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Sati SC, Pant CK, Bhatt P, Pandey Y. Thymine Adsorption onto Cation Exchanged Montmorillonite Clay: Role of Biogenic Divalent Metal Cations in Prebiotic Processes of Chemical Evolution. ORIGINS LIFE EVOL B 2022; 52:233-247. [DOI: 10.1007/s11084-022-09633-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 11/01/2022] [Indexed: 11/26/2022]
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Saroha B, Kumar A, Raman Maurya R, Lal M, Kumar S, Kumar Rajor H, Bahadur I, Singh Negi D. Adsorption of cysteine on metal(II) octacynaomolybdate(IV) at different pH values: Surface complexes characterization by FT-IR, SEM with EDXA, CHNS and Langmuir isotherm analysis. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.118197] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Beltrami G, Martucci A, Pasti L, Chenet T, Ardit M, Gigli L, Cescon M, Suard E. L-Lysine Amino Acid Adsorption on Zeolite L: a Combined Synchrotron, X-Ray and Neutron Diffraction Study. ChemistryOpen 2020; 9:978-982. [PMID: 33024651 PMCID: PMC7528762 DOI: 10.1002/open.202000183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/24/2020] [Indexed: 11/13/2022] Open
Abstract
Combined neutron and X-ray powder diffraction techniques highlighted the sorption capacity of the acidic L zeolite towards the L-lysine amino acid. The role of zeolite channels in the stabilization of the lysine absorbed and the effect of water on protein structure are elucidated at atomistic level. The stabilization of the L α-helical conformation is related to strong H-bonds between the tail aminogroups of lysine molecules and the Brønsted acid site as well as to complex intermolecular H-bond system between water molecules, zeolite and amino acid. This finding is relevant in the catalytic synthesis of polypeptide, as well as in industrial biotechnology by qualitatively predicting binding behaviour.
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Affiliation(s)
- Giada Beltrami
- Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy
| | - Annalisa Martucci
- Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy
| | - Luisa Pasti
- Dipartimento di Scienze Chimiche e Farmaceutiche, University of Ferrara, Via Fossato di Mortara 17, 44121, Ferrara, Italy
| | - Tatiana Chenet
- Dipartimento di Scienze Chimiche e Farmaceutiche, University of Ferrara, Via Fossato di Mortara 17, 44121, Ferrara, Italy
| | - Matteo Ardit
- Department of Physics and Earth Sciences, University of Ferrara, Via Saragat 1, 44121, Ferrara, Italy
| | - Lara Gigli
- Elettra-Sincrotrone Trieste S.C.p.A., Materials Characterisation by X-ray diffraction (MCX) beamline Strada, Statale, 14 - km 163,5 in AREA Science Park, Basovizza, Trieste, Italy
| | - Mirco Cescon
- Dipartimento di Scienze Chimiche e Farmaceutiche, University of Ferrara, Via Fossato di Mortara 17, 44121, Ferrara, Italy
| | - Emmanuelle Suard
- Institute Max Von Laue and Paul Langevin, D2B beamline BP156, 38042, Grenoble, France
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Sun Z, Huang M, Liu C, Fang G, Chen N, Zhou D, Gao J. The formation of •OH with Fe-bearing smectite clays and low-molecular-weight thiols: Implication of As(III) removal. WATER RESEARCH 2020; 174:115631. [PMID: 32114017 DOI: 10.1016/j.watres.2020.115631] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 01/25/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Low-molecular-weight thiols (LMWTs) are widely occurring in waters and soils, which can act as electron shuttles in biogeochemical cycles. It is interesting to study the interactions between LMWTs and clay minerals, which would produce free radicals on clay surfaces and influence As(III) transformation. Batch experiments and spectroscopic analysis in combined with computational modeling were conducted with three Fe-bearing clay minerals (Na-NAu-1, Na-NAu-2 and Na-SAz-2) and four LMWTs (l-cysteine, cysteamine, homocysteine, and glutathione) to investigate the reaction mechanisms of LMWTs with Fe-bearing clay minerals and influences of clay types and LMWT structures on the interactions. The results showed that Fe-bearing clay minerals can improve 2.4-3.7 times of •OH formation in 96-h LMWTs oxidation. Quenching experiments confirmed surface-Fenton-like reactions were the main pathways of •OH formation in the presence of Fe-bearing smectite clay minerals. The most possible hypothesis is that structural Fe (III) can accept electrons from LMWTs through proton-coupled transfer from -SH functional group, which was supported by FTIR, XRD and Mössbauer spectroscopies. The results of DFT calculations suggested that clay surfaces could accelerate RS• formation and stabilize the radicals. The addition of Na-NAu-2 in the cystein solution could increase As(III) oxidation to As(V) from 16.3% to 42.0%. The results imply that in-situ •OH formation in the presence of LMWTs and smectite clays may be an important geochemical process for the transformation of environmental contaminants.
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Affiliation(s)
- Zhaoyue Sun
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Meiying Huang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cun Liu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China
| | - Guodong Fang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China
| | - Ning Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Dongmei Zhou
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province, 210023, China
| | - Juan Gao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science Chinese Academy of Sciences, Nanjing, 210008, China.
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Jatav S, Furlan KP, Liu J, Hill EH. Heterostructured Monolayer MoS 2 Nanoparticles toward Water-Dispersible Catalysts. ACS APPLIED MATERIALS & INTERFACES 2020; 12:19813-19822. [PMID: 32227875 DOI: 10.1021/acsami.0c02246] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
MoS2 is a 2D semiconductor where exfoliation to a single layer results in improved catalytic properties. However, its high surface energy can lead to extensive aggregation, resulting in degraded catalytic performance and stability. Combined with a lack of dispersibility in water, this represents a pitfall for catalysis in the aqueous phase. Herein, we present the use of nanoscopic layered silicates pillared with a cationic surfactant to template the growth of MoS2 in the interlayer space. This provides heterostructured layered nanoparticles ∼25 nm wide by 3-8 nm thick containing isolated MoS2 layers. The resulting nanohybrids retain the disc-like morphology and surface chemistry of the clays, providing good aqueous stability, while also providing access to the catalytic edge-sites of the MoS2 layer. In addition to significant enhancement of catalytic dye degradation, molecular aggregation on the highly charged clay interface is comparable to unmodified clays. These particles are ideal for studies of charge-transport properties in confined semiconductor layers, as well as hierarchical self-assembly into functional materials. This study paves the way to colloidal synthesis of nanoparticulate heterostructures with other functional layered materials, particularly where particle exfoliation, covalent modification, and aqueous stability are concerns.
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Affiliation(s)
- Sanjay Jatav
- Institute of Advanced Ceramics, Hamburg University of Technology, Hamburg 21073, Germany
| | - Kaline P Furlan
- Institute of Advanced Ceramics, Hamburg University of Technology, Hamburg 21073, Germany
| | - Junying Liu
- Institute of Advanced Ceramics, Hamburg University of Technology, Hamburg 21073, Germany
| | - Eric H Hill
- Institute of Advanced Ceramics, Hamburg University of Technology, Hamburg 21073, Germany
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Samulewski RB, Gonçalves JM, Urbano A, da Costa ACS, Ivashita FF, Paesano A, Zaia DAM. Magnetite Synthesis in the Presence of Cyanide or Thiocyanate under Prebiotic Chemistry Conditions. Life (Basel) 2020; 10:E34. [PMID: 32252332 PMCID: PMC7236013 DOI: 10.3390/life10040034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 11/24/2022] Open
Abstract
Magnetite is an iron oxide mineral component of primitive Earth. It is naturally synthesized in different ways, such as magma cooling as well as olivine decomposition under hydrothermal conditions. It is probable magnetite played a significant role in biogenesis. The seawater used in the current work contained high Mg2+, Ca2+ and SO42- concentrations, unlike the seawater of today that has high Na+ and Cl- concentrations. It is likely that this seawater better resembled the ion composition of the seas of the Earth from 4 billion years ago. Cyanide and thiocyanate were common molecules in prebiotic Earth, and especially in primitive oceans, where they could act on the magnetite mechanism synthesis via Fe2+ interaction. In this research, magnetite samples that were synthesized under prebiotic conditions in the presence of cyanide or thiocyanate, (both with and without artificial seawater), showed that, besides magnetite, goethite and ferrihydrite can be produced through different Fe2+-ion interactions. Cyanide apparently acts as a protective agent for magnetite production; however, thiocyanate and seawater 4.0 Gy ions produced goethite and ferrihydrite at different ratios. These results validate that Fe3+ oxides/hydroxides were possibly present in primitive Earth, even under anoxic conditions or in the absence of UV radiation. In addition, the results show that the composition of water in early oceans should not be neglected in prebiotic chemistry experiments, since this composition directly influences mineral formation.
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Affiliation(s)
- Rafael Block Samulewski
- Departamento de Química, Universidade Estadual de Londrina, CEP 86057-970 Londrina, PR, Brazil;
| | - Josué Martins Gonçalves
- Departamento de Química Fundamental, Universidade de São Paulo-USP, CEP 05508-000 São Paulo, SP, Brazil;
| | - Alexandre Urbano
- Departamento de Física-CCE, Universidade Estadual de Londrina, CEP 86057-970 Londrina, PR, Brazil;
| | | | - Flávio F. Ivashita
- Departamento de Física-CCE, Universidade Estadual de Maringá, 87020-900 Maringá, PR, Brazil; (F.F.I.); (A.P.J.)
| | - Andrea Paesano
- Departamento de Física-CCE, Universidade Estadual de Maringá, 87020-900 Maringá, PR, Brazil; (F.F.I.); (A.P.J.)
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Hu C, Hu H, Song M, Tan J, Huang G, Zuo J. Preparation, characterization, and Cd(II) sorption of/on cysteine-montmorillonite composites synthesized at various pH. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:10599-10606. [PMID: 31942713 DOI: 10.1007/s11356-019-07550-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/29/2019] [Indexed: 06/10/2023]
Abstract
Montmorillonite-cysteine could be used as the immobilizer, detector, and detoxifier of heavy metals. To further the understanding and the application, the interaction between the montmorillonite and cysteine and the adsorption of cysteine on montmorillonite and characterization of the composites need to be studied further. In present work, the effects of pH, contact time and initial concentration of cysteine on the adsorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Cd(II) adsorption on the composites were conducted to characterize the composites synthesized at different pH conditions. The results showed that the adsorption amount of cysteine on montmorillonite decreased with the increase of pH in the range of 2.4-8.0, reached equilibrium in about 1 min and increased with the initial concentration of cysteine and reached the maximum at 160 mg/g. The adsorption data fitted with Langmuir better than Freundlich, fitted with first-order and second-order better than the intraparticle diffusion model. XRD patterns and FTIR spectra showed that the interlayer spacing of the composite synthesized in the range of pH 2.4-4.3 was larger than that at pH 4.5-8.0 and the bonding of cysteine and montmorillonite mainly depended on the action of the amino group. Adsorption of Cd(II) on composites indicated more cysteine loaded (pH < 4.5) composite had greater capacity for Cd(II). The above results demonstrated that the composite synthesized under lower pH could retain more active cysteine, which might be beneficial to its various applications.
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Affiliation(s)
- Chao Hu
- Key Laboratory for Quality Control of Characteristic Fruits and Vegetables of Hubei Province, College of Life Science and Technology,, Hubei Engineering University, Xiaogan, 432000, China.
| | - Hongqing Hu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Mengdie Song
- Key Laboratory for Quality Control of Characteristic Fruits and Vegetables of Hubei Province, College of Life Science and Technology,, Hubei Engineering University, Xiaogan, 432000, China
| | - Ju Tan
- Key Laboratory for Quality Control of Characteristic Fruits and Vegetables of Hubei Province, College of Life Science and Technology,, Hubei Engineering University, Xiaogan, 432000, China
| | - Guoyong Huang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jichao Zuo
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China
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Villafañe-Barajas SA, Baú JPT, Colín-García M, Negrón-Mendoza A, Heredia-Barbero A, Pi-Puig T, Zaia DAM. Salinity Effects on the Adsorption of Nucleic Acid Compounds on Na-Montmorillonite: a Prebiotic Chemistry Experiment. ORIGINS LIFE EVOL B 2018; 48:181-200. [PMID: 29392543 DOI: 10.1007/s11084-018-9554-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 01/08/2018] [Indexed: 10/18/2022]
Abstract
Any proposed model of Earth's primitive environments requires a combination of geochemical variables. Many experiments are prepared in aqueous solutions and in the presence of minerals. However, most sorption experiments are performed in distilled water, and just a few in seawater analogues, mostly inconsistent with a representative primitive ocean model. Therefore, it is necessary to perform experiments that consider the composition and concentration of dissolved salts in the early ocean to understand how these variables could have affected the absorption of organic molecules into minerals. In this work, the adsorption of adenine, adenosine, and 5'AMP onto Na+montmorillonite was studied using a primitive ocean analog (4.0 Ga) from experimental and computational approaches. The order of sorption of the molecules was: 5'AMP > adenine > adenosine. Infrared spectra showed that the interaction between these molecules and montmorillonite occurs through the NH2 group. In addition, electrostatic interaction between negatively charged montmorillonite and positively charge N1 of these molecules could occur. Results indicate that dissolved salts affect the sorption in all cases; the size and structure of each organic molecule influence the amount sorbed. Specifically, the X-ray diffraction patterns show that dissolved salts occupy the interlayer space in Na-montmorillonite and compete with organic molecules for available sites. The adsorption capacity is clearly affected by dissolved salts in thermodynamic terms as deduced by isotherm models. Indeed, molecular dynamic models suggest that salts are absorbed in the interlamellar space and can interact with oxygen atoms exposed in the edges of clay or in its surface, reducing the sorption of the organic molecules. This research shows that the sorption process could be affected by high concentration of salts, since ions and organic molecules may compete for available sites on inorganic surfaces. Salt concentration in primitive oceans may have strongly affected the sorption, and hence the concentration processes of organic molecules on minerals.
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Affiliation(s)
- Saúl A Villafañe-Barajas
- Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Cd. Mx., México
- Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Cd. Mx., México
| | - João Paulo T Baú
- Laboratório de Química Prebiótica, Departamento de Química-CCE, Universidade Estadual de Londrina, Londrina, PR, 86051-990, Brazil
| | - María Colín-García
- Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Cd. Mx., México.
| | - Alicia Negrón-Mendoza
- Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Cd. Mx., México
| | - Alejandro Heredia-Barbero
- Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Cd. Mx., México
| | - Teresa Pi-Puig
- Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, C.P. 04510, Cd. Mx., México
| | - Dimas A M Zaia
- Laboratório de Química Prebiótica, Departamento de Química-CCE, Universidade Estadual de Londrina, Londrina, PR, 86051-990, Brazil.
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Dzade NY, Roldan A, de Leeuw NH. Surface and shape modification of mackinawite (FeS) nanocrystals by cysteine adsorption: a first-principles DFT-D2 study. Phys Chem Chem Phys 2016; 18:32007-32020. [DOI: 10.1039/c6cp05913a] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The surface and shape modulation of mackinawite (FeS) nanoparticles by amino acid cysteine adsorption is investigated using a first-principles density functional theory calculations, corrected for dispersion-interactions (DFT-D2).
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Affiliation(s)
- N. Y. Dzade
- Department of Earth Sciences
- Utrecht University
- Utrecht
- The Netherlands
| | - A. Roldan
- School of Chemistry
- Cardiff University
- Cardiff
- UK
| | - N. H. de Leeuw
- Department of Earth Sciences
- Utrecht University
- Utrecht
- The Netherlands
- School of Chemistry
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Liu X, Eusterhues K, Thieme J, Ciobota V, Höschen C, Mueller CW, Küsel K, Kögel-Knabner I, Rösch P, Popp J, Totsche KU. STXM and NanoSIMS investigations on EPS fractions before and after adsorption to goethite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:3158-3166. [PMID: 23451805 DOI: 10.1021/es3039505] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Extracellular polymeric substances (EPS) are expected to be an important source for the formation of mineral-organic associations in soil. Because such formations affect the composition of mobile and immobile organic matter as well as the reactivity of minerals, we investigated the composition of EPS before and after adsorption to goethite. Raman measurements on EPS extracted from Bacillus subtilis distinguished four fractions rich in proteins, polysaccharides, lipids, or lipids and proteins. Scanning transmission X-ray microscopy identified three different EPS-fractions that varied in their composition in proteins, nonaromatic proteins, and polysaccharides. Reaction of EPS with goethite led to a preferential adsorption of lipids and proteins. The organic coverage was heterogeneous, consisting of ~100 × 200 nm large patches of either lipid-rich or protein-rich material. Nanoscale secondary ion mass spectrometry showed a strong S enrichment in aggregates of ~400 nm in the goethite adsorbed EPS. From our simplified model system, we learned that only a small portion (<10%) of EPS was immobilized via adsorption to goethite. This fraction formed a coating of subμm spaced protein-rich and lipid-rich domains, i.e., of two materials which will strongly differ in their reactive sites. This will finally affect further adsorption, the particle mobility and eventually also colloidal stability.
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Affiliation(s)
- Xinran Liu
- Institut für Geowissenschaften, Friedrich-Schiller-Universität Jena, Germany
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Carneiro CEA, Berndt G, de Souza Junior IG, de Souza CMD, Paesano A, da Costa ACS, di Mauro E, de Santana H, Zaia CTBV, Zaia DAM. Adsorption of adenine, cytosine, thymine, and uracil on sulfide-modified montmorillonite: FT-IR, Mössbauer and EPR spectroscopy and X-ray diffractometry studies. ORIGINS LIFE EVOL B 2011; 41:453-68. [PMID: 21717172 DOI: 10.1007/s11084-011-9244-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 06/18/2011] [Indexed: 10/18/2022]
Abstract
In the present work the interactions of nucleic acid bases with and adsorption on clays were studied at two pHs (2.00, 7.00) using different techniques. As shown by Mössbauer and EPR spectroscopies and X-ray diffractometry, the most important finding of this work is that nucleic acid bases penetrate into the interlayer of the clays and oxidize Fe(2+) to Fe(3+), thus, this interaction cannot be regarded as a simple physical adsorption. For the two pHs the order of the adsorption of nucleic acid bases on the clays was: adenine ≈ cytosine > thymine > uracil. The adsorption of adenine and cytosine on clays increased with decreasing of the pH. For unaltered montmorillonite this result could be explained by electrostatic forces between adenine/cytosine positively charged and clay negatively charged. However for montmorillonite modified with Na(2)S, probably van der Waals forces also play an important role since both adenine/cytosine and clay were positively charged. FT-IR spectra showed that the interaction between nucleic acid bases and clays was through NH(+) or NH (2) (+) groups. X-ray diffractograms showed that nucleic acid bases adsorbed on clays were distributed into the interlayer surface, edge sites and external surface functional groups (aluminol, silanol) EPR spectra showed that the intensity of the line g ≈ 2 increased probably because the oxidation of Fe(2+) to Fe(3+) by nucleic acid bases and intensity of the line g = 4.1 increased due to the interaction of Fe(3+) with nucleic acid bases. Mössbauer spectra showed a large decreased on the Fe(2+) doublet area of the clays due to the reaction of nucleic acid bases with Fe(2+).
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Affiliation(s)
- Cristine E A Carneiro
- Laboratório de Química Prebiótica, Departamento de Química-CCE, Universidade Estadual de Londrina, PR, Brazil
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Carneiro CEA, de Santana H, Casado C, Coronas J, Zaia DAM. Adsorption of amino acids (ALA, CYS, HIS, MET) on zeolites: fourier transform infrared and Raman spectroscopy investigations. ASTROBIOLOGY 2011; 11:409-418. [PMID: 21671763 DOI: 10.1089/ast.2010.0521] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Minerals adsorb more amino acids with charged R-groups than amino acids with uncharged R-groups. Thus, the peptides that form from the condensation of amino acids on the surface of minerals should be composed of amino acid residues that are more charged than uncharged. However, most of the amino acids (74%) in today's proteins have an uncharged R-group. One mechanism with which to solve this paradox is the use of organophilic minerals such as zeolites. Over the range of pH (pH 2.66-4.50) used in these experiments, the R-group of histidine (His) is positively charged and neutral for alanine (Ala), cysteine (Cys), and methionine (Met). In acidic hydrothermal environments, the pH could be even lower than those used in this study. For the pH range studied, the zeolites were negatively charged, and the overall charge of all amino acids was positive. The conditions used here approximate those of prebiotic Earth. The most important finding of this work is that the relative concentrations of each amino acid (X=His, Met, Cys) to alanine (X/Ala) are close to 1.00. This is an important result with regard to prebiotic chemistry because it could be a solution for the paradox stated above. Pore size did not affect the adsorption of Cys and Met on zeolites, and the Si/Al ratio did not affect the adsorption of Cys, His, and Met. ZSM-5 could be used for the purification of Cys from other amino acids (Student-Newman-Keuls test, p<0.05), and mordenite could be used for separation of amino acids from each other (Student-Newman-Keuls test, p<0.05). As shown by Fourier transform infrared (FT-IR) spectra, Ala interacts with zeolites through the [Formula: see text] group, and methionine-zeolite interactions involve the COO, [Formula: see text], and CH(3) groups. FT-IR spectra show that the interaction between the zeolites and His is weak. Cys showed higher adsorption on all zeolites; however, the hydrophobic Van der Waals interaction between zeolites and Cys is too weak to produce any structural changes in the Cys groups (amine, carboxylic, sulfhydryl, etc.); thus, the FT-IR and Raman spectra are the same as those of solid Cys.
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Vieira AP, Berndt G, de Souza Junior IG, Di Mauro E, Paesano A, de Santana H, da Costa ACS, Zaia CTBV, Zaia DAM. Adsorption of cysteine on hematite, magnetite and ferrihydrite: FT-IR, Mössbauer, EPR spectroscopy and X-ray diffractometry studies. Amino Acids 2010; 40:205-14. [PMID: 20524137 DOI: 10.1007/s00726-010-0635-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Accepted: 05/15/2010] [Indexed: 10/19/2022]
Abstract
In the present paper, the adsorption of cysteine on hematite, magnetite and ferrihydrite was studied using FT-IR, electron paramagnetic resonance (EPR), Mössbauer spectroscopy and X-ray diffractometry. Cysteine was dissolved in artificial seawater (two different pHs) which contains the major constituents. There were two main findings described in this paper. First, after the cysteine adsorption, the FT-IR spectroscopy and X-ray diffractometry data showed the formation of cystine. Second, the Mössbauer spectroscopy did not show any increase in the amount of Fe(2+) as expected due the oxidation of cysteine to cystine. An explanation could be that Fe(2+) was oxidized by the oxygen present in the seawater or there occurred a reduction of cystine by Fe(2+) generating cysteine and Fe(3+). The specific surface area and pH at point of zero charge of the iron oxides were influenced by adsorption of cysteine. When compared to other iron oxides, ferrihydrite adsorbed significantly (p < 0.05) more cysteine. The pH has a significant (p < 0.05) effect only on cysteine adsorption on hematite. The FT-IR spectroscopy results showed that cystine remains adsorbed on the surface of the iron oxides even after being mixed with KCl and the amine and carboxylic groups are involved in this interaction. X-ray diffractometry showed no changes on iron oxides mineralogy and the following precipitated substances were found along with the iron oxides after drying the samples: cysteine, cystine and seawater salts. The EPR spectroscopy showed that cysteine interacts with iron oxides, changing the relative amounts of iron oxides and hydroxide.
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Affiliation(s)
- Alessandra P Vieira
- Departamento de Química-CCE, Universidade Estadual de Londrina, Londrina, PR 86051-990, Brazil
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