalline forms mediated by different solvents. In this study, we have demonstrated that solid-state {(1)H}(13)C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy is able to resolve the effects of methylation and fluorination on the conformation of the steroidal rings in Prd. Two compounds were chosen for the study, 6-α-methylprednisolone (Prd-6M) and 6-α-fluoroprednisolone (Prd-6F). The (13)C signals of Prd-6F showed primarily doublet patterns, with splittings of 40-380 Hz, indicating multiple ring conformations, whereas the (13)C signals of Prd and Prd-6M exhibited a singlet pattern, indicating a unique conformation. Using evidence from chemical shift deviation and anisotropy analysis, we have demonstrated by solid-state NMR that Prd-6F adopts two different steroidal ring conformations that are different from that of Prd-6M, and less similar to that of unsubstituted Prd.
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Affiliation(s)
- Kathleen D Carillo
- University of the Philippines Diliman, Diliman, Quezon City 1100, Philippines; Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Susan Arco
- University of the Philippines Diliman, Diliman, Quezon City 1100, Philippines
| | - Cheng-Chung Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.
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Wang D, Chen M, Chein RJ, Ching WM, Hung CH, Tzou DLM. Cation ion specifically induces a conformational change in trans-dehydroandrosterone - a solid-state NMR study. Steroids 2015; 96:73-80. [PMID: 25637678 DOI: 10.1016/j.steroids.2015.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 01/09/2015] [Accepted: 01/19/2015] [Indexed: 11/23/2022]
Abstract
In this work, we demonstrated that calcium (Ca(+2)) is able to induce a conformational change in trans-dehydroandrosterone (DHEA). To this respect, solid-state NMR spectroscopy was applied to a series of DHEA molecules that were incubated with Ca(+2) under different concentrations. The high-resolution (13)C NMR spectra of the DHEA/Ca(+2) mixtures exhibited two distinct sets of signals; one was attributed to DHEA in the free form, and the second set was due to the DHEA/Ca(+2) complex. Based on chemical shift isotropy and anisotropy analyses, we postulated that Ca(+2) might have associated with the oxygen attached to C17 via a lone-pair of electrons, which induced a conformational change in DHEA. Apart from Ca(+2), we also incubated DHEA with magnesium (Mg(+2)) to determine whether Mg(+2) was able to interact with DHEA in a similar manner to Ca(+2). We found that Mg(+2) was able to induce a conformational change in DHEA deviated from that of Ca(+2). These solid-state NMR observations indicate that DHEA is able to interact with cations, such as Mg(+2) and Ca(+2), with specificity.
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Affiliation(s)
- Darong Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Meiman Chen
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Rong-Jie Chein
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Wei-Min Ching
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Chen-Hsiung Hung
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.
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Wang YS, Ko CH, Chang HT, Yang KJ, Chen YJ, Huang SJ, Fang PJ, Chang CF, Tzou DLM. ¹H, ¹³C and ¹⁵N backbone and side-chain resonance assignments of a family 36 carbohydrate binding module of xylanase from Paenibacillus campinasensis. Biomol NMR Assign 2014; 8:303-306. [PMID: 23835623 DOI: 10.1007/s12104-013-9505-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/29/2013] [Indexed: 06/02/2023]
Abstract
Paenibacillus campinasensis BL11 isolated from black liquor secretes multiple glycoside hydrolases (GHs) against all kinds of polysaccharides. GH consists of a catalytic module and non-catalytic carbohydrate-binding modules (CBMs), in which CBMs append to the catalytic module, mediating specific interactions with insoluble carbohydrates to promote the hydrolysis efficiency of the cognate enzyme. Endo-β-1,4-xylanase (XylX) is one of the GHs reveals high enzymatic activity in a wide range of pH and thermal endurance, suitable for bioconversion and bio-refinement applications. In this work, we report the resonance assignments of a family 36 CBM (characterized as CBM36) derived from XylX. Our investigations will facilitate molecular structure determination and molecular dynamics analysis of CBMs.
