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Popkov A, Su Z, Sigurdardóttir SB, Luo J, Malankowska M, Pinelo M. Engineering polyelectrolyte multilayer coatings as a strategy to optimize enzyme immobilization on a membrane support. Biochem Eng J 2023. [DOI: 10.1016/j.bej.2023.108838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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2
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Utilization of Clay Materials as Support for Aspergillus japonicus Lipase: An Eco-Friendly Approach. Catalysts 2021. [DOI: 10.3390/catal11101173] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Lipase is an important group of biocatalysts, which combines versatility and specificity, and can catalyze several reactions when applied in a high amount of industrial processes. In this study, the lipase produced by Aspergillus japonicus under submerged cultivation, was immobilized by physical adsorption, using clay supports, namely, diatomite, vermiculite, montmorillonite KSF (MKSF) and kaolinite. Besides, the immobilized and free enzyme was characterized, regarding pH, temperature and kinetic parameters. The most promising clay support was MKSF that presented 69.47% immobilization yield and hydrolytic activity higher than the other conditions studied (270.7 U g−1). The derivative produced with MKSF showed high stability at pH and temperature, keeping 100% of its activity throughout 12 h of incubation in the pH ranges between 4.0 and 9.0 and at a temperature from 30 to 50 °C. In addition, the immobilized lipase on MKSF support showed an improvement in the catalytic performance. The study shows the potential of using clays as support to immobilized lipolytic enzymes by adsorption method, which is a simple and cost-effective process.
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McMillan HM, Rogers N, Wadle A, Hsu-Kim H, Wiesner MR, Kuehn MJ, Hendren CO. Microbial vesicle-mediated communication: convergence to understand interactions within and between domains of life. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2021; 23:664-677. [PMID: 33899070 DOI: 10.1039/d1em00022e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
All cells produce extracellular vesicles (EVs). These biological packages contain complex mixtures of molecular cargo and have a variety of functions, including interkingdom communication. Recent discoveries highlight the roles microbial EVs may play in the environment with respect to interactions with plants as well as nutrient cycling. These studies have also identified molecules present within EVs and associated with EV surfaces that contribute to these functions. In parallel, studies of engineered nanomaterials have developed methods to track and model small particle behavior in complex systems and measure the relative importance of various surface features on transport and function. While studies of EV behavior in complex environmental conditions have not yet employed transdisciplinary approaches, it is increasingly clear that expertise from disparate fields will be critical to understand the role of EVs in these systems. Here, we outline how the convergence of biology, soil geochemistry, and colloid science can both develop and address questions surrounding the basic principles governing EV-mediated interkingdom interactions.
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Affiliation(s)
- Hannah M McMillan
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Nicholas Rogers
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Austin Wadle
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Mark R Wiesner
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA
| | - Meta J Kuehn
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA and Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
| | - Christine Ogilvie Hendren
- Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708, USA and Department of Geological and Environmental Sciences, Appalachian State University, Boone, NC 28608, USA.
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Mucha M, Maršálek R, Bukáčková M, Zelenková G. Interaction among clays and bovine serum albumin. RSC Adv 2020; 10:43927-43939. [PMID: 35517170 PMCID: PMC9058406 DOI: 10.1039/d0ra01430c] [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: 02/14/2020] [Accepted: 11/19/2020] [Indexed: 11/23/2022] Open
Abstract
Interactions between bovine serum albumin and various clays including pure clay minerals and bentonite were studied with the aim to describe the interaction process. The adsorption of albumin on the clays is strongly affected by the behavior of clays in the aquatic environment (hydrolysis and release of cations). A sufficient amount of albumin was adsorbed on the acid-activated montmorillonite K10 (0.067 mg mg−1) and on the illite–smectite (0.086 mg mg−1). These clay minerals do not strongly affect the sorption solution parameters such as pH value and content of cations. Practically no adsorption was observed on the bentonite and vermiculite. Bentonite and vermiculite are subject to stronger interactions with water which cause the increase of pH value of the sorption solution and release of cations to the solution and thus they cause conformational changes of albumin, which was confirmed by circular dichroism measurements. Obtained results were confirmed by infrared spectroscopy and thermal analysis as well. Interaction of studied materials with bovine serum albumin causes the reduction of particle size in the case of all studied clays except vermiculite. Albumin probably attacks the clay structure during the adsorption, which causes the decrease of particle size. The presented work contributes to the knowledge about interaction of bovine serum albumin with clays in the field of influence of physico-chemical behaviour of clays in the solution on the interaction with albumin. Interaction of bovine serum albumin with clays strongly affects the structure of both clay and protein.![]()
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Affiliation(s)
- Martin Mucha
- Department of Chemistry, Faculty of Science, University of Ostrava 30. dubna 22 70103 Ostrava Czech Republic
| | - Roman Maršálek
- Department of Chemistry, Faculty of Science, University of Ostrava 30. dubna 22 70103 Ostrava Czech Republic
| | - Marta Bukáčková
- Department of Chemistry, Faculty of Science, University of Ostrava 30. dubna 22 70103 Ostrava Czech Republic
| | - Gabriela Zelenková
- Department of Chemistry, Faculty of Science, University of Ostrava 30. dubna 22 70103 Ostrava Czech Republic
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Zhao Q, Callister SJ, Thompson AM, Kukkadapu RK, Tfaily MM, Bramer LM, Qafoku NP, Bell SL, Hobbie SE, Seabloom EW, Borer ET, Hofmockel KS. Strong mineralogic control of soil organic matter composition in response to nutrient addition across diverse grassland sites. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 736:137839. [PMID: 32507289 DOI: 10.1016/j.scitotenv.2020.137839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/04/2020] [Accepted: 03/08/2020] [Indexed: 06/11/2023]
Abstract
Soil organic matter (SOM) dynamics are central to soil biogeochemistry and fertility. The retention of SOM is governed initially by interactions with minerals, which mediate the sorption of chemically diverse organic matter (OM) molecules via distinct surface areas and chemical functional group availabilities. Unifying principles of mineral-OM interactions remain elusive because of the multi-layered nature of biochemical-mineral interactions that contribute to soil aggregate formation and the heterogeneous nature of soils among ecosystems. This study sought to understand how soil mineralogy as well as nitrogen (N) enrichment regulate OM composition in grassland soils. Using a multi-site grassland experiment, we demonstrate that the composition of mineral-associated OM depended on the clay content and specific mineral composition in soils across the sites. With increasing abundance of ferrihydrite (Fh) across six different grassland locations, OM in the hydrophobic zone became more enriched in lipid- and protein-like compounds, whereas the kinetic zone OM became more enriched in lignin-like molecules. These relationships suggest that the persistence of various classes of OM in soils may depend on soil iron mineralogy and provide experimental evidence to support conceptual models of zonal mineral-OM associations. Experimental N addition disrupted the accumulation of protein-like molecules in the hydrophobic zone and the positive correlation of lignin-like molecules in the kinetic zone with Fh content, compared to unfertilized soils. These data suggest that mineralogy and clay content together influence the chemical composition not only of mineral-associated OM, but also of soluble compounds within the soil matrix. If these relationships are prevalent over larger spatial and temporal scales, they provide a foundation for understanding SOM cycling and persistence under a variety of environmental contexts.
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Affiliation(s)
- Qian Zhao
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Stephen J Callister
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Allison M Thompson
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Ravi K Kukkadapu
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Malak M Tfaily
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Lisa M Bramer
- National Security Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Nikolla P Qafoku
- Energy & Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Sheryl L Bell
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA
| | - Sarah E Hobbie
- Department of Ecology, Evolution & Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, MN 55108, USA
| | - Eric W Seabloom
- Department of Ecology, Evolution & Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, MN 55108, USA
| | - Elizabeth T Borer
- Department of Ecology, Evolution & Behavior, University of Minnesota, 1479 Gortner Avenue, St. Paul, MN 55108, USA
| | - Kirsten S Hofmockel
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, USA; Department of Ecology, Evolution & Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA 50011, USA.
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Alnaanah SA, Roussel TJ, Ghithan JH, Qatamin AH, Irziqat MA, Telfah H, Liu J, Mendes SB. Electroactive Interface for Enabling Spectroelectrochemical Investigations in Evanescent-Wave Cavity-Ring-Down Spectroscopy. Anal Chem 2020; 92:11288-11296. [PMID: 32689790 DOI: 10.1021/acs.analchem.0c01956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study, we report the development of an electrically active solid-liquid interface for the evanescent-wave cavity-ring-down spectroscopic (EW-CRDS) technique to enable spectroelectrochemical investigations of redox events. Because of a high-quality transparent conductive electrode film of indium tin oxide (ITO) coated on the interface of total internal reflection of the EW-CRDS platform, a cavity ring-down time of about 900 ns was obtained allowing spectroelectrochemical studies at solid-liquid interfaces. As a proof-of-concept on the capabilities of the developed platform, measurements were performed to address the effects of an applied electric potential to the adsorption behavior of the redox protein cytochrome c (Cyt-C) onto different interfaces, namely, bare-ITO, 3-aminopropyl triethoxysilane (APTES), and Cyt-C antibody. For each interface, the adsorption and desorption constants, the surface equilibrium constant, the Gibbs free energy of adsorption, and the surface coverage were optically measured by our electrically active EW-CRDS tool. Optical measurements at a set of constant discrete values of the applied electric potential were acquired for kinetic adsorption analysis. Cyclic voltammetry (CV) scans under synchronous optical readout were performed to study the effects of each molecular interface on the redox process of surface-adsorbed protein species. Overall, the experimental results demonstrate the ability of the electro-active EW-CRDS platform to unambiguously measure electrode-driven redox events of surface-confined molecular species at low submonolayer coverages and at a single diffraction-limited spot. Such capability is expected to open several opportunities for the EW-CRDS technique to investigate a variety of electrochemical phenomena at solid-liquid interfaces.
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Affiliation(s)
- Shadi A Alnaanah
- Department of Physics and Astronomy, University of Louisville, Louisville, Kentucky 40208, United States
| | - Thomas J Roussel
- Department of Bioengineering, University of Louisville, Louisville, Kentucky 40208, United States
| | - Jafar H Ghithan
- Department of Physics and Astronomy, University of Louisville, Louisville, Kentucky 40208, United States
| | - Aymen H Qatamin
- Department of Physics and Astronomy, University of Louisville, Louisville, Kentucky 40208, United States
| | - Mohammed A Irziqat
- Department of Physics and Astronomy, University of Louisville, Louisville, Kentucky 40208, United States
| | - Hamzeh Telfah
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
| | - Jinjun Liu
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
| | - Sergio B Mendes
- Department of Physics and Astronomy, University of Louisville, Louisville, Kentucky 40208, United States
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Çalımlı MH, Demirbaş Ö, Aygün A, Alma MH, Nas MS, Khan A, Asiri AM, Şen F. Equilibrium, Kinetics and Thermodynamics of Bovine Serum Albumin from Carbon Based Materials Obtained from Food Wastes. BIONANOSCIENCE 2019. [DOI: 10.1007/s12668-019-00633-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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8
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Demirbaş Ö, Çalımlı MH, Demirkan B, Alma MH, Nas MS, Khan A, Asiri AM, Şen F. Thermodynamics, Kinetics, and Adsorption Properties of Biomolecules onto Carbon-Based Materials Obtained from Food Wastes. BIONANOSCIENCE 2019. [DOI: 10.1007/s12668-019-00628-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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10
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Kanjanakawinkul W, Medlicott NJ, Rades T, Puttipipatkhachorn S, Pongjanyakul T. Lysozyme-magnesium aluminum silicate microparticles: Molecular interaction, bioactivity and release studies. Int J Biol Macromol 2015; 80:651-8. [PMID: 26193680 DOI: 10.1016/j.ijbiomac.2015.07.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 07/07/2015] [Accepted: 07/10/2015] [Indexed: 11/28/2022]
Abstract
The objectives of this study were to investigate the adsorption behavior of lysozyme (LSZ) onto magnesium aluminum silicate (MAS) at various pHs and to characterize the LSZ-MAS microparticles obtained from the molecular interaction between LSZ and MAS. The results showed that LSZ could be bound onto the MAS layers at different pHs, leading to the formation of LSZ-MAS microparticles. The higher preparation pH permitted greater adsorption affinity but a lower adsorption capacity of LSZ onto MAS. LSZ could interact with MAS via hydrogen bonds and electrostatic forces, