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Adasme-Carreño F, Ochoa-Calle A, Galván M, Ireta J. Conformational preference of dipeptide zwitterions in aqueous solvents. Phys Chem Chem Phys 2024; 26:8210-8218. [PMID: 38384231 DOI: 10.1039/d3cp05742a] [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: 02/23/2024]
Abstract
Proper description of solvent effects is challenging for theoretical methods, particularly if the solute is a zwitterion. Here, a series of theoretical procedures are used to determine the preferred solvated conformations of twelve hydrophobic dipeptides (Leu-Leu, Leu-Phe, Phe-Leu, Ile-Leu, Phe-Phe, Ala-Val, Val-Ala, Ala-Ile, Ile-Ala, Ile-Val, Val-Ile and Val-Val) in the zwitterionic state. First, the accuracy of density functional theory (DFT), combined with different implicit solvent models, for describing zwitterions in aqueous solvent is assessed by comparing the predicted against the experimental glycine tautomerization energy, i.e., the energetic difference between canonical and zwitterionic glycine in aqueous solvents. It is found that among the tested solvation schemes, the charge-asymmetric nonlocally determined local-electric solvation model (CANDLE) predicts an energetic difference in excellent agreement with the experimental value. Next, DFT-CANDLE is used to determine the most favorable solvated conformation for each of the investigated dipeptide zwitterions. The CANDLE-solvated structures are obtained by exploring the conformational space of each dipeptide zwitterion concatenating DFT calculations, in vacuum, with classical molecular dynamics simulations, in explicit solvents, and DFT calculations including explicit water molecules. It is found that the energetically most favorable conformations are similar to those of the dipeptide zwitterions in their respective crystal structures. Such structural agreement is indicative of the DFT-CANDLE accomplishment of the description of solvated zwitterions, and suggests that these biomolecules self-assemble as quasi-rigid objects.
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Affiliation(s)
- Francisco Adasme-Carreño
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectorá de Investigación y Postgrado Universidad Católica del Maule, Talca 3480112, Chile.
- Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480112, Chile
| | - Alvaro Ochoa-Calle
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México 09340, Mexico.
| | - Marcelo Galván
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México 09340, Mexico.
| | - Joel Ireta
- Departamento de Química, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México 09340, Mexico.
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2
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Banaś K, Lenartowicz P, Staś M, Dziuk B, Siodłak D. Insight into the Structure of Victorin, the Host-Selective Toxin from the Oat Pathogen Cochliobolus victoriae. Studies of the Unique Dehydroamino Acid β-Chlorodehydroalanine. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37486973 PMCID: PMC10401702 DOI: 10.1021/acs.jafc.3c01387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Victorins, a family of peptide toxins, produced by the fungal pathogen Cochliobolus victoriae and responsible for disease of some oat varieties, contain a β-chlorodehydroalanine residue, ΔAla(βCl). To determine the conformational properties of this unique dehydroamino acid, a series of model compounds was studied using X-ray, NMR, and FT-IR methods, supported by theoretical calculations. The ΔAla(βCl) geometrical isomers differ in conformational profile. The isomer Z prefers the helical conformation α (φ, ψ = -61°, -24°), PPII type conformation β (φ, ψ = -47°, 136°), and semiextended conformation β2 (φ, ψ = -116°, 9°) in weakly and more polar solutions. The isomer E prefers mainly the extended conformation C5 (φ, ψ = -177°, 160°), but with an increase of the environment polarity also conformations β (φ, ψ = -44°, 132°) and α (φ, ψ = -53°, -39°). In the most stable conformations the N-H···Cl hydrogen bond (5γ) occurs, created between the chlorine atom of the side chain and the N-H donor of the flanking amide group. The method of synthesis of the β-chlorodehydroalanine residue is proposed, by chlorination of dehydroalanine and then the photoisomerization from the isomer Z to E. The presented results indicate that the assignment of the geometrical isomer of the ΔAla(βCl) residue in naturally occurring victorins still remains an open question, despite being crucial for biological activity.
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Affiliation(s)
- Karolina Banaś
- Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland
| | - Paweł Lenartowicz
- Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland
| | - Monika Staś
- Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland
| | - Błażej Dziuk
- Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
- Faculty of Chemistry, University of Wroclaw, Joliot-Curie 14, Wroclaw 50-383, Poland
| | - Dawid Siodłak
- Faculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland
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Zheng X, Yang N, Hou Y, Cai K. Dissecting amide-I vibrations in histidine dipeptide. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 292:122424. [PMID: 36750008 DOI: 10.1016/j.saa.2023.122424] [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: 09/27/2022] [Revised: 01/27/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
The amide-I vibrational characteristics and conformational preferences of the model compound - histidine dipeptide (Ac-His-NHCH3, HISD) in gas phase and solution have been revealed with the help of ab initio calculations and wavefunction analyses. The Gibbs free energy surfaces (FESs) of solvated HISD were smoothed by solvent effect to exhibit different structural populations concerning various external environments. It was shown that the most stable conformations of HISD in CHCl3 and gas phase are C7eq, while those in DMSO and water are β and PPII, respectively. Compared with ALAD, the number of accessible conformational states on these FESs was predicted to be reduced due to the steric effect of imidazole group. The two amide-I normal modes of HISD were found to have intrinsically secondary structural dependencies, and be sensitive to surrounding environments. The average amide-Ia frequencies of HISD isomers in these environments were predicted to be almost the same as those of ALAD, while the amide-Ib mean frequencies were estimated to be lower than ALAD due to the intramolecular interactions between the imidazole group and amino-terminal amide unit. The good linear correlations between amide-I frequencies and the atomic electrostatic potentials (ESPs) of amide groups were also found to interpret the solvent-induced amide-I frequency shifts of HISD at the electronic structure level. These results allow us to gain a deep understanding of amide-I vibrations of HISD, and would be helpful for the site-specific conformational monitoring and spectral interpretation of solvated polypeptides.
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Affiliation(s)
- Xuan Zheng
- College of Chemistry, Chemical Engineering and Environment, Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Fujian Provincial Key Laboratory of Pollution Monitoring and Control, Minnan Normal University, Zhangzhou 363000, PR China.
| | - Nairong Yang
- College of Chemistry, Chemical Engineering and Environment, Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Fujian Provincial Key Laboratory of Pollution Monitoring and Control, Minnan Normal University, Zhangzhou 363000, PR China
| | - Yanjun Hou
- College of Chemistry, Chemical Engineering and Environment, Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology, Fujian Provincial Key Laboratory of Pollution Monitoring and Control, Minnan Normal University, Zhangzhou 363000, PR China
| | - Kaicong Cai
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China; Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China.
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4
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Fan J, Lan H, Ning W, Zhong R, Chen F, Yan G, Cai K. Modeling amide-I vibrations of alanine dipeptide in solution by using neural network protocol. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 268:120675. [PMID: 34890871 DOI: 10.1016/j.saa.2021.120675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/27/2021] [Accepted: 11/26/2021] [Indexed: 06/13/2023]
Abstract
Infrared spectroscopy is a powerful tool for the understanding of molecular structure and function of polypeptides. Theoretical interpretation of IR spectra relies on ab initio calculations may be very costly in computational resources. Herein, we developed a neural network (NN) modeling protocol to evaluate a model dipeptide's backbone amide-I spectra. DFT calculations were performed for the amide-I vibrational motions and structural parameters of alanine dipeptide (ALAD) conformers in different micro-environments ranging from polar to non-polar ones. The obtained backbone dihedrals, C = O bond lengths and amide-I frequencies of ALAD were gather together for NN architecture. The applications of built NN protocols for the prediction of amide-I frequencies of ALAD in other solvation conditions are quite satisfactory with much less computational cost comparing with electronic structure calculations. The results show that this cost-effective way enables us to decipher the polypeptide's dynamic secondary structures and biological functions with their backbone vibrational probes.
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Affiliation(s)
- Jianping Fan
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China; Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
| | - Huaying Lan
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China
| | - Wenfeng Ning
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China
| | - Rongzhen Zhong
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China
| | - Feng Chen
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
| | - Guiyang Yan
- Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
| | - Kaicong Cai
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, PR China; Fujian Provincial Key Laboratory of Featured Biochemical and Chemical Materials, Ningde Normal University, Ningde 352100, PR China
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5
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Cai K, Zheng X, Hou Y, Chen F, Yan G, Zhuang D. Deciphering the structural preference encoded in amide-I vibrations of lysine dipeptide in gas phase and in aqueous solution. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 247:119066. [PMID: 33091736 DOI: 10.1016/j.saa.2020.119066] [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: 08/19/2020] [Revised: 10/01/2020] [Accepted: 10/06/2020] [Indexed: 06/11/2023]
Abstract
Protein's biological function is critically associated with its structural feature, which is encoded in its amino acid sequence. For evaluation of conformational fluctuation and folding mechanism, DFT calculations were performed on the model compound - lysine dipeptide (LYSD) in gas phase to demonstrate the correlation between amide-I vibrations and secondary structure. Molecular dynamics simulations were carried out for the structural dynamics of LYSD in aqueous solution. The results show that LYSD tends form C7eq, C5, β, PPII and α conformations in the gas phase and primarily presented PPII and α conformations in aqueous solution. The obtained amide-I vibrational frequencies of LYSD conformers were assigned, thus build the correlations between amide-I probes and secondary structure of LYSD. These results provide theoretical insights into the structural feature of LYSD through amide-I vibrations, and would shed light on site specific structural prediction of polypeptides.
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Affiliation(s)
- Kaicong Cai
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Fujian Province University, Ningde 352100, China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China.
| | - Xuan Zheng
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China
| | - Yanjun Hou
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China
| | - Feng Chen
- Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Fujian Province University, Ningde 352100, China
| | - Guiyang Yan
- Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Fujian Province University, Ningde 352100, China
| | - Danling Zhuang
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China
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6
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Lake PT, Mattson MA, McCullagh M. Implicit Solvation Using the Superposition Approximation (IS-SPA): Extension to Peptides in a Polar Solvent. J Chem Theory Comput 2021; 17:703-713. [PMID: 33428425 DOI: 10.1021/acs.jctc.0c01094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Efficient, accurate, and adaptable implicit solvent models remain a significant challenge in the field of molecular simulation. A recent implicit solvent model, IS-SPA, based on approximating the mean solvent force using the superposition approximation, provides a platform to achieve these goals. IS-SPA was originally developed to handle nonpolar solutes in a polar solvent and did not accurately capture polar solvation. Here, we demonstrate that IS-SPA can accurately capture polar solvation by incorporating solvent orientation and accounting for the contributions from long ranged electrostatics. Solvent orientation is approximated as that of an ideal dipole aligned in a mean electrostatic field and an analytic form of the long ranged electrostatics is derived. Parameters for the model are calculated from explicit solvent simulations of an isolated atom or molecule and include atom-based solvent densities, mean electric field functions, radially symmetric averaged Lennard-Jones forces, and multipoles of the explicit solvent model. Using these parameters, IS-SPA accounts for asymmetry of charge solvation and reproduces the explicit solvent potential of mean force of dimerization of two oppositely charged Lennard-Jones spheres in chloroform with high fidelity. Additionally, the model more accurately captures the effect of explicit solvent on the monomer and dimer configurations of alanine dipeptide in chloroform than a generalized Born or constant density dielectric model. The current version of the algorithm is expected to outperform explicit solvent simulations for aggregation of small peptides at concentrations below 150 mM, well above the typical experimental concentrations for these materials.
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Affiliation(s)
- Peter T Lake
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078-1010, United States
| | - Max A Mattson
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Martin McCullagh
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078-1010, United States
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7
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Cai K, Liu J, Liu Y, Chen F, Yan G, Lin H. Application of a transparent window vibrational probe (azido probe) to the structural dynamics of model dipeptides and amyloid β-peptide. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 227:117681. [PMID: 31685425 DOI: 10.1016/j.saa.2019.117681] [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: 08/15/2019] [Revised: 10/02/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
The azido asymmetric stretching motion is widely used for the elucidation of the intrinsic conformational preference and folding mechanism of protein since it has strong vibrational absorbance in the spectral transparent windows. However, the possible secondary structural disturbance induced by the insertion of azido group in the side chain of polypeptides should be carefully evaluated. Here, DFT calculation and enhanced sampling method were employed for model dipeptides with or without azido substitution, and the outcome results show that the lower potential energy basins of isolated model dipeptides are consistent with the preferred structural distributions of model dipeptides in aqueous solution. The azido asymmetric stretching frequency shows its sensitivity to the backbone configurations just like amide-I vibration does, and the azido vibration exhibits great potential as a structural reporter in the transparent window. For the evaluation of the application of azido group in biologically related system, the structural dynamics of Aβ37-42 and N3-Aβ37-42 fragments and the self-assemble process of their protofiliments in aqueous solution were demonstrated. The outcome results show that the structural fluctuations of Aβ37-42 and its protofilament in aqueous solution are quite similar with or without azido substitution, and the dewetting transitions of Aβ37-42 and N3-Aβ37-42 β-sheet layers are both complete within 30 ns and assemble into stable protofilaments. Therefore, the azido asymmetric vibrational motion is a minimally invasive structural probe and would not introduce much disturbance to the structural dynamics of polypeptides.