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Affiliation(s)
- Yu-Sheng Wang
- School of Forestry and Resource Conservation, National Taiwan University, Taipei, Taiwan, ROC
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17
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Abstract
Solid-state {(1)H}(13)C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy was performed to analyze two fluorinated steroids, i.e., betamethasone (BMS) and fludrocortisone acetate (FCA), that have fluorine attached to C9, as well as two non-fluorinated analogs, i.e., prednisolone (PRD) and hydrocortisone 21-acetate (HCA). The (13)C signals of BMS revealed multiplet patterns with splittings of 16-215Hz, indicating multiple ring conformations, whereas the (13)C signals of FCA, HCA, and PRD exhibited only singlet patterns, implying a unique conformation. In addition, BMS and FCA exhibited substantial deviation (>3.5ppm) in approximately half of the (13)C signals and significant deviation (>45ppm) in the (13)C9 signal compared to PRD and HCA, respectively. In this study, we demonstrate that fluorinated steroids, such as BMS and FCA, have steroidal ring conformation(s) that are distinct from non-fluorinated analogs, such as PRD and HCA.
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Affiliation(s)
- Kai-Jay Yang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Su-Ching Lin
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei 11617, Taiwan, ROC
| | - Wei-Min Ching
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Chen-Hsiung Hung
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.
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Wang DR, Hsiao JC, Wong CH, Li GC, Lin SC, Yu SSF, Chen W, Chang W, Tzou DLM. Vaccinia viral protein A27 is anchored to the viral membrane via a cooperative interaction with viral membrane protein A17. J Biol Chem 2014; 289:6639-6655. [PMID: 24451374 DOI: 10.1074/jbc.m114.547372] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The vaccinia viral protein A27 in mature viruses specifically interacts with heparan sulfate for cell surface attachment. In addition, A27 associates with the viral membrane protein A17 to anchor to the viral membrane; however, the specific interaction between A27 and A17 remains largely unclear. To uncover the active binding sites and the underlying binding mechanism, we expressed and purified the N-terminal (18-50 residues) and C-terminal (162-203 residues) fragments of A17, which are denoted A17-N and A17-C. Through surface plasmon resonance, the binding affinity of A27/A17-N (KA = 3.40 × 10(8) m(-1)) was determined to be approximately 3 orders of magnitude stronger than that of A27/A17-C (KA = 3.40 × 10(5) m(-1)), indicating that A27 prefers to interact with A17-N rather than A17-C. Despite the disordered nature of A17-N, the A27-A17 interaction is mediated by a specific and cooperative binding mechanism that includes two active binding sites, namely (32)SFMPK(36) (denoted as F1 binding) and (20)LDKDLFTEEQ(29) (F2). Further analysis showed that F1 has stronger binding affinity and is more resistant to acidic conditions than is F2. Furthermore, A27 mutant proteins that retained partial activity to interact with the F1 and F2 sites of the A17 protein were packaged into mature virus particles at a reduced level, demonstrating that the F1/F2 interaction plays a critical role in vivo. Using these results in combination with site-directed mutagenesis data, we established a computer model to explain the specific A27-A17 binding mechanism.
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Affiliation(s)
- Da-Rong Wang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529
| | - Jye-Chian Hsiao
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 11529
| | - Chien-Hsuan Wong
- Department of Applied Chemistry, National Chia-Yi University, Chia-Yi, 60004, Taiwan, Republic of China
| | - Guo-Chian Li
- Department of Applied Chemistry, National Chia-Yi University, Chia-Yi, 60004, Taiwan, Republic of China
| | - Su-Ching Lin
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529
| | - Steve S-F Yu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529
| | - Wenlung Chen
- Department of Applied Chemistry, National Chia-Yi University, Chia-Yi, 60004, Taiwan, Republic of China
| | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 11529
| | - Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529.
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Tzou DLM, Ni LK, Chen MM, Chiou MC, Chen LC, Hsu ST, Ku KL, Cheng CC. Fingerprints of Phalaenopsis Tissues in Growth and Spike Induction Periods-A Solid-state 13C NMR Approach. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.201300099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tzou DLM. Bandwidth in double cross-polarization MAS NMR spectroscopy. Solid State Nucl Magn Reson 2012; 47-48:23-27. [PMID: 22925494 DOI: 10.1016/j.ssnmr.2012.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/05/2012] [Accepted: 08/06/2012] [Indexed: 06/01/2023]
Abstract
The signal intensity in double cross-polarization (DCP) NMR experiments is critically dependent on the experimental parameters, which include the rf field strength, carrier frequency, and magic-angle spinning (MAS) frequency. In this systematic study, we have monitored {(1)H}/(31)P/(13)C DCP signals from monosaccharide α-D-[UL-(13)C(6)] galactopyranosyl 1-phosphate (GalP) at a MAS frequency of 13 kHz, at which only double quantum cross-polarization (CP) coherence transfer is allowed. To lessen the stringent requirements for these experimental parameters, we have implemented linear ramp pulse, adiabatic ramp-shaped pulse, and block pulse during the period of (31)P/(13)C CP. We unravel the CP matching profiles with respect to these parameters by monitoring the (31)P/(13)C signal while varying the rf field strength and carrier frequency. For comparison, we extracted the selectivity bandwidth from the full width at half maximum (FWHM) of the matching profiles, in units of frequency (kHz), and found bandwidths of 1.1, 14, and 22 kHz for the matching profiles of the (13)C rf field strength and the (13)C and (31)P carrier frequencies, respectively, for a linear ramp pulse CP. These bandwidths are broader than the measured values in an adiabatic-shaped pulse CP (0.8, 10, and 12 kHz), as well as in block CP (0.3, 7, and 10 kHz) experiments. We demonstrate that the linear ramp pulse CP is superior to both block CP and adiabatic-shaped CP in lessening the stringent requirements of the aforementioned experimental settings for DCP experiments.
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Affiliation(s)
- Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC.
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Li GC, Wang DR, Chen W, Tzou DLM. Solid-state NMR analysis of steroidal conformation of 17α- and 17β-estradiol in the absence and presence of lipid environment. Steroids 2012; 77:185-92. [PMID: 22155023 DOI: 10.1016/j.steroids.2011.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 10/11/2011] [Accepted: 11/08/2011] [Indexed: 11/15/2022]
Abstract
Solid-state {(1)H}(13)C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy has been applied to 17β-estradiol (E2) and 17α-estradiol (E2α), to analyze the steroidal ring conformations of the two isomers in the absence and presence of lipids at the atomic level. In the absence of lipid, the high-resolution (13)C NMR signals of E2 in a powdered form show only singlet patterns, suggesting a single ring conformation. In contrast, the (13)C signals of E2α reveal multiplet patterns with splittings of 20-300Hz, implying multiple ring conformations. In the presence of a mimic of the lipid environment, made by mixing 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC) in a molar ratio 3:1, E2 and E2α revealed multiplet patterns different from those seen in the absence of lipids, indicating that the two isomers adopt multiple conformations in the lipid environment. In this work, on the basis of chemical shift isotropy and anisotropy analysis, we demonstrated that E2 and E2α prefer to adopt multiple steroidal ring conformations in the presence of a lipid environment, distinct from that observed in solution phase and powdered form.
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Affiliation(s)
- Guo-Chian Li
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
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Shih PC, Li GC, Yang KJ, Chen W, Tzou DLM. Conformational analysis of steroid hormone molecules in the lipid environment--a solid-state NMR approach. Steroids 2011; 76:558-63. [PMID: 21335019 DOI: 10.1016/j.steroids.2011.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Revised: 02/08/2011] [Accepted: 02/09/2011] [Indexed: 10/18/2022]
Abstract
Solid-state (1)H/(13)C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy has been applied to two steroid compounds: dehydroepiandrosterone (DHEA) and spironolactone (SPI), to analyze their conformations at the atomic level. In the absence of lipid, the high-resolution (13)C CP/MAS NMR signals of DHEA and SPI in a powder form reveal multiple patterns, with splittings of 30-160 Hz, indicating the existence of multiple conformations. In the mimic lipid environment formed by mixing 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-diheptanoyl-sn-glycero-3-phosphocholine (DHPC) in a molar ratio 3:1, the resulting DHEA and SPI spectra revealed mostly singlet patterns, suggesting that these steroids undergo a conformational change leading to a specific conformation in the lipid environment. Evidence from chemical shift isotropy and anisotropy analysis indicates that DHEA might adopt conformations subtly different from that seen in solution and in the powder form. In conclusion, we demonstrate by solid-state NMR that the structures of DHEA and SPI may adopt slightly different conformations in different chemical environments.
