1
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Feng RR, Wang M, Zhang W, Gai F. Unnatural Amino Acids for Biological Spectroscopy and Microscopy. Chem Rev 2024; 124:6501-6542. [PMID: 38722769 DOI: 10.1021/acs.chemrev.3c00944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Abstract
Due to advances in methods for site-specific incorporation of unnatural amino acids (UAAs) into proteins, a large number of UAAs with tailored chemical and/or physical properties have been developed and used in a wide array of biological applications. In particular, UAAs with specific spectroscopic characteristics can be used as external reporters to produce additional signals, hence increasing the information content obtainable in protein spectroscopic and/or imaging measurements. In this Review, we summarize the progress in the past two decades in the development of such UAAs and their applications in biological spectroscopy and microscopy, with a focus on UAAs that can be used as site-specific vibrational, fluorescence, electron paramagnetic resonance (EPR), or nuclear magnetic resonance (NMR) probes. Wherever applicable, we also discuss future directions.
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Affiliation(s)
- Ran-Ran Feng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Manxi Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wenkai Zhang
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China
| | - Feng Gai
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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2
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Baweja S, Kalal B, Maity S. Spectroscopic Characterization of Hydrogen-Bonded 2,7-Diazaindole Water Complex Isolated in the Gas Phase. J Phys Chem A 2024; 128:3329-3338. [PMID: 38652167 DOI: 10.1021/acs.jpca.4c01113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
We present a systematic experimental analysis of the 1:1 complex of 2,7-diazaindole (27DAI) with water in the gas phase. The complex was characterized by using two-color-resonant two-photon ionization (R2PI), laser-induced fluorescence (LIF), single vibronic level fluorescence (SVLF), and photoionization efficiency (PIE) spectroscopic methods. The 000 band of the S1←S0 electronic transition of the 27DAI-H2O complex was observed at 33,074 cm-1, largely red-shifted by 836 cm-1 compared to that of the bare 27DAI. From the R2PI spectrum, the detected modes at 141 (ν'Tx), 169 (ν'Ty), and 194 (ν'Ry) cm-1 were identified as the internal motions of the H2O molecule in the complex. However, these modes were detected at 115 (ν″Tx), 152 (ν″Ty), and 190 (ν″Ry) cm-1 in the ground state, which suggested a stronger hydrogen bonding interaction in the photo-excited state. The structural determination was aided by the detection of νNH and νOH values in the ground and excited state complexes using the FDIR and IDIR spectroscopies. The detection of νNH at 3414 and νOH at 3447 cm-1 in 27DAI-H2O has shown an excellent correlation with the most stable structure consisting of N(1)-H···O and OH···N(7) hydrogen-bonded bridging water molecule in the ground state. The structure of the complex in the electronic excited state (S1) was confirmed by the corresponding bands at 3210 (νNH) and 3265 cm-1 (νOH). The IR-UV hole-burning spectroscopy confirmed the presence of only one isomer in the molecular beam. The ionization energy (IE) of the 27DAI-H2O complex was obtained as 8.789 ± 0.002 eV, which was significantly higher than the 7AI-H2O complex. The higher IE values of N-rich molecules suggest a higher resistivity of such molecules against photodamage. The obtained structure of the 27DAI-H2O complex has explicitly shown the formation of a cyclic one-solvent bridge incorporating N(1)-H···O and O-H···N(7) hydrogen bonds upon microsolvation. The lower excitation and higher ionization energies of the 27DAI-H2O complex compared to 7AI-H2O established higher stabilization of N-rich molecules. The solvent clusters forming a linear bridge between the hydrogen/proton acceptor and donor sites in the complex can be considered as a stepping stone to investigate the photoinduced deactivation mechanisms in nitrogen containing biologically relevant molecules.
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Affiliation(s)
- Simran Baweja
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana 502284, India
| | - Bhavika Kalal
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana 502284, India
| | - Surajit Maity
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana 502284, India
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3
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Richaud AD, Mandal S, Das A, Roche SP. Tunable CH/π Interactions within a Tryptophan Zipper Motif to Stabilize the Fold of Long β-Hairpin Peptides. ACS Chem Biol 2023; 18:2555-2563. [PMID: 37976523 DOI: 10.1021/acschembio.3c00553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The tryptophan zipper (Trpzip) is an iconic folding motif of β-hairpin peptides capitalizing on two pairs of cross-strand tryptophans, each stabilized by an aromatic-aromatic stacking in an edge-to-face (EtF) geometry. Yet, the origins and the contribution of this EtF packing to the unique Trpzip stability remain poorly understood. To address this question of structure-stability relationship, a library of Trpzip hairpins was developed by incorporating readily accessible nonproteinogenic tryptophans of varying electron densities. We found that each EtF geometry was, in fact, stabilized by an intricate combination of XH/π interactions. By tuning the π-electron density of Trpface rings, CH/π interactions are strengthened to gain additional stability. On the contrary, our DFT calculations support the notion that Trpedge modulations are challenging due to their simultaneous paradoxical engagement as H-bond donors in CH/π and acceptors in NH/π interactions.
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Affiliation(s)
- Alexis D Richaud
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Sourav Mandal
- Department of Chemistry, Indian Institute of Science Education and Research Pune, Pashan, Pune 411008, India
| | - Aloke Das
- Department of Chemistry, Indian Institute of Science Education and Research Pune, Pashan, Pune 411008, India
| | - Stéphane P Roche
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
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4
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Gardner ED, Johnson BP, Dimas DA, McClurg HE, Severance ZC, Burgett AW, Singh S. Unlocking New Prenylation Modes: Azaindoles as a New Substrate Class for Indole Prenyltransferases. ChemCatChem 2023; 15:e202300650. [PMID: 37954549 PMCID: PMC10634513 DOI: 10.1002/cctc.202300650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Indexed: 11/14/2023]
Abstract
Aza-substitution, the replacement of aromatic CH groups with nitrogen atoms, is an established medicinal chemistry strategy for increasing solubility, but current methods of accessing functionalized azaindoles are limited. In this work, indole-alkylating aromatic prenyltransferases (PTs) were explored as a strategy to directly functionalize azaindole-substituted analogs of natural products. For this, a series of aza-l-tryptophans (Aza-Trp) featuring N-substitution of every aromatic CH position of the indole ring and their corresponding cyclic Aza-l-Trp-l-proline dipeptides (Aza-CyWP), were synthesized as substrate mimetics for the indole-alkylating PTs FgaPT2, CdpNPT, and FtmPT1. We then demonstrated most of these substrate analogs were accepted by a PT, and the regioselectivity of each prenylation was heavily influenced by the position of the N-substitution. Remarkably, FgaPT2 was found to produce cationic N-prenylpyridinium products, representing not only a new substrate class for indole PTs but also a previously unobserved prenylation mode. The discovery that nitrogenous indole bioisosteres can be accepted by PTs thus provides access to previously unavailable chemical space in the search for bioactive indolediketopiperazine analogs.
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Affiliation(s)
- Eric D. Gardner
- Department of Chemistry and Biochemistry, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, Oklahoma 73019, United States
| | - Bryce P. Johnson
- Department of Chemistry and Biochemistry, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, Oklahoma 73019, United States
| | - Dustin A. Dimas
- Department of Chemistry and Biochemistry, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, Oklahoma 73019, United States
| | - Heather E. McClurg
- Department of Chemistry and Biochemistry, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, Oklahoma 73019, United States
| | - Zachary C. Severance
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73117, United States
| | - Anthony W. Burgett
- Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73117, United States
| | - Shanteri Singh
- Department of Chemistry and Biochemistry, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, Oklahoma 73019, United States
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5
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Baweja S, Kalal B, Kumar Mitra P, Maity S. Competing Excited-State Hydrogen and Proton-Transfer Processes in 6-Azaindole-S 3,4 and 2,6-Diazaindole-S 3,4 Clusters (S=H 2 O, NH 3 ). Chemphyschem 2023:e202300270. [PMID: 37671972 DOI: 10.1002/cphc.202300270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/07/2023]
Abstract
Excited state hydrogen (ESHT) and proton (ESPT) transfer reaction pathways in the three and four solvent clusters of 6-azaindole (6AI-S3,4 ) and 2,6-diazaindole (26DAI-S3,4 )(S=H2 O, NH3 ) were computationally investigated to understand the fate of photo-excited biomolecules. The ESHT energy barriers in (H2 O)3 complexes (39.6-41.3 kJmol-1 ) were decreased in (H2 O)4 complexes (23.1-20.2 kJmol-1 ). Lengthening the solvent chain lowered the barrier because of the relaxed transition states geometries with reduced angular strains. Replacing the water molecule with ammonia drastically decreased the energy barriers to 21.4-21.3 kJmol-1 in (NH3 )3 complexes and 8.1-9.5 kJ mol-1 in (NH3 )4 complexes. The transition states were identified as Ha atom attached to the first solvent molecule. The formation of stronger hydrogen bonds in (NH3 )3,4 complexes resulted in facile ESHT reaction than that in the (H2 O)3,4 complexes. The ESPT energy barriers in 6AI-S3,4 and 26DAI-S3,4 were found to range between 40-73 kJmol-1 . The above values were significantly higher than that of the ESHT processes and hence are considered as a minor channel in the process. The effect of N(2) insertion was explored for the very first time in the isolated solvent clusters using local vibrational mode analysis. In DAI-S4 , the higher Ka (Ha ⋯Sa ) values depicted the increased photoacidity of the N(1)-Ha group which may facilitate the hydrogen transfer reaction. However, the increased N(6)⋯Hb bond length elevated the reaction barriers. Therefore, in the ESHT reaction channel, the co-existence of two competing factors led to a marginal/no change in the overall energy barriers due to the N(2) insertion. In the ESPT reaction pathway, the energy barriers showed notable increase upon N(2) insertion because of the increased N(6)⋯Hb bond length.