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Affiliation(s)
- Kaicong Cai
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, 361005, Fujian, PR China.
| | - Jia Liu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, 361005, Fujian, PR China
| | - Ya'nan Liu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, 361005, Fujian, PR China
| | - Feng Chen
- Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Ningde, 352100, PR China
| | - Guiyang Yan
- Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University, Ningde, 352100, PR China
| | - Huiqiu Lin
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, 350007, Fujian, PR China
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8
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Cai K, Zheng X, Liu J, Du F, Yan G, Zhuang D, Yan S. Mapping the amide-I vibrations of model dipeptides with secondary structure sensitivity and amino acid residue specificity, and its application to amyloid β-peptide in aqueous solution. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 219:391-400. [PMID: 31059891 DOI: 10.1016/j.saa.2019.04.070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 06/09/2023]
Abstract
Vibrational spectroscopy has been known as particularly well-suited for deciphering the polypeptide's structure. To decode structural information encoded in IR spectra, we developed amide-I frequency maps on the basis of model dipeptides to correlate the amide-I frequency of interest to the combination of the calculated secondary structure dependent amide-I frequency by using DFT method and the electrostatic potentials that projected onto the amide unit from the micro-environment within molecular mechanics force field. The constructed maps were applied to model dipeptides and amyloid β-peptide fragment (Aβ25-35). The dipeptide specified map (DS map) and the hybrid map (HYB map) predicted amide-I bands of Aβ25-35 in solution satisfactorily reproduce experimental observation, and indicate the preference of forming β-sheet and random coil structure for Aβ25-35 in D2O just as the results of cluster analysis suggested. These maps with secondary structural sensitivity and amino acid residue specificity open up a way for the interpretation of amide-I vibrations and show their potentials in the understanding of molecular structure of polypeptides in solution.
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Affiliation(s)
- Kaicong Cai
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, Fujian 361005, PR China; Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry, Ningde Normal University, Ningde 352100, PR China.
| | - Xuan Zheng
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, Fujian 361005, PR China
| | - Jia Liu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, Fujian 361005, PR China
| | - Fenfen Du
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, Fujian 361005, PR China
| | - Guiyang Yan
- Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry, Ningde Normal University, Ningde 352100, PR China
| | - Danling Zhuang
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, Fujian 361005, PR China
| | - Siyi Yan
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou, Fujian 350007, PR China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen, Fujian 361005, PR China
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9
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Xie T, Xiao Y, Zhao S, Hu XQ, Xu PF. Catalyst-Free Chemoselective Synthesis of 3,4-Dihydroquinazoline-2-thiones and 2-Imino[1,3]benzothiazines. J Org Chem 2016; 81:10499-10505. [DOI: 10.1021/acs.joc.6b01232] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Ting Xie
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Yu Xiao
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Shuai Zhao
- School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou 213164, P. R. China
| | - Xiu-Qin Hu
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
| | - Peng-Fei Xu
- State
Key Laboratory of Applied Organic Chemistry, College of Chemistry
and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
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10
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Cai K, Du F, Zheng X, Liu J, Zheng R, Zhao J, Wang J. General Applicable Frequency Map for the Amide-I Mode in β-Peptides. J Phys Chem B 2016; 120:1069-79. [PMID: 26824578 DOI: 10.1021/acs.jpcb.5b11643] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this work, a general applicable amide-I vibrational frequency map (GA map) for β-peptides in a number of common solvents was constructed, based on a peptide derivative, N-ethylpropionamide (NEPA). The map utilizes force fields at the ab initio computational level to accurately describe molecular structure and solute-solvent interactions, and also force fields at the molecular mechanics level to take into account long-range solute-solvent interactions. The results indicate that the GA map works reasonably for mapping the vibrational frequencies of the amide-I local-modes for β-peptides, holding promises for understanding the complicated infrared spectra of the amide-I mode in β-polypeptides.
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Affiliation(s)
- Kaicong Cai
- College of Chemistry and Chemical Engineering, Fujian Normal University , Fuzhou, Fujian 350007, P. R. China.,Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry , Xiamen, Fujian 361005, P. R. China
| | - Fenfen Du
- College of Chemistry and Chemical Engineering, Fujian Normal University , Fuzhou, Fujian 350007, P. R. China.,Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry , Xiamen, Fujian 361005, P. R. China
| | - Xuan Zheng
- College of Chemistry and Chemical Engineering, Fujian Normal University , Fuzhou, Fujian 350007, P. R. China.,Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry , Xiamen, Fujian 361005, P. R. China
| | - Jia Liu
- College of Chemistry and Chemical Engineering, Fujian Normal University , Fuzhou, Fujian 350007, P. R. China.,Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry , Xiamen, Fujian 361005, P. R. China
| | - Renhui Zheng
- Beijing National Laboratory for Molecular Sciences, Structural Chemistry of Unstable and Stable Species Laboratory, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China
| | - Juan Zhao
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China
| | - Jianping Wang
- Beijing National Laboratory for Molecular Sciences, Molecular Reaction Dynamics Laboratory, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China
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