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Affiliation(s)
- Ping-Chen Shih
- Institute of Chemistry, Academia Sinica, 128, Yen-Chiu-Yuan Rd., Sec. 2, Nankang, Taipei 11529, Taiwan, ROC
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Shih PC, Yang MS, Lin SC, Ho Y, Hsiao JC, Wang DR, Yu SSF, Chang W, Tzou DLM. A turn-like structure "KKPE" segment mediates the specific binding of viral protein A27 to heparin and heparan sulfate on cell surfaces. J Biol Chem 2009; 284:36535-36546. [PMID: 19858217 DOI: 10.1074/jbc.m109.037267] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vaccinia viral envelope protein A27 (110 amino acids) specifically interacts with heparin (HP) or heparan sulfate (HS) proteoglycans for cell surface attachment. To examine the binding mechanism, a truncated soluble form of A27 (sA27-aa; residues 21-84 of A27) with Cys(71) and Cys(72) mutated to Ala was used as the parent molecule. sA27-aa consists of two structurally distinct domains, a flexible Arg/Lys-rich heparin-binding site (HBS) (residues 21-32; (21)STKAAKKPEAKR(32)) and a rigid coiled-coil domain (residues 43-84), both essential for the specific binding. As shown by surface plasmon resonance (SPR), the binding affinity of sA27-aa for HP (K(A) = 1.25 x 10(8) m(-1)) was approximately 3 orders of magnitude stronger than that for nonspecific binding, such as to chondroitin sulfate (K(A) = 1.65 x 10(5) m(-1)). Using site-directed mutagenesis of HBS and solution NMR, we identified a "KKPE" segment with a turn-like conformation that mediates specific HP binding. In addition, a double mutant T22K/A25K in which the KKPE segment remained intact showed an extremely high affinity for HP (K(A) = 1.9 x 10(11) m(-1)). Importantly, T22K/A25K retained the binding specificity for HP and HS but not chondroitin sulfate, as shown by in vitro SPR and in vivo cell adhesion and competitive binding assays. Molecular modeling of the HBS was performed by dynamics simulations and provides an explanation of the specific binding mechanism in good agreement with the site-directed mutagenesis and SPR results. We conclude that a turn-like structure introduced by the KKPE segment in vaccinia viral envelope protein A27 is responsible for its specific binding to HP and to HS on cell surfaces.
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Affiliation(s)
- Ping-Chen Shih
- Institutes of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Min-Shiang Yang
- Institutes of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Su-Ching Lin
- Institutes of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Yu Ho
- Institutes of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Jye-Chian Hsiao
- Institutes of Molecular Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Da-Rong Wang
- Department of Chemistry, Fu-Jen Catholic University, Taipei 242, Taiwan
| | - Steve S-F Yu
- Institutes of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Wen Chang
- Institutes of Molecular Biology, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Der-Lii M Tzou
- Institutes of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan; Department of Applied Chemistry, National Chia-Yi University, Chia-Yi 60004, Taiwan.
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Mousavi M, Yu SSF, Tzou DLM. A (13)C solid-state NMR analysis of vitamin D compounds. Solid State Nucl Magn Reson 2009; 36:24-31. [PMID: 19493660 DOI: 10.1016/j.ssnmr.2009.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 03/25/2009] [Accepted: 04/22/2009] [Indexed: 05/27/2023]
Abstract
(13)C cross-polarization/magic-angle spinning (CP/MAS) solid-state NMR spectroscopy has been employed to analyze four vitamin D compounds, namely vitamin D3 (D3), vitamin D2 (D2), and the precursors ergosterol (Erg) and 7-dehydrocholesterol (7DHC). The (13)C NMR spectrum of D3 displays a doublet pattern for each of the carbon atoms, while that of Erg contains both singlet and doublet patterns. In the cases of 7DHC and D2, the (13)C spectra display various multiplet patterns, viz. singlets, doublets, triplets, and quartets. To overcome the signal overlap between the (13)C resonances of protonated and unprotonated carbons, we have subjected these vitamin D compounds to 1D (1)H-filtered (13)C CP/MAS and {(1)H}/(13)C heteronuclear correlation (Hetcor) NMR experiments. As a result, assisted by solution NMR data, all of the (13)C resonances have been successfully assigned to the respective carbon atoms of these vitamin D compounds. The (13)C multiplets are interpreted due to the presence of s-cis and s-trans configurations in the alpha- and beta-molecular conformers, consistent with computer molecular modeling determined by molecular dynamics and energy minimization calculations. To further characterize the ring conformations in D3, we have successfully extracted chemical shift tensor elements for the (13)C doublets. It is demonstrated that (13)C solid-state NMR spectroscopy provides a robust and high sensitive means of characterizing molecular conformations in vitamin D compounds.