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Affiliation(s)
- Simran Baweja
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502284, India
| | - Bhavika Kalal
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502284, India
| | - Prajoy Kumar Mitra
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502284, India
| | - Surajit Maity
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502284, India
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6
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Demchenko AP. Proton transfer reactions: from photochemistry to biochemistry and bioenergetics. BBA ADVANCES 2023. [DOI: 10.1016/j.bbadva.2023.100085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
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7
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Roy Chowdhury P, Khodia S, Maity S. Solvent assisted excited-state deactivation pathways in isolated 2,7-diazaindole-S 1-3 (S = Water and Ammonia) complexes. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 278:121285. [PMID: 35533603 DOI: 10.1016/j.saa.2022.121285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 04/13/2022] [Accepted: 04/16/2022] [Indexed: 06/14/2023]
Abstract
The role of solvent molecules in the deactivation of photo-excited 2,7-diazaindole (DAI) - (H2O)1-3 and DAI - (NH3)1-3 complexes were computationally investigated. An excited-state proton transfer (ESPT) path from the solvent to the DAI molecule was followed using the TD-DFT-D4 (B3LYP) level of theory. The computed potential energy profile of ESPT process has shown intersection between ππ* and nπ* states facilitated via relative stabilization of the nπ* state with decreasing N(7)-Hb bond length. The ESPT process, starting from the DAI-Sn (ππ*) state, crosses through a barrier ranging from 27 to 36 kJmol-1 for water complexes and 26-30 kJmol-1 for ammonia complexes. The energy of the excited state was rapidly decreased with a shorter N(7)-Hb bond length. Subsequently, a significant trend of finding a second intersection between the ground and the excited state was observed for all the complexes. The results firmly suggested a significant deactivation channel of excited azaindole derivatives. In the present system, two competing channels, ESPT and ESHT, were found to be energetically accessible. The energy barriers associated with the ESPT barriers for DAI-(H2O)1-3 complexes are similar to the ESHT barrier, depicting equal dominance of both processes. The increased basicity of the N(7) atom in the excited state resulted a facile ESPT process from the water to N(7) of the DAI molecule. However, DAI-(NH3)1-3 complexes show clear preference for ESHT over ESPT process owing to its higher gas-phase pKa value making it a poor proton donor. The above systems can be used as a model to computationally and experimentally investigate the competing radiative and deactivation pathways of photo-excited solvated complexes of N-H-bearing bio-relevant molecules via proton and hydrogen transfer reactions.
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Affiliation(s)
| | - Saurabh Khodia
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana 502285, India
| | - Surajit Maity
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana 502285, India.
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8
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Zhu H, Ma P, Qian Y, Xia J, Gong F, Chen L, Xu L. Spectral Properties Echoing the Tautomerism of Milrinone and Its Application to Fe 3+ Ion Sensing and Protein Staining. BIOSENSORS 2022; 12:777. [PMID: 36290915 PMCID: PMC9599543 DOI: 10.3390/bios12100777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/16/2022] [Accepted: 09/18/2022] [Indexed: 06/16/2023]
Abstract
Knowledge on the spectral properties of the tautomers of milrinone (MLR) in solvents and solid-state, as well as under light conditions is of critical importance from both theoretical and practical points of view. Herein, we investigated the spectral properties of MLR in different conditions using UV-Vis and fluorescence spectroscopies. The experimental results demonstrated that MLR can undergo the tautomerization reaction induced by solvent polarity, light and pH, eliciting four tautomeric structures (enol, keto, anion, and cation forms). The interesting multi-functional groups in MLR enable it to coordinate with metal ions or to recognize gust molecules by H-bonding. In the use of MLR as an excited-state intermolecular proton transfer (inter-ESPT) fluorescent probe, a highly sensitive and selective analysis of Fe3+ was developed, which offered a sensitive detection of Fe3+ with the detection limit of 3.5 nM. More importantly, MLR exhibited the ability of anchoring proteins and led to the recognition-driven turn-on inter-ESPT process, highlighting the potential for the probe to image proteins in electrophoresis gels. The spectral experimental results revealed the possible degradation mechanism, so that we can better understand the side effects of oral preparations. The use of the available drug as an inter-ESPT fluorescent probe is simple and accurate, providing a good method for Fe3+ ion sensing and protein staining.
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9
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Yang WY, Yan CC, Wang XD, Liao LS. Recent progress on the excited-state multiple proton transfer process in organic molecules. Sci China Chem 2022. [DOI: 10.1007/s11426-022-1375-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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10
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Weigl P, Weißheit S, Pabst F, Kolmar H, Thiele CM, Walther T, Blochowicz T. Triplet States Reveal Slow Local Dynamics in the Solvation Shell of Biomolecules. J Phys Chem B 2022; 126:6324-6330. [PMID: 35973008 DOI: 10.1021/acs.jpcb.2c03784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein hydration shell dynamics plays a pivotal role in biochemical processes such as protein folding, enzyme function, molecular recognition and interaction with biological membranes. Thus, it is crucial to understand the mobility of the solvation shell at the surface of biomolecules. Triplet state solvation dynamics can reveal the slow dynamics of the solvation shell. This is done in the present work without adding separate dye molecules but instead by using a phosphorescent subgroup of the biomolecule itself. In particular, we study a small heptapeptide in a glycerol-water mixture under cryoconservation conditions so that the system can be supercooled without crystallization. We find a significant slowing of molecules in the solvation shell in the millisecond range compared to the bulk. This opens up the possibility to unravel the nature of relaxation processes in the solvation shell usually overlapping at room temperature.
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Affiliation(s)
- Peter Weigl
- Institute for Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany.,Institute for Applied Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Susann Weißheit
- Clemens-Schöpf-Institute for Organic Chemistry and Biochemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Florian Pabst
- Institute for Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Harald Kolmar
- Clemens-Schöpf-Institute for Organic Chemistry and Biochemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Christina Marie Thiele
- Clemens-Schöpf-Institute for Organic Chemistry and Biochemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Thomas Walther
- Institute for Applied Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Thomas Blochowicz
- Institute for Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
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11
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Urvashi, Senthil Kumar JB, Das P, Tandon V. Development of Azaindole-Based Frameworks as Potential Antiviral Agents and Their Future Perspectives. J Med Chem 2022; 65:6454-6495. [PMID: 35477274 PMCID: PMC9063994 DOI: 10.1021/acs.jmedchem.2c00444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Indexed: 11/29/2022]
Abstract
The azaindole (AI) framework continues to play a significant role in the design of new antiviral agents. Modulating the position and isosteric replacement of the nitrogen atom of AI analogs notably influences the intrinsic physicochemical properties of lead compounds. The intra- and intermolecular interactions of AI derivatives with host receptors or viral proteins can also be fine tuned by carefully placing the nitrogen atom in the heterocyclic core. This wide-ranging perspective article focuses on AIs that have considerable utility in drug discovery programs against RNA viruses. The inhibition of influenza A, human immunodeficiency, respiratory syncytial, neurotropic alpha, dengue, ebola, and hepatitis C viruses by AI analogs is extensively reviewed to assess their plausible future potential in antiviral drug discovery. The binding interaction of AIs with the target protein is examined to derive a structural basis for designing new antiviral agents.
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Affiliation(s)
- Urvashi
- Drug Discovery Laboratory, Special Centre for
Molecular Medicine, Jawaharlal Nehru University, New Delhi 110
067, India
- Department of Chemistry, University of
Delhi, New Delhi 110007, India
| | - J. B. Senthil Kumar
- Drug Discovery Laboratory, Special Centre for
Molecular Medicine, Jawaharlal Nehru University, New Delhi 110
067, India
| | - Parthasarathi Das
- Department of Chemistry, Indian Institute
of Technology (ISM), Dhanbad 826004, India
| | - Vibha Tandon
- Drug Discovery Laboratory, Special Centre for
Molecular Medicine, Jawaharlal Nehru University, New Delhi 110
067, India
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12
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Khodia S, Maity S. A combined experimental and computational study on the deactivation of a photo-excited 2,2'-pyridylbenzimidazole-water complex via excited-state proton transfer. Phys Chem Chem Phys 2022; 24:12043-12051. [PMID: 35537136 DOI: 10.1039/d2cp01121b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this report, we present solvent assisted excited-state proton transfer coupled to the deactivation of a photo-excited 2,2'-pyridylbenzimidazole bound to a single water molecule. Experimentally, the mass-selected 1 : 1 complex was probed using two-colour resonant two-photon ionization (2C-R2PI) and UV-UV hole-burning (HB) spectroscopy in a supersonically jet-cooled molecular beam. Computationally, three structural isomers were identified as the normal, the tautomer and the proton transfer product of the PBI-H2O complex in the excited S1 state using B3LYP-D4/def2-TZVPP and ADC(2) (MP2)/cc-pVDZ levels of theory. The most stable form in the ground state, i.e., the normal form, was identified using the excitation spectrum in the 30 544 to 30 936 cm-1 region. The 2C-R2PI spectrum showed a sudden break-off above the 000 + 392 cm-1 region, even though the Frack-Condon activity of the S1 ← S0 transition was measured beyond 000 + 1000 cm-1 in the HB spectrum. The intensity of the bands associated with the excited state intermolecular vibrational modes near the break-off region was found to be drastically decreased, which indicates efficient quantum mechanical tunnelling along the hydrogen transfer coordinate. The sudden disappearance of the intermolecular vibrational modes in the spectrum revealed the existence of a deactivation channel in the PBI-H2O complex near 392-450 cm-1 above the 000 transition. The computational investigation predicted that the deactivation of the excited-state occurred via the intersection between the S1 and S0 states, which was associated with the proton transfer from the H2O to the PBI molecule along the O(3)-H(4)→N(5) coordinate. The highest energy structure was identified as the point of intersection between the nπ* (S2) and ππ* (S1) states. The associated barrier height was experimentally determined to be 392-450 cm-1, which showed a reasonable agreement with the calculated excited-state proton transfer barrier. Competing reaction channels such as dissociation and tautomerization were found to be highly energetically inaccessible.
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Affiliation(s)
- Saurabh Khodia
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana, India.
| | - Surajit Maity
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana, India.
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13
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Liang Y, Luo J, Yang C, Guo S, Zhang B, Chen F, Su K, Zhang Y, Dong Y, Wang Z, Fu H, Sui G, Wang P. Directed evolution of the PobR allosteric transcription factor to generate a biosensor for 4-hydroxymandelic acid. World J Microbiol Biotechnol 2022; 38:104. [PMID: 35501522 DOI: 10.1007/s11274-022-03286-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 04/12/2022] [Indexed: 10/18/2022]
Abstract
Hydroxy-mandelic acid (HMA) is widely applied in pharmaceuticals, food and cosmetics. In this study, we aimed to develop an allosteric transcription factors (aTFs) based biosensor for HMA. PobR, an aTF for HMA analog 4-hydroxybenzoic acid, was used to alter its selectivity and create novel aTFs responsive to HMA by directed evolution. We established a PobR mutant library with a capacity of 550,000 mutants using error-prone PCR and Megawhop PCR. Through our screening, two mutants were obtained with responsiveness to HMA. Analysis of each missense mutation indicating residues 122-126 were involved in its PobR ligand specificity. These results showed the effectiveness of directed evolution in switching the ligand specificity of a biosensor and improving HMA production.
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Affiliation(s)
- YaoYao Liang
- School of Life Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,Key Laboratory for Enzymes and Enzyme-Like Material Engineering of Heilongjiang, Harbin, Heilongjiang, 150040, People's Republic of China
| | - Juan Luo
- School of Life Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Chenhao Yang
- Aulin College, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Shuning Guo
- Aulin College, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Bowen Zhang
- School of Life Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Fengqianrui Chen
- Aulin College, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Kairui Su
- School of Life Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Yulong Zhang
- School of Life Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Yi Dong
- Aulin College, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Zhihao Wang
- Aulin College, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China.,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Hongda Fu
- NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China
| | - Guangchao Sui
- School of Life Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China. .,Aulin College, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China. .,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China. .,Northeast Forestry University, No. 26 Hexing Road, Harbin, 150000, People's Republic of China.
| | - Pengchao Wang
- School of Life Science, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China. .,Aulin College, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China. .,NEFU-China iGEM Team, Northeast Forestry University, Harbin, 150040, Heilongjiang, People's Republic of China. .,Key Laboratory for Enzymes and Enzyme-Like Material Engineering of Heilongjiang, Harbin, Heilongjiang, 150040, People's Republic of China. .,Northeast Forestry University, No. 26 Hexing Road, Harbin, 150000, People's Republic of China.
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14
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Fu CB, Qu JJ, Yu XF, Cheng JB, Li Q. Triple proton transfer after water rearrangement in (2,6-aza)Ind·(H2O)2. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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15
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Schwaab G, Pérez de Tudela R, Mani D, Pal N, Roy TK, Gabas F, Conte R, Durán Caballero L, Ceotto M, Marx D, Havenith M. Zwitter Ionization of Glycine at Outer Space Conditions due to Microhydration by Six Water Molecules. PHYSICAL REVIEW LETTERS 2022; 128:033001. [PMID: 35119904 DOI: 10.1103/physrevlett.128.033001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 08/09/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
We investigate glycine microsolvation with water molecules, mimicking astrophysical conditions, in our laboratory by embedding these clusters in helium nanodroplets at 0.37 K. We recorded mass selective infrared spectra in the frequency range 1500-1800 cm^{-1} where two bands centered at 1630 and 1724 cm^{-1} were observed. By comparison with the extensive accompanying calculations, the band at 1630 cm^{-1} was assigned to the COO^{-} asymmetric stretching mode of the zwitter ion and the band at 1724 cm^{-1} was assigned to redshifted C=O stretch within neutral clusters. We show that zwitter ion formation of amino acids readily occurs with only few water molecules available even under extreme conditions.
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Affiliation(s)
- Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | | | - Devendra Mani
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh 208016, India
| | - Nitish Pal
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Tarun Kumar Roy
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Fabio Gabas
- Dipartimento di Chimica, Università degli Studi di Milano, 20133 Milano, Italy
| | - Riccardo Conte
- Dipartimento di Chimica, Università degli Studi di Milano, 20133 Milano, Italy
| | | | - Michele Ceotto
- Dipartimento di Chimica, Università degli Studi di Milano, 20133 Milano, Italy
| | - Dominik Marx
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780 Bochum, Germany
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16
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Baweja S, Chowdhury PR, Maity S. Excited state hydrogen atom transfer pathways in 2,7-diazaindole - S 1-3 (S = H 2O and NH 3) clusters. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 265:120386. [PMID: 34560582 DOI: 10.1016/j.saa.2021.120386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/17/2021] [Accepted: 09/06/2021] [Indexed: 06/13/2023]
Abstract
The photoinduced tautomerization reactions via hydrogen atom transfer in the excited electronic state (ESHT) have been computationally investigated in 2,7-diazaindole (27DAI) - (H2O)1-3 and 27DAI - (NH3)1-3 isolated clusters to understand the role of various solvent wires. Two competing ESHT reaction pathways originating from the N(1)-H group to the neighbouring N(7) (R(1H-Sn-7H)) and N(2) (R(1H-Sn-2H)) atoms were rigorously examined for each system. Both one- and two-dimensional potential energy surfaces have been calculated in the excited state to investigate the pathways. The R(1H-Sn-7H) was found to be the dominant route with reaction barriers ranging from 26-40 kJmol-1 for water clusters, and 14-26 kJmol-1 for ammonia clusters. The barrier heights for ammonia clusters were found to be nearly half of the that observed for the water systems. The lengthening of the solvent chain up to two molecules resulted in a drastic decrease in the barrier heights for R(1H-Sn-7H). The barriers of the competing reaction channel R(1H-Sn-2H) were found to be significantly higher (31-127 kJmol-1) but were observed to be decreasing with the lengthening of the solvent wire as in the R(1H-Sn-7H) pathway. In both the reactions, the angle strain present in the transition state structures was dependent upon the solvent chain's length and was most likely the governing factor for the barrier heights in each solvent cluster. The results have also affirmed that the ammonia molecule is a better candidate for hydrogen transfer than water because of its higher gas-phase basicity. The results delineated from this investigation can pave the way to unravel the excited-state hydrogen atom transfer pathways in novel N-H bearing molecules.
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Affiliation(s)
- Simran Baweja
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana 502285, India
| | | | - Surajit Maity
- Department of Chemistry, IIT Hyderabad, Kandi, Sangareddy, Telangana 502285, India.
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17
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Scollo F, Evci H, Amaro M, Jurkiewicz P, Sykora J, Hof M. What Does Time-Dependent Fluorescence Shift (TDFS) in Biomembranes (and Proteins) Report on? Front Chem 2021; 9:738350. [PMID: 34778202 PMCID: PMC8586494 DOI: 10.3389/fchem.2021.738350] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
The organization of biomolecules and bioassemblies is highly governed by the nature and extent of their interactions with water. These interactions are of high intricacy and a broad range of methods based on various principles have been introduced to characterize them. As these methods view the hydration phenomena differently (e.g., in terms of time and length scales), a detailed insight in each particular technique is to promote the overall understanding of the stunning “hydration world.” In this prospective mini-review we therefore critically examine time-dependent fluorescence shift (TDFS)—an experimental method with a high potential for studying the hydration in the biological systems. We demonstrate that TDFS is very useful especially for phospholipid bilayers for mapping the interfacial region formed by the hydrated lipid headgroups. TDFS, when properly applied, reports on the degree of hydration and mobility of the hydrated phospholipid segments in the close vicinity of the fluorophore embedded in the bilayer. Here, the interpretation of the recorded TDFS parameters are thoroughly discussed, also in the context of the findings obtained by other experimental techniques addressing the hydration phenomena (e.g., molecular dynamics simulations, NMR spectroscopy, scattering techniques, etc.). The differences in the interpretations of TDFS outputs between phospholipid biomembranes and proteins are also addressed. Additionally, prerequisites for the successful TDFS application are presented (i.e., the proper choice of fluorescence dye for TDFS studies, and TDFS instrumentation). Finally, the effects of ions and oxidized phospholipids on the bilayer organization and headgroup packing viewed from TDFS perspective are presented as application examples.
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Affiliation(s)
- Federica Scollo
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Hüseyin Evci
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Mariana Amaro
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Jan Sykora
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the CAS, Prague, Czechia
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18
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Chansen W, Kungwan N. Theoretical Insights into Excited-State Intermolecular Proton Transfers of 2,7-Diazaindole in Water Using a Microsolvation Approach. J Phys Chem A 2021; 125:5314-5325. [PMID: 34125551 DOI: 10.1021/acs.jpca.1c03120] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The detailed excited-state intermolecular proton transfer (ESInterPT) mechanism of 2,7-diazaindole with water wires consisting of either one or two shells [2,7-DAI(H2O)n; n = 1-5] has been theoretically explored by time-dependent density functional theory using microsolvation with an implicit solvent model. On the basis of the excited-state potential energy surfaces along the proton transfer (PT) coordinates, among all 2,7-DAI(H2O)n, the multiple ESInterPT of 2,7-DAI(H2O)2+3 through the first hydration shell (inner circuit) is the most easy process to occur with the lowest PT barrier and a highly exothermic reaction. The lowest PT barrier resulted from the outer three waters pushing the inner circuit waters to be much closer to 2,7-DAI, leading to the enhanced intermolecular hydrogen-bonding strength of the inner two waters. Moreover, on-the-fly dynamic simulations show that the multiple ESInterPT mechanism of 2,7-DAI(H2O)2+3 is the triple PT in a stepwise mechanism with the highest PT probability. This solvation effect using microsolvation and dynamic simulation is a cost-effect approach to reveal the solvent-assisted multiple proton relay of chromophores based on excited-state proton transfer.
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Affiliation(s)
- Warinthon Chansen
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.,Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Nawee Kungwan
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.,Center of Excellence in Material Science and Technology, Chiang Mai University, Chiang Mai 50200, Thailand
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19
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Micikas RJ, Ahmed IA, Acharyya A, Smith AB, Gai F. Tuning the electronic transition energy of indole via substitution: application to identify tryptophan-based chromophores that absorb and emit visible light. Phys Chem Chem Phys 2021; 23:6433-6437. [PMID: 33710175 DOI: 10.1039/d0cp06710e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Fluorescent amino acids (FAAs) offer significant advantages over fluorescent proteins in applications where the fluorophore size needs to be limited or minimized. A long-sought goal in biological spectroscopy/microcopy is to develop visible FAAs by modifying the indole ring of tryptophan. Herein, we examine the absorption spectra of a library of 4-substituted indoles and find that the frequency of the absorption maximum correlates linearly with the global electrophilicity index of the substituent. This finding permits us to identify two promising candidates, 4-formyltryptophan (4CHO-Trp) and 4-nitrotryptophan (4NO2-Trp), both of which can be excited by visible light. Further fluorescence measurements indicate that while 4CHO-indole (and 4CHO-Trp) emits cyan fluorescence with a reasonably large quantum yield (ca. 0.22 in ethanol), 4NO2-indole is essentially non-fluorescent, suggesting that 4CHO-Trp (4NO2-Trp) could be useful as a fluorescence reporter (quencher). In addition, we present a simple method for synthesizing 4CHO-Trp.
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Affiliation(s)
- Robert J Micikas
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, USA.
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20
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Nho HW, Park JH, Adhikari A, Kwon OH. Acid–base reaction of a cationic hydration probe in vicinity of anionic interface of AOT reverse micelles. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115270] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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Temperature effect on water dynamics in tetramer phosphofructokinase matrix and the super-arrhenius respiration rate. Sci Rep 2021; 11:383. [PMID: 33431895 PMCID: PMC7801438 DOI: 10.1038/s41598-020-79271-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 11/26/2020] [Indexed: 11/08/2022] Open
Abstract
Advances in understanding the temperature effect on water dynamics in cellular respiration are important for the modeling of integrated energy processes and metabolic rates. For more than half a century, experimental studies have contributed to the understanding of the catalytic role of water in respiration combustion, yet the detailed water dynamics remains elusive. We combine a super-Arrhenius model that links the temperature-dependent exponential growth rate of a population of plant cells to respiration, and an experiment on isotope labeled 18O2 uptake to H218O transport role and to a rate-limiting step of cellular respiration. We use Phosphofructokinase (PFK-1) as a prototype because this enzyme is known to be a pacemaker (a rate-limiting enzyme) in the glycolysis process of respiration. The characterization shows that PFK-1 water matrix dynamics are crucial for examining how respiration (PFK-1 tetramer complex breathing) rates respond to temperature change through a water and nano-channel network created by the enzyme folding surfaces, at both short and long (evolutionary) timescales. We not only reveal the nano-channel water network of PFK-1 tetramer hydration topography but also clarify how temperature drives the underlying respiration rates by mapping the channels of water diffusion with distinct dynamics in space and time. The results show that the PFK-1 assembly tetramer possesses a sustainable capacity in the regulation of the water network toward metabolic rates. The implications and limitations of the reciprocal-activation-reciprocal-temperature relationship for interpreting PFK-1 tetramer mechanisms are briefly discussed.
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22
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Adhikari A, Park WW, Kwon OH. Hydrogen-Bond Dynamics and Energetics of Biological Water. Chempluschem 2020; 85:2657-2665. [PMID: 33305536 DOI: 10.1002/cplu.202000744] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/26/2020] [Indexed: 11/11/2022]
Abstract
Water molecules in the immediate vicinity of biomacromolecules and biomimetic organized assemblies often exhibit a markedly distinct behavior from that of their bulk counterparts. The overall sluggish behavior of biological water substantially affects the stability and integrity of biomolecules, as well as the successful execution of various crucial water-mediated biochemical phenomena. In this Minireview, insights are provided into the features of truncated hydrogen-bond networks that grant biological water its unique characteristics. In particular, experimental results and theoretical investigations, based on chemical kinetics, are presented that have shed light on the dynamics and energetics governing such characteristics. It is emphasized how such details help us to understand the energetics of biological water, an aspect relatively less explored than its dynamics. For instance, when biological water at hydrophilic or charged protein surfaces was explored, the free energy of H-bond breakage was found to be of the order of 0.4 kcal mol-1 higher than that of bulk water.
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Affiliation(s)
- Aniruddha Adhikari
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), 44919, Ulsan, Republic of Korea.,Department of Physics, UNIST, 44919, Ulsan, Republic of Korea
| | - Won-Woo Park
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), 44919, Ulsan, Republic of Korea
| | - Oh-Hoon Kwon
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), 44919, Ulsan, Republic of Korea.,Center for Soft and Living Matter, Institute for Basic Science (IBS), 44919, Ulsan, Republic of Korea
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23
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Jia L, Liu Y. The effects of electron-withdrawing and electron-donating groups on the photophysical properties and ESIPT of salicylideneaniline. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 242:118719. [PMID: 32717523 DOI: 10.1016/j.saa.2020.118719] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
The photophysical properties and excited state intramolecular proton transfer (ESIPT) of salicylideneaniline (1a) and its derivatives (1b-1e) with different substituents have been investigated using the DFT and TD-DFT methods. The calculated results indicate that the introduction of electron-withdrawing group CN weakens the intramolecular hydrogen bond (H···N). However, the introduction of electron-donating group N(CH3)2 strengthens it. When the CN and N(CH3)2 groups are introduced simultaneously, the intramolecular hydrogen bond (H···N) is weakened. In addition, swapping the CN and N(CH3)2 group positions can enhance the intramolecular hydrogen bond (H···N). Compared to 1a, the absorption and emission spectra of compounds 1b-1e are red-shifted. Frontier molecular orbital analyses prove that the more intense intramolecular charge transfer characters caused by CN and N(CH3)2 substituents is responsible for the red shift of spectra. Potential energy curves indicate that ESIPT in salicylideneaniline (1a) and the CN substituted derivative (1b) is a non-barrier process, while in the N(CH3)2 substituted derivative (1c) and the CN and N(CH3)2 co-substituted derivative (1d), ESIPT needs to overcome the energy barriers of 2.32 kcal/mol and 3.38 kcal/mol, respectively. Exchanging the positions of CN and N(CH3)2 groups (1e) makes the ESIPT into a barrier-free process. Therefore, the substitution and position of CN and N(CH3)2 groups can affect the ESIPT process and induce different photophysical properties.
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Affiliation(s)
- Lifeng Jia
- School of Physics, Henan Normal University, Xinxiang 453007, China.
| | - Yufang Liu
- School of Physics, Henan Normal University, Xinxiang 453007, China
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24
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Fang H. A theoretical study on water-assisted excited state double proton transfer process in substituted 2,7-diazaindole-H2O complex. Theor Chem Acc 2020. [DOI: 10.1007/s00214-020-02655-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Jiang HK, Wang YH, Weng JH, Kurkute P, Li CL, Lee MN, Chen PJ, Tseng HW, Tsai MD, Wang YS. Probing the Active Site of Deubiquitinase USP30 with Noncanonical Tryptophan Analogues. Biochemistry 2020; 59:2205-2209. [PMID: 32484330 DOI: 10.1021/acs.biochem.0c00307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Methanosarcina mazei pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA have been evolved to generate genetically encoded noncanonical amino acids (ncAAs). Use of tryptophan (Trp) analogues with pyrrole ring modification for their spatial and polarity tuning in enzyme activity and substrate specificity is still limited. Herein, we report the application of an evolved PylRS, FOWRS2, for efficient incorporation of five Trp analogues into the deubiquitinase USP30 to decipher the role of W475 for diubiquitin selectivity. Structures of the five FOWRS-C/Trp analogue complexes at 1.7-2.5 Å resolution showed multiple ncAA binding modes. The W475 near the USP30 active site was replaced with Trp analogues, and the effect on the activity as well as the selectivity toward diubiquitin linkage types was examined. It was found that the Trp analogue with a formyl group attached to the nitrogen atom of the indole ring led to an improved activity of USP30 likely due to enhanced polar interactions and that another Trp analogue, 3-benzothienyl-l-alanine, induced a unique K6-specificity. Collectively, genetically encoded noncanonical Trp analogues by evolved PylRS·tRNACUAPyl pair unravel the spatial role of USP30-W475 in its diubiquitin selectivity.
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Affiliation(s)
- Han-Kai Jiang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.,Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan.,Department of Chemistry, National Tsing Hua University, Hsinchu 300044, Taiwan
| | - Yi-Hui Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - Jui-Hung Weng
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Prashant Kurkute
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.,Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan.,Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chien-Lung Li
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - Man-Nee Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Pei-Jung Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Hsueh-Wei Tseng
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan
| | - Ming-Daw Tsai
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - Yane-Shih Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.,Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan
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26
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Muto T, Harada M, Fukuhara G, Okada T. Ice Confinement-Induced Solubilization and Aggregation of Cyanonaphthol Revealed by Fluorescence Spectroscopy and Lifetime Measurements. J Phys Chem B 2020; 124:3734-3742. [PMID: 32295346 DOI: 10.1021/acs.jpcb.0c01451] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
When an aqueous salt solution freezes, a freeze-concentrated solution (FCS) separates from the ice. The properties of the FCS may differ from those of a supercooled bulk solution of the same ionic strength at the same temperature. The fluorescence and lifetime characteristics of 6-cyano-2-naphthol (6CN) were studied in frozen NaCl solutions in order to provide insight into the solution properties of the FCS. While the photoacidity of 6CN in an FCS is similar to that in solution, several anomalous behaviors are observed. Fluorescence spectra indicate that the solubility of 6CN is significantly enhanced in the FCS (50 mM or higher) compared to that in the bulk NaCl solution where the solubility limit is 250 μM. The high solubility induces the aggregation of 6CN in the FCS, which is not detected in bulk solutions. This trend becomes marked as the initial NaCl concentration decreases and the FCS is confined in a small space. The fluorescence lifetimes of 6CN in the FCS support the spectroscopy results. In addition to the species identified by fluorescence spectroscopy, excimers are assigned from lifetime measurements in the FCS. The excimer formation is also a result of the enhanced solubility of 6CN in the FCS.
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Affiliation(s)
- Tomoya Muto
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
| | - Makoto Harada
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
| | - Gaku Fukuhara
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan.,Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Tetsuo Okada
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
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27
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Duan A, An S, Xue J, Zheng X, Zhao Y. Absorption, fluorescence, Raman spectroscopic and density functional theoretical studies on the singlet and triplet excited state decay of 3-amino-5-mercapto-1,2,4-triazole. RSC Adv 2020; 10:13442-13450. [PMID: 35492984 PMCID: PMC9051463 DOI: 10.1039/d0ra01628d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 03/11/2020] [Indexed: 11/21/2022] Open
Abstract
The excited state decay process of N-heterocyclic compounds is attracting increasing attention due to their fundamental applications in pharmaceutical and biological sciences. In this study, 3-amino-5-mercapto-1,2,4-triazole (AMT) was investigated in solid, protic, and aprotic solvents using vibrational and electronic spectroscopies combined with density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations. The steady absorption and resonance Raman spectra indicated that the AMT structure was quite sensitive to the polarity and proton of the solvent, and the pH environments. The intermolecular hydrogen bonding may contribute significantly to the decay channels of the singlet excited S2(ππ*) state process. Moreover, ns-transient absorption spectroscopy detected the short-time triplet species with ∼200 ns lifetime in solvents. The DFT and TDDFT calculations interpreted the photophysical and photochemical process from the excited S2(ππ*) state, including the singlet and triplet decay mechanisms.
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Affiliation(s)
- Aimin Duan
- Department of Chemistry, Engineering Research Center for Eco-dyeing and Finishing of Textiles, Key Laboratory of Advanced Textiles Materials and Manufacture Technology, Ministry of Education, Zhejiang Sci-Tech University Hangzhou 310018 China
| | - Suosuo An
- Department of Chemistry, Engineering Research Center for Eco-dyeing and Finishing of Textiles, Key Laboratory of Advanced Textiles Materials and Manufacture Technology, Ministry of Education, Zhejiang Sci-Tech University Hangzhou 310018 China
| | - Jiadan Xue
- Department of Chemistry, Engineering Research Center for Eco-dyeing and Finishing of Textiles, Key Laboratory of Advanced Textiles Materials and Manufacture Technology, Ministry of Education, Zhejiang Sci-Tech University Hangzhou 310018 China
| | - Xuming Zheng
- Department of Chemistry, Engineering Research Center for Eco-dyeing and Finishing of Textiles, Key Laboratory of Advanced Textiles Materials and Manufacture Technology, Ministry of Education, Zhejiang Sci-Tech University Hangzhou 310018 China
| | - Yanying Zhao
- Department of Chemistry, Engineering Research Center for Eco-dyeing and Finishing of Textiles, Key Laboratory of Advanced Textiles Materials and Manufacture Technology, Ministry of Education, Zhejiang Sci-Tech University Hangzhou 310018 China
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28
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Chao WC, Lu JF, Wang JS, Chiang TH, Lin LJ, Lee YL, Chou PT. Unveiling the structural features of nonnative trimers of human superoxide dismutase 1. Biochim Biophys Acta Gen Subj 2019; 1864:129483. [PMID: 31734464 DOI: 10.1016/j.bbagen.2019.129483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/16/2019] [Accepted: 10/29/2019] [Indexed: 01/21/2023]
Abstract
BACKGROUND Human SOD1 contains a single tryptophan residue (W32) which has been identified as a site of oxidative modification and a potentiator of aggregation involving in familial amyotrophic lateral sclerosis (fALS). In situ substitution of a tryptophan analog, 2,6-diazatryptophan ((2,6-aza)Trp) with its unique water-catalyzed proton transfer property, into proteins exhibits extraordinary sensitivity in the detection of subtle water-associated structural changes with only a few micro-molar concentration of samples. METHODS A combination of size-exclusion chromatography and water-catalyzed fluorescent emission was utilized to probe the structural features of metastable SOD1 nonnative trimers, the potential neurotoxic species in the fALS. RESULTS The monomer of apo-A4V SOD1 exhibits variable conformations and the fastest trimeric formation rate compared to that of wild type and I113T. The trimeric A4V SOD1 exhibits the least water molecules surrounding the W32, while I113T and the wild type appear to have more water molecules in the proximity of W32. A small molecule stabilizer, 5-fluorouridine, effects the structural conformation of SOD1 nonnative trimers. CONCLUSIONS Our studies unveil new insights into water-associated structural changes of SOD1 nonnative trimers and demonstrate that in situ incorporation of (2,6-aza)Trp is a sensitive and powerful tool for probing subtle changes of water environments during protein aggregation. GENERAL SIGNIFICANCE The water-sensitive probe, (2,6-aza)Trp, demonstrates superior sensitivity for detecting modulation of water microsolvation, structural conformation during oligomer formation and 5FUrd binding to both wild type and mutant SOD1.
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Affiliation(s)
- Wei-Chih Chao
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan; School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jinn-Shyan Wang
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
| | - Tzu-Hsuan Chiang
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan; School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Li-Ju Lin
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan; School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Yao-Lin Lee
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
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29
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Gao H, Yang X, Zhang T, Yang D. Investigation on the excited state intramolecular proton transfer process for the novel 2‐(3,5‐dichloro‐2‐hydroxy‐phenyl)‐benzooxazole‐5‐carboxylicacid system. J PHYS ORG CHEM 2019. [DOI: 10.1002/poc.3989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Haiyan Gao
- College of Physics and ElectronicsNorth China University of Water Resources and Electric Power Zhengzhou China
| | - Xiaohui Yang
- College of Physics and ElectronicsNorth China University of Water Resources and Electric Power Zhengzhou China
| | - Tianjie Zhang
- College of Physics and ElectronicsNorth China University of Water Resources and Electric Power Zhengzhou China
| | - Dapeng Yang
- College of Physics and ElectronicsNorth China University of Water Resources and Electric Power Zhengzhou China
- State Key Laboratory of Molecular Reaction Dynamics, Theoretical and Computational ChemistryDalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian China
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30
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The azatryptophan-based fluorescent platform for in vitro rapid screening of inhibitors disrupting IKKβ-NEMO interaction. Bioorg Chem 2018; 81:504-511. [DOI: 10.1016/j.bioorg.2018.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 09/04/2018] [Accepted: 09/06/2018] [Indexed: 01/24/2023]
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31
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Sheng W, Nairat M, Pawlaczyk PD, Mroczka E, Farris B, Pines E, Geiger JH, Borhan B, Dantus M. Ultrafast Dynamics of a “Super” Photobase. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201806787] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Wei Sheng
- Department of Chemistry Michigan State University E. Lansing MI 48824 USA
| | - Muath Nairat
- Department of Chemistry Michigan State University E. Lansing MI 48824 USA
| | | | - Elizabeth Mroczka
- Department of Chemistry Michigan State University E. Lansing MI 48824 USA
| | - Benjamin Farris
- Department of Chemistry Michigan State University E. Lansing MI 48824 USA
| | - Ehud Pines
- Department of Chemistry Ben-Gurion University of the Negev POB 653 Beer Sheva 84105 Israel
| | - James H. Geiger
- Department of Chemistry Michigan State University E. Lansing MI 48824 USA
| | - Babak Borhan
- Department of Chemistry Michigan State University E. Lansing MI 48824 USA
| | - Marcos Dantus
- Department of Chemistry Michigan State University E. Lansing MI 48824 USA
- Department of Physics and Astronomy Michigan State University East Lansing MI 48824 USA
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32
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Sheng W, Nairat M, Pawlaczyk PD, Mroczka E, Farris B, Pines E, Geiger JH, Borhan B, Dantus M. Ultrafast Dynamics of a "Super" Photobase. Angew Chem Int Ed Engl 2018; 57:14742-14746. [PMID: 30152115 DOI: 10.1002/anie.201806787] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/26/2018] [Indexed: 11/08/2022]
Abstract
Molecular reactivity can change dramatically with the absorption of a photon due to the difference of the electronic configurations between the excited and ground states. Here we report on the discovery of a modular system (Schiff base formed from an aldehyde and an amine) that upon photoexcitation yields a more basic imine capable of intermolecular proton transfer from protic solvents. Ultrafast dynamics of the excited state conjugated Schiff base reveals the pathway for proton transfer, culminating in a 14-unit increase in pKa to give the excited state pKa * >20 in ethanol.
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Affiliation(s)
- Wei Sheng
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA
| | - Muath Nairat
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA
| | - Patrick D Pawlaczyk
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA
| | - Elizabeth Mroczka
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA
| | - Benjamin Farris
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA
| | - Ehud Pines
- Department of Chemistry, Ben-Gurion University of the Negev, POB 653, Beer Sheva, 84105, Israel
| | - James H Geiger
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA
| | - Babak Borhan
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA
| | - Marcos Dantus
- Department of Chemistry, Michigan State University, E. Lansing, MI, 48824, USA.,Department of Physics and Astronomy, Michigan State University, East Lansing, MI, 48824, USA
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33
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Kroeger AA, Karton A. A computational foray into the mechanism and catalysis of the adduct formation reaction of guanine with crotonaldehyde. J Comput Chem 2018; 40:630-637. [DOI: 10.1002/jcc.25595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 08/21/2018] [Accepted: 08/23/2018] [Indexed: 01/18/2023]
Affiliation(s)
- Asja A. Kroeger
- School of Molecular Sciences The University of Western Australia Perth Western Australia 6009 Australia
| | - Amir Karton
- School of Molecular Sciences The University of Western Australia Perth Western Australia 6009 Australia
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34
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Tu TH, Chen YT, Chen YA, Wei YC, Chen YH, Chen CL, Shen JY, Chen YH, Ho SY, Cheng KY, Lee SL, Chen CH, Chou PT. The Cyclic Hydrogen-Bonded 6-Azaindole Trimer and its Prominent Excited-State Triple-Proton-Transfer Reaction. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800944] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ting-Hsun Tu
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yi-Ting Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yi-An Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yu-Chen Wei
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - You-Hua Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Chi-Lin Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Jiun-Yi Shen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yi-Han Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Ssu-Yu Ho
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Kum-Yi Cheng
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Shern-Long Lee
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Chun-hsien Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Pi-Tai Chou
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
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35
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Tu TH, Chen YT, Chen YA, Wei YC, Chen YH, Chen CL, Shen JY, Chen YH, Ho SY, Cheng KY, Lee SL, Chen CH, Chou PT. The Cyclic Hydrogen-Bonded 6-Azaindole Trimer and its Prominent Excited-State Triple-Proton-Transfer Reaction. Angew Chem Int Ed Engl 2018; 57:5020-5024. [DOI: 10.1002/anie.201800944] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 02/14/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Ting-Hsun Tu
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yi-Ting Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yi-An Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yu-Chen Wei
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - You-Hua Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Chi-Lin Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Jiun-Yi Shen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Yi-Han Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Ssu-Yu Ho
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Kum-Yi Cheng
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Shern-Long Lee
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Chun-hsien Chen
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
| | - Pi-Tai Chou
- Department of Chemistry; National Taiwan University; Taipei 10617 Taiwan
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36
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Tang Z, Qi Y, Wang Y, Zhou P, Tian J, Fei X. Excited-State Proton Transfer Mechanism of 2,6-Diazaindoles·(H2O)n (n = 2–4) Clusters. J Phys Chem B 2018. [DOI: 10.1021/acs.jpcb.7b10207] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Zhe Tang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, China
| | | | | | - Panwang Zhou
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, China
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37
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Chao WC, Lin LJ, Lu JF, Wang JS, Lin TC, Chen YH, Chen YT, Yang HC, Chou PT. Unveiling the water-associated conformational mobility in the active site of ascorbate peroxidase. Biochim Biophys Acta Gen Subj 2018; 1862:451-459. [PMID: 29104043 DOI: 10.1016/j.bbagen.2017.10.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 10/27/2017] [Accepted: 10/30/2017] [Indexed: 11/25/2022]
Abstract
We carried out comprehensive spectroscopic studies of wild type and mutants of ascorbate peroxidase (APX) to gain understanding of the conformational mobility of the active site. In this approach, three unnatural tryptophans were applied to replace the distal tryptophan (W41) in an aim to probe polarity/water environment near the edge of the heme-containing active site. 7-azatryptophan ((7-aza)Trp) is sensitive to environment polarity, while 2,7-azatryptophan ((2,7-aza)Trp) and 2,6-diazatryptophan ((2,6-aza)Trp) undergo excited-state water-catalyzed double and triple proton transfer, respectively, and are sensitive to the water network. The combination of their absorption, emission bands and the associated relaxation dynamics of these fluorescence probes, together with the Soret-band difference absorption and resonance Raman spectroscopy, lead us to unveil the water associated conformational mobility in the active site of APX. The results are suggestive of the existence of equilibrium between two different environments surrounding W41 in APX, i.e., the water-rich and water-scant forms with distinct fluorescence relaxation. Our results thus demonstrate for the first time the power of integrating multiple sensors (7-aza)Trp, (2,7-aza)Trp and (2,6-aza)Trp in probing the water environment of a specifically targeted Trp in proteins.
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Affiliation(s)
- Wei-Chih Chao
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan; School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan; Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Li-Ju Lin
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan; Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
| | - Jinn-Shyan Wang
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.
| | - Tzu-Chieh Lin
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Yi-Han Chen
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Yi-Ting Chen
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Hsiao-Ching Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
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38
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Tu TH, Chen YT, Shen JY, Lin TC, Chou PT. Excited-State Proton Transfer in 3-Cyano-7-azaindole: From Aqueous Solution to Ice. J Phys Chem A 2018; 122:2479-2484. [DOI: 10.1021/acs.jpca.8b00379] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ting-Husn Tu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Ting Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Jiun-Yi Shen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Ta-Chun Lin
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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39
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Lv J, Yang D. Theoretical investigation on ESIPT mechanism for a novel Sal-3,4-benzophen system. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2017. [DOI: 10.1142/s0219633617500730] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this work, we theoretically investigate the properties of excited state process for a novel salicylidene sal-3,4-benzophen (Sal-3,4-B) system, which contains two intramolecular hydrogen bonds (O1-H2[Formula: see text]N3 and O4-H5[Formula: see text]N6). Based on the density functional theory (DFT) and time-dependent DFT (TDDFT) methods, we find these two hydrogen bonds should be strengthened in the S1 state, while the O4-H5[Formula: see text]N6 one could be largely affected upon the excitation process. Analyses about infrared (IR) vibrational spectra about hydrogen bond moieties also confirm this viewpoint. Frontier molecular orbitals (MOs) depict the nature of electronic excited state and support the excited state intramolecular proton transfer (ESIPT) reaction.Two kinds of stepwise potential energy curves of Sal-3,4-B in the S1 state demonstrate that only one proton could be transferred. Also based on constructing potential energy curves, the synergetic situation could be eliminated. Due to the specific ESIPT mechanism for Sal-3,4-B, we successfully explain the previous experiment and provide a reasonable attribution to the second emission peak of experiment.
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Affiliation(s)
- Jian Lv
- College of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou 450046, P. R. China
| | - Dapeng Yang
- College of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou 450046, P. R. China
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
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40
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Yang HC, Yang CH, Huang MY, Lu JF, Wang JS, Yeh YQ, Jeng US. Homology Modeling and Molecular Dynamics Simulation Combined with X-ray Solution Scattering Defining Protein Structures of Thromboxane and Prostacyclin Synthases. J Phys Chem B 2017; 121:11229-11240. [PMID: 29168638 DOI: 10.1021/acs.jpcb.7b08299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A combination of molecular dynamics (MD) simulations and X-ray scattering (SAXS) has emerged as the approach of choice for studying protein structures and dynamics in solution. This approach has potential applications for membrane proteins that neither are soluble nor form crystals easily. We explore the water-coupled dynamic structures of thromboxane synthase (TXAS) and prostacyclin synthase (PGIS) from scanning HPLC-SAXS measurements combined with MD ensemble analyses. Both proteins are heme-containing enzymes in the cytochrome P450 family, known as prostaglandin H2 (PGH2) isomerase, with counter-functions in regulation of platelet aggregation. Currently, the X-ray crystallographic structures of PGIS are available, but those for TXAS are not. The use of homology modeling of the TXAS structure with ns-μs explicit water solvation MD simulations allows much more accurate estimation of the configuration space with loop motion and origin of the protein behaviors in solution. In contrast to the stability of the conserved PGIS structure in solution, the pronounced TXAS flexibility has been revealed to have unstructured loop regions in connection with the characteristic P450 structural elements. The MD-derived and experimental-solution SAXS results are in excellent agreement. The significant protein internal motions, whole-molecule structures, and potential problems with protein folding, crystallization, and functionality are examined.
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Affiliation(s)
- Hsiao-Ching Yang
- Department of Chemistry, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Cheng-Han Yang
- Department of Chemistry, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Ming-Yi Huang
- Department of Chemistry, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Jinn-Shyan Wang
- School of Medicine, Fu Jen Catholic University , New Taipei City 24205, Taiwan
| | - Yi-Qi Yeh
- National Synchrotron Radiation Research Center , Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - U-Ser Jeng
- National Synchrotron Radiation Research Center , Hsinchu Science Park, Hsinchu 30076, Taiwan.,Department of Chemical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan
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41
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Liu Y, Tang Z, Wang Y, Tian J, Fei X, Cao F, Li G. Theoretical study of excited-state proton transfer of 2,7-diazaindole·(H 2O) 2 cluster via hydrogen bonding dynamics. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 187:163-167. [PMID: 28686917 DOI: 10.1016/j.saa.2017.06.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 06/10/2017] [Accepted: 06/30/2017] [Indexed: 06/07/2023]
Abstract
A new chromophore, 2,7-diazaindole (2,7-DAI), has been designed to surpass the limitation of 7-azaindole (7AI). It exhibits remarkable water catalyzed proton-transfer properties. Excited-state proton transfer (ESPT) has been investigated based on the time-dependent density functional theory method. The calculated vertical excitation energies in the S0 and S1 states agree well with the experimental values. Proton transfer couples with hydrogen-bonding dynamics between the 2,7-diazaindole and the surrounding water molecules. Hydrogen bond strengthening has been testified in the S1 state based on a comparison of primary bond lengths and hydrogen bond energy that is involved in the intermolecular hydrogen bond between the S0 and S1 states. Frontier molecular further suggest that the electron density changes between the ground and excited states serve as basic driving forces for proton transfer. We determined the potential-energy curves of the S0 and S1 states to characterize the ESPT process. This work explains that the ESPT process for 2,7-DAI·(H2O)2 clusters at the molecular level, and highlights the importance of hydrogen bonding in ESPT.
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Affiliation(s)
- Yuan Liu
- School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China
| | - Zhe Tang
- School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China
| | - Yi Wang
- School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China.
| | - Jing Tian
- School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China
| | - Xu Fei
- School of Textile and Material Engineering, Dalian Polytechnic University, Dalian 116034, China
| | - Fang Cao
- School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China
| | - GuangYue Li
- College of Chemical Engineering, North China University of Science and Technology, Tangshan, 063009, China.
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42
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Yi J, Fang H. Theoretical Study on the Substituent Effect on the Excited-State Proton Transfer in the 7-Azaindole-Water Derivatives. Photochem Photobiol 2017; 94:27-35. [DOI: 10.1111/php.12839] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 08/21/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Jiacheng Yi
- Department of Chemistry and Material Science; College of Science; Nanjing Forestry University; Nanjing Jiangsu China
| | - Hua Fang
- Department of Chemistry and Material Science; College of Science; Nanjing Forestry University; Nanjing Jiangsu China
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43
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Srinivasadesikan V, Lu CH, Ramachandran B, Lee SL. Effects of Microsolvation on the Electronic Properties of Sarcosine: A Computational Study. ChemistrySelect 2017. [DOI: 10.1002/slct.201701430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Venkatesan Srinivasadesikan
- Department of Chemistry and Biochemistry; National Chung Cheng University; Taiwan
- Centre of Excellence in Advanced Materials, Division of Chemistry, Vignan's Foundation for Science; Technology and Research University (VFSTRU), Vadlamudi; Guntur 522 213, Andhra Pradesh India
| | - Chih-Hung Lu
- Department of Chemistry and Biochemistry; National Chung Cheng University; Taiwan
| | - Balajee Ramachandran
- Department of chemistry; University of Southern California, California; United States 90089
| | - Shyi-Long Lee
- Department of Chemistry and Biochemistry; National Chung Cheng University; Taiwan
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44
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Chao WC, Shen JY, Yang CH, Lan YK, Yuan JH, Lin LJ, Yang HC, Lu JF, Wang JS, Wee K, Chen YH, Chou PT. The In Situ Tryptophan Analogue Probes the Conformational Dynamics in Asparaginase Isozymes. Biophys J 2017; 110:1732-1743. [PMID: 27119634 DOI: 10.1016/j.bpj.2016.03.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 03/10/2016] [Accepted: 03/21/2016] [Indexed: 11/19/2022] Open
Abstract
Dynamic water solvation is crucial to protein conformational reorganization and hence to protein structure and functionality. We report here the characterization of water dynamics on the L-asparaginase structural homology isozymes L-asparaginases I (AnsA) and II (AnsB), which are shown via fluorescence spectroscopy and dynamics in combination with molecular dynamics simulation to have distinct catalytic activity. By use of the tryptophan (Trp) analog probe 2,7-diaza-tryptophan ((2,7-aza)Trp), which exhibits unique water-catalyzed proton-transfer properties, AnsA and AnsB are shown to have drastically different local water environments surrounding the single Trp. In AnsA, (2,7-aza)Trp exhibits prominent green N(7)-H emission resulting from water-catalyzed excited-state proton transfer. In stark contrast, the N(7)-H emission is virtually absent in AnsB, which supports a water-accessible and a water-scant environment in the proximity of Trp for AnsA and AnsB, respectively. In addition, careful analysis of the emission spectra and corresponding relaxation dynamics, together with the results of molecular dynamics simulations, led us to propose two structural states associated with the rearrangement of the hydrogen-bond network in the vicinity of Trp for the two Ans. The water molecules revealed in the proximity of the Trp residue have semiquantitative correlation with the observed emission spectral variations of (2,7-aza)Trp between AnsA and AnsB. Titration of aspartate, a competitive inhibitor of Ans, revealed an increase in N(7)-H emission intensity in AnsA but no obvious spectral changes in AnsB. The changes in the emission profiles reflect the modulation of structural states by locally confined environment and trapped-water collective motions.
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Affiliation(s)
- Wei-Chih Chao
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jiun-Yi Shen
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Cheng-Han Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Yi-Kang Lan
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jui-Hung Yuan
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Li-Ju Lin
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Hsiao-Ching Yang
- Department of Chemistry, Fu Jen Catholic University, New Taipei City, Taiwan.
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Jinn-Shyan Wang
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Kevin Wee
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - You-Hua Chen
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry and Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei, Taiwan.
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Chung KY, Chen YH, Chen YT, Hsu YH, Shen JY, Chen CL, Chen YA, Chou PT. The Excited-State Triple Proton Transfer Reaction of 2,6-Diazaindoles and 2,6-Diazatryptophan in Aqueous Solution. J Am Chem Soc 2017; 139:6396-6402. [DOI: 10.1021/jacs.7b01672] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Kun-You Chung
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Yi-Han Chen
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Yi-Ting Chen
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Yen-Hao Hsu
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Jiun-Yi Shen
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Chi-Lin Chen
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Yi-An Chen
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Pi-Tai Chou
- Department of Chemistry and
Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan, R.O.C
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46
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Triggering comprehensive enhancement in oxygen evolution reaction by using newly created solvent. Sci Rep 2016; 6:28456. [PMID: 27328821 PMCID: PMC4916470 DOI: 10.1038/srep28456] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/02/2016] [Indexed: 11/09/2022] Open
Abstract
Theoretical calculations indicate that the properties of confined liquid water, or liquid water at surfaces, are dramatically different from those of liquid bulk water. Here we present an experimentally innovative strategy on comprehensively efficient oxygen evolution reaction (OER) utilizing plasmon-induced activated water, creating from hot electron decay at resonantly illuminated Au nanoparticles (NPs). Compared to conventional deionized (DI) water, the created water owns intrinsically reduced hydrogen-bonded structure and a higher chemical potential. The created water takes an advantage in OER because the corresponding activation energy can be effectively reduced by itself. Compared to DI water-based solutions, the OER efficiencies at Pt electrodes increased by 69.3%, 21.1% and 14.5% in created water-based acidic, neutral and alkaline electrolyte solutions, respectively. The created water was also effective for OERs in photoelectrochemically catalytic and in inert systems. In addition, the efficiency of OER increased by 47.5% in created water-based alkaline electrolyte solution prepared in situ on a roughened Au electrode. These results suggest that the created water has emerged as an innovative activator in comprehensively effective OERs.
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47
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Chen YT, Chao WC, Kuo HT, Shen JY, Chen IH, Yang HC, Wang JS, Lu JF, Cheng RP, Chou PT. Probing the polarity and water environment at the protein-peptide binding interface using tryptophan analogues. Biochem Biophys Rep 2016; 7:113-118. [PMID: 28955897 PMCID: PMC5613298 DOI: 10.1016/j.bbrep.2016.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 05/16/2016] [Accepted: 05/31/2016] [Indexed: 11/18/2022] Open
Abstract
7-Azatryptophan and 2,7-diazatryptophan are sensitive to polarity changes and water content, respectively, and should be ideal for studying protein-protein and protein-peptide interactions. In this study, we replaced the tryptophan in peptide Baa (LKWKKLLKLLKKLLKLG-NH2) with 7-azatryptophan or 2,7-diazatryptophan, forming (7-aza)Trp-Baa and (2,7-aza)Trp-Baa, to study the calmodulin (CaM)-peptide interaction. Dramatic differences in the (7-aza)Trp-Baa and (2,7-aza)Trp-Baa fluorescence properties between free peptide in water and calmodulin-bound peptide were observed, showing a less polar and water scant environment at the binding interface of the peptide upon calmodulin binding. The affinity of the peptides for binding CaM followed the trend Baa (210±10 pM)<(7-aza)Trp-Baa (109±5 pM)<(2,7-aza)Trp-Baa (45±2 pM), showing moderate increase in binding affinity upon increasing the number of nitrogen atoms in the Trp analogue. The increased binding affinity may be due to the formation of more hydrogen bonds upon binding CaM for the Trp analogue with more nitrogen atoms. Importantly, the results demonstrate that (7-aza)Trp and (2,7-aza)Trp are excellent probes for exploring the environment at the interface of protein-peptide interactions.
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Affiliation(s)
- Yi-Ting Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Chih Chao
- Department of Chemistry, Fu-Jen Catholic University, New Taipei City 24205, Taiwan
| | - Hsiou-Ting Kuo
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Jiun-Yi Shen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - I-Han Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Hsiao-Ching Yang
- Department of Chemistry, Fu-Jen Catholic University, New Taipei City 24205, Taiwan
| | - Jinn-Shyan Wang
- School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan
| | - Jyh-Feng Lu
- School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan
| | - Richard P. Cheng
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
- Corresponding authors.
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
- Corresponding authors.
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48
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Top-emitting quantum dots light-emitting devices employing microcontact printing with electricfield-independent emission. Sci Rep 2016; 6:22530. [PMID: 26932521 PMCID: PMC4773764 DOI: 10.1038/srep22530] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 02/17/2016] [Indexed: 11/08/2022] Open
Abstract
Recent breakthroughs in quantum dot light-emitting devices (QD-LEDs) show their promise in the development of next-generation displays. However, the QD-LED with conventional ITO-based bottom emission structure is difficult to realize the high aperture ratio, electricfield-independent emission and flexible full-color displays. Hence, we demonstrate top-emitting QD-LEDs with dry microcontact printing quantum dot films. The top-emitting structure is proved to be able to accelerate the excitons radiative transition rate, then contributing to stable electroluminescent efficiency with a very low roll-off, and preventing spectra from shifting and broadening with the electric field increases. The results suggest potential routes towards creating high aperture ratio, wide color gamut, color-stable and flexible QD-LED displays.
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49
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Chen HC, Mai FD, Hwang BJ, Lee MJ, Chen CH, Wang SH, Tsai HY, Yang CP, Liu YC. Creation of Electron-doping Liquid Water with Reduced Hydrogen Bonds. Sci Rep 2016; 6:22166. [PMID: 26916099 PMCID: PMC4768145 DOI: 10.1038/srep22166] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/09/2016] [Indexed: 11/09/2022] Open
Abstract
The strength of hydrogen bond (HB) decides water's property and activity. Here we propose the mechanisms on creation and persistence of innovatively prepared liquid water, which is treated by Au nanoparticles (AuNPs) under resonant illumination of green-light emitting diode (LED) to create Au NP-treated (sAuNT) water, with weak HB at room temperature. Hot electron transfer on resonantly illuminated AuNPs, which is confirmed from Au LIII-edge X-ray absorption near edge structure (XANES) spectra, is responsible for the creation of negatively charged sAuNT water with the incorporated energy-reduced hot electron. This unique electronic feature makes it stable at least for one week. Compared to deionized (DI) water, the resulting sAuNT water exhibits many distinct properties at room temperature. Examples are its higher activity revealed from its higher vapor pressure and lower specific heat. Furthermore, Mpemba effect can be successfully explained by our purposed hypothesis based on sAuNT water-derived idea of water energy and HB.
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Affiliation(s)
- Hsiao-Chien Chen
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University No. 250, Wuxing St., Taipei 11031, Taiwan
| | - Fu-Der Mai
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University No. 250, Wuxing St., Taipei 11031, Taiwan
| | - Bing-Joe Hwang
- Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 10607, Taiwan
| | - Ming-Jer Lee
- Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 10607, Taiwan
| | - Ching-Hsiang Chen
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, 43 Keelung Rd., Sec. 4, Taipei 10607, Taiwan
| | - Shwu-Huey Wang
- Core Facility Center, Office of Research and Development, Taipei Medical University, No. 250, Wuxing St., Taipei 11031, Taiwan
| | - Hui-Yen Tsai
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University No. 250, Wuxing St., Taipei 11031, Taiwan
| | - Chih-Ping Yang
- Graduate Institute of Medical Science, College of Medicine, Taipei Medical University, No. 250, Wuxing St., Taipei, Taiwan
| | - Yu-Chuan Liu
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University No. 250, Wuxing St., Taipei 11031, Taiwan
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50
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Yang CP, Chen HC, Wang CC, Tsai PW, Ho CW, Liu YC. Effective Energy Transfer via Plasmon-Activated High-Energy Water Promotes Its Fundamental Activities of Solubility, Ionic Conductivity, and Extraction at Room Temperature. Sci Rep 2015; 5:18152. [PMID: 26658304 PMCID: PMC4674797 DOI: 10.1038/srep18152] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/13/2015] [Indexed: 11/08/2022] Open
Abstract
Water is a ubiquitous solvent in biological, physical, and chemical processes. Unique properties of water result from water's tetrahedral hydrogen-bonded (HB) network (THBN). The original THBN is destroyed when water is confined in a nanosized environment or localized at interfaces, resulting in corresponding changes in HB-dependent properties. In this work, we present an innovative idea to validate the reserve energy of high-energy water and applications of high-energy water to promote water's fundamental activities of solubility, ionic conductivity, and extraction at room temperature. High-energy water with reduced HBs was created by utilizing hot electrons with energies from the decay of surface plasmon excited at gold (Au) nanoparticles (NPs). Compared to conventional deionized (DI) water, solubilities of alkali metal-chloride salts in high-energy water were significantly increased, especially for salts that release heat when dissolved. The ionic conductivity of NaCl in high-energy water was also markedly higher, especially when the electrolyte's concentration was extremely low. In addition, antioxidative components, such as polyphenols and 2,3,5,4'-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG) from teas, and Polygonum multiflorum (PM), could more effectively be extracted using high-energy water. These results demonstrate that high-energy water has emerged as a promising innovative solvent for promoting water's fundamental activities via effective energy transfer.
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Affiliation(s)
- Chih-Ping Yang
- Graduate Institute of Medical Science, College of Medicine, Taipei Medical University, 250 Wuxing St., Taipei 11031, Taiwan
| | - Hsiao-Chien Chen
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing St., Taipei 11031, Taiwan
| | - Ching-Chiung Wang
- School of Pharmacy, College of Pharmacy, Taipei Medical University, 250 Wuxing St., Taipei 11031, Taiwan
| | - Po-Wei Tsai
- School of Pharmacy, College of Pharmacy, Taipei Medical University, 250 Wuxing St., Taipei 11031, Taiwan
| | - Chia-Wen Ho
- Center for Cancer Research, Taipei Medical University, 250 Wuxing St., Taipei 11031, Taiwan
| | - Yu-Chuan Liu
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing St., Taipei 11031, Taiwan
- Biomedical Mass Imaging Research Center, Taipei Medical University, 250 Wuxing St., Taipei 11031, Taiwan
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