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Affiliation(s)
- Mansoureh Mousavi
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
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Yang JH, Chou FC, Tzou DLM. Coherence selection in double CP MAS NMR spectroscopy. J Magn Reson 2008; 195:116-120. [PMID: 18782675 DOI: 10.1016/j.jmr.2008.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 08/15/2008] [Accepted: 08/19/2008] [Indexed: 05/26/2023]
Abstract
Applications of double cross-polarization (CP) magic-angle spinning (MAS) NMR spectroscopy, via (1)H/(15)N and then (15)N/(13)C coherence transfers, for (13)C coherence selection are demonstrated on a (15)N/(13)C-labeled N-acetyl-glucosamine (GlcNAc) compound. The (15)N/(13)C coherence transfer is very sensitive to the settings of the experimental parameters. To resolve explicitly these parameter dependences, we have systematically monitored the (13)C{(15)N/(1)H} signal as a function of the rf field strength and the MAS frequency. The data reveal that the zero-quantum coherence transfer, with which the (13)C effective rf field is larger than that of the (15)N by the spinning frequency, would give better signal sensitivity. We demonstrate in one- and two-dimensional double CP experiments that spectral editing can be achieved by tailoring the experimental parameters, such as the rf field strengths and/or the MAS frequency.
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Affiliation(s)
- Jen-Hsien Yang
- Institute of Chemistry, Academia Sinica, 128, Yen-Chiu-Yuan Road, Sec. 2, Nankang, Taipei 11529, Taiwan, ROC
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Abstract
(13)C CP/MAS solid-state NMR spectroscopy has been utilized to analyze six steroid compounds, namely testosterone (Tes), hydrocortisone (Cor), trans-dehydroandrosterone (Adr), prednisolone (Prd), prednisone (Pre) and estradiol (Est). Among them, Tes displays a doublet pattern for all residues, whereas Prd, Pre and Est, exhibit exclusively singlets. For Cor and Adr, the (13)C spectra contain both doublet and singlet patterns. The (13)C doublet signal, with splittings of 0.2-1.5 ppm, are ascribed to local differences in the ring conformations associated with polymorphism. We have assigned all of the (13)C resonances to the different residues in these steroid compounds on the basis of solution NMR data. The C-7, C-8, C-10, C-15 and C-16 residues of Tes, Cor and Adr consistently give rise to singlets or doublets with splittings of less than 0.5 ppm, indicating similar local conformations. Accompanying hydration and dehydration processes, a reversible phase transformation between delta- and alpha-crystal forms has been observed in Tes, corresponding to singlet and doublet (13)C patterns, respectively. To further characterize the ring conformations in the alpha-form, we have successfully extracted chemical shift tensor elements for the (13)C doublets. It is demonstrated that (13)C solid-state NMR spectroscopy provides a reliable and sensitive means of characterizing polymorphism in steroids.
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Affiliation(s)
- Jen-Hsien Yang
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
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Chu FI, Ho Y, Huang CJ, Tzou DLM. 1H, 13C and 15N resonance assignments for proapoptotic protein Nix (residue 1 approximately 156) from Danio rerio. Biomol NMR Assign 2007; 1:29-31. [PMID: 19636819 DOI: 10.1007/s12104-007-9006-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Accepted: 01/24/2007] [Indexed: 05/28/2023]
Abstract
Nix protein is a BH3-only pro-apoptotic mitochondrial protein. Here we reported the 1H, 13C and 15N resonance assignments of zebrafish Nix protein for further understanding the structure and function relationship.
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Affiliation(s)
- Feng-I Chu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
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Chang CW, Chen YN, Adak AK, Lin KH, Tzou DLM, Lin CC. Synthesis of phytosphingosine using olefin cross-metathesis: a convenient access to chain-modified phytosphingosines from d-lyxose. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.03.047] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Chiu WL, Lin CL, Yang MH, Tzou DLM, Chang W. Vaccinia virus 4c (A26L) protein on intracellular mature virus binds to the extracellular cellular matrix laminin. J Virol 2007; 81:2149-57. [PMID: 17166913 PMCID: PMC1865921 DOI: 10.1128/jvi.02302-06] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 12/01/2006] [Indexed: 01/16/2023] Open
Abstract
Vaccinia virus intracellular mature virus (IMV) binds to glycosaminoglycans (GAGs) on cells via three virion proteins, H3L, A27L, and D8L. In this study, we demonstrated that binding of IMV to BSC40 cells was competitively inhibited by soluble laminin but not by fibronectin or collagen V, suggesting that this cell surface extracellular matrix (ECM) protein may play a role in vaccinia virus entry. Moreover, IMV infection of GAG(-) sog9 cells was also inhibited by laminin, demonstrating that virion binding to laminin does not involve a prior interaction with GAGs. Furthermore, comparative envelope protein analyses of wild-type vaccinia virus strain Western Reserve, which binds to laminin, and of a mutant virus, IA27L, which does not, showed that the A26L open reading frame (ORF), encoding an envelope protein, was mutated in IA27L, resulting in A26L being absent from the IMV. Expression of the wild-type A26L ORF in IA27L resulted in laminin binding activity. Moreover, recombinant A26L protein bound to laminin in vitro with a high affinity, providing direct evidence that A26L is the laminin binding protein on IMV. In summary, these results reveal a novel role for the vaccinia viral envelope protein A26L in binding to the ECM protein laminin, an association that is proposed to facilitate IMV entry.
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Affiliation(s)
- Wen-Ling Chiu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China.
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Ho Y, Tzou DLM, Chu FI. Solid-state NMR studies of the molecular structure of Taxol. Magn Reson Chem 2006; 44:581-5. [PMID: 16508916 DOI: 10.1002/mrc.1789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Solid-state 13C{1H} cross-polarization/magic angle spinning spectroscopy (CP/MAS) has been utilized to extract the molecular structure information of Taxol, which is an anti-tumor therapeutic medicine extracted from the yew bark. The 13C signals have chemical shift values quite consistent with those measured in solution phase, and the overall chemical shift range is over 200 ppm. Notably, most of the 13C resonances of the taxane ring have two clearly resolved spectral components except the resonance peaks of C-15, C-16 and C-17, which are located at the central part of the taxane ring. On the basis of our NMR data, we propose that these doublets originate from two slightly different molecular conformations of the taxane ring and still the central part of the ring remains structurally similar. Furthermore, it is demonstrated that the 13C chemical shift difference deduced from the doublet splittings can serve as a direct measure of the structural difference between the two conformations, which could possibly correlate with the anti-tumor activity of Taxol.
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Affiliation(s)
- Yu Ho
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China
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Ho Y, Hsiao JC, Yang MH, Chung CS, Peng YC, Lin TH, Chang W, Tzou DLM. The oligomeric structure of vaccinia viral envelope protein A27L is essential for binding to heparin and heparan sulfates on cell surfaces: a structural and functional approach using site-specific mutagenesis. J Mol Biol 2005; 349:1060-71. [PMID: 15913650 DOI: 10.1016/j.jmb.2005.04.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 04/08/2005] [Accepted: 04/13/2005] [Indexed: 11/21/2022]
Abstract
The soluble domain of the self-assembly vaccinia virus envelope protein A27L, sA27L-aa, consists of a flexible extended coil at the N terminus and a rigid hydrophobic coiled-coil region at the C terminus. In the former, a basic strip of 12 residues is responsible for binding to cell-surface heparan sulfates. Although the latter is believed to mediate self-assembly, its biological role is unclear. However, an in vitro bioassay showed that peptides comprising the 12 residue basic region alone failed to interact with heparin, suggesting that the C-terminal coiled-coil region might serve an indispensable role in biological function. To explore this structural and functional relationship, we performed site-specific mutagenesis in an attempt to specifically disrupt the hydrophobic core of the coiled coil. Three single mutants, L47A, L51A, and L54A, and one triple mutant, L47,51,54A, were expressed and purified from Escherichia coli. The physical properties of the mutants were carefully examined by gel-filtration chromatography, CD, and NMR spectroscopy, and the biological activities were assessed by an in vitro SPR bioassay and three in vivo bioassays: binding to cells, blocking virus infection and blocking cell fusion. We showed that the L47A mutant, which is similar to the parental sA27L-aa in forming a hexamer, is biologically active. L51A and L54A mutants form tetramers and are less active. Notably, in the triple mutant, the self-assembly hydrophobic core structure is uncoiled; as a consequence, the tetrameric structure is biologically inactive. Thus, we conclude that the leucine residues, in particular Leu51 and Leu54, sustain the hydrophobic core structure that is essential for the biological function of vaccinia virus envelope protein A27L, binding to cell-surface heparan sulfate.
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Affiliation(s)
- Yu Ho
- Institute of Chemistry, Academia Sinica, 128 Yen-Chiu-Yuan Rd., Sec. 2, Nankang, Taipei 11529, Taiwan, R.O.C
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Tzou DLM. A solid-state NMR application of the anomeric effect in carbohydrates: galactosamine, glucosamine, and N-acetyl-glucosamine. Solid State Nucl Magn Reson 2005; 27:209-214. [PMID: 15799877 DOI: 10.1016/j.ssnmr.2004.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Revised: 11/15/2004] [Indexed: 05/24/2023]
Abstract
Simple 2D 13C/15N heteronuclear correlation solid-state NMR spectroscopy was implemented to resolve the 15N resonances of the alpha and beta anomers of three amino monosaccharides: galactosamine (GalN), glucosamine hydrochloride (GlcN), and N-acetyl-glucosamine (GlcNAc) labeled specifically with 13C1/15N spin pairs. Although the 15N resonances could not be distinguished in normal 1D spectra, they were well resolved in 2D double CP/MAS correlation spectra by taking advantage of the 13C spectral resolution. The alpha and beta resonances shifted apart by 3-5 ppm in their 13C chemical shifts, and differed by 1-2 ppm in the extended 15N dimension. Aside from this, the detection of other 13C/15N correlations over short distances was also achieved arising from the C2, C3 and CO carbons present in natural abundance. 2D double CP/MAS chemical shift correlation NMR spectroscopy is a simple and powerful technique to characterize the anomeric effect of amino monosaccharides. Applications of the 2D method reveal well-resolved 15N and 13C chemical shifts might be useful for structural determination on carbohydrates of biological significance, such as glycopeptide or glycolipids.
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Affiliation(s)
- Der-Lii M Tzou
- Institute of Chemistry, Academia Sinica, Nankang, Number 128, Yen-Chiu-Yuan Road, Taipei 11529, Taiwan, ROC.
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Chu FI, Ho Y, Tzou DLM. NMR assignment of the vaccinia virus envelope protein A27L. J Biomol NMR 2005; 32:178. [PMID: 16034674 DOI: 10.1007/s10858-005-7061-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Revised: 04/07/2005] [Accepted: 04/15/2005] [Indexed: 05/03/2023]
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Chen YY, Luo SY, Hung SC, Chan SI, Tzou DLM. 13C Solid-state NMR chemical shift anisotropy analysis of the anomeric carbon in carbohydrates. Carbohydr Res 2005; 340:723-9. [PMID: 15721345 DOI: 10.1016/j.carres.2005.01.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Accepted: 01/16/2005] [Indexed: 11/25/2022]
Abstract
(13)C NMR solid-state structural analysis of the anomeric center in carbohydrates was performed on six monosaccharides: glucose (Glc), mannose (Man), galactose (Gal), galactosamine hydrochloride (GalN), glucosamine hydrochloride (GlcN), and N-acetyl-glucosamine (GlcNAc). In the 1D (13)C cross-polarization/magic-angle spinning (CP/MAS) spectrum, the anomeric center C-1 of these carbohydrates revealed two well resolved resonances shifted by 3-5ppm, which were readily assigned to the anomeric alpha and beta forms. From this experiment, we also extracted the (13)C chemical shift anisotropy (CSA) tensor elements of the two forms from their spinning sideband intensities, respectively. It was found out that the chemical shift tensor for the alpha anomer was more axially symmetrical than that of the beta form. A strong linear correlation was obtained when the ratio of the axial asymmetry of the (13)C chemical shift tensors of the two anomeric forms was plotted in a semilogarithmic plot against the relative population of the two anomers. Finally, we applied REDOR spectroscopy to discern whether or not there were any differences in the sugar ring conformation between the anomers. Identical two-bond distances of 2.57A (2.48A) were deduced for both the alpha and beta forms in GlcNAc (GlcN), suggesting that the two anomers have essentially identical sugar ring scaffolds in these sugars. In light of these REDOR distance measurements and the strong correlation observed between the ratio of the axial asymmetry parameters of the (13)C chemical shift tensors and the relative population between the two anomeric forms, we concluded that the anomeric effect arises principally from interaction of the electron charge clouds between the C-1-O-5 and the C-1-O-1 bonds in these monosaccharides.
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Affiliation(s)
- Ying-Ying Chen
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 11529, Taiwan, ROC
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Lin CC, Pan YS, Patkar LN, Lin HM, Tzou DLM, Subramanian T, Lin CC. Versatile approach for the synthesis of novel seven-membered iminocyclitols via ring-closing metathesis dihydroxylation reaction. Bioorg Med Chem 2005; 12:3259-67. [PMID: 15158794 DOI: 10.1016/j.bmc.2004.03.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Revised: 03/29/2004] [Accepted: 03/30/2004] [Indexed: 11/22/2022]
Abstract
Seven-membered iminocyclitols with diverse diastereomers were prepared starting with d- and l-serines and employing ring-closing olefin metathesis and dihydroxylation reaction sequence. The iminocyclitols were assayed for glycosidase inhibition and compound 20 was found to be a competitive inhibitor for beta-glucosidase with Ki 26.3 microM.
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Affiliation(s)
- Chang-Ching Lin
- Department of Chemistry, Tsing Hua University, Hsinchu 300, Taiwan.
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Abstract
In the present study, an efficient method with a high overall yield for preparing phytosphingosine and an analogue was developed. Starting with commercially available 2,3;5,6-di-O-isopropylidene-d-mannofuranose, a variety of lipid moieties were incorporated to obtain phytosphingosine and an analogue. Through an eight-step manipulation, phytosphingosine was obtained with an overall yield of 57%.
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Affiliation(s)
- Hsin-Yi Chiu
- Institute of Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
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Lin TH, Chia CM, Hsiao JC, Chang W, Ku CC, Hung SC, Tzou DLM. Structural analysis of the extracellular domain of vaccinia virus envelope protein, A27L, by NMR and CD spectroscopy. J Biol Chem 2002; 277:20949-59. [PMID: 11901147 DOI: 10.1074/jbc.m110403200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study presents the molecular structure of the extracellular domain of vaccinia virus envelope protein, A27L, determined by NMR and CD spectroscopy. A recombinant protein, eA27L-aa, containing this domain in which cysteines 71 and 72 were replaced with alanine, was constructed to prevent self-assembly due to intermolecular disulfide bonds between these two cysteines. The soluble eA27L-aa protein forms an oligomer resembling that of A27L on vaccinia virions. Heteronuclear correlation NMR spectroscopy was carried out on eA27L-aa in the presence or absence of urea to determine backbone resonance assignments. Chemical shift index (CSI) propensity analysis showed that eA27L-aa has two distinct structural domains, a relatively flexible 22-amino acid random coil in the N-terminal region and a fairly rigid alpha-helix structure in the remainder of the structure. Binding interaction studies using isothermal titration calorimetry suggest that a 12-amino acid lysine/arginine-rich segment in the N-terminal region is responsible for glycosaminoglycan binding. The rigid alpha-helix portion of eA27L-aa is probably involved in the intrinsic self-assembly, and CSI propensity analysis suggests that region N37-E49, with a residual alpha-helix tendency, is probably the self-assembly core. Self-assembly was ascribed to three hydrophobic leucine residues (Leu(41), Leu(45), and Leu(48)) in this segment. The folding mechanism of eA27L-aa was analyzed by CD spectroscopy, which revealed a two-step transition with a Gibbs free energy of 2.5 kcal/mol in the absence of urea. Based on these NMR and CD studies, a residue-specific molecular model of the extracellular domain of A27L is proposed. These studies on the molecular structure of eA27L-aa will help in understanding how vaccinia virus enters cells.
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Affiliation(s)
- Ta-Hsien Lin
- Institute of Biochemistry, National Yang-Ming University, Shih-pai, Taipei 11221, Taiwan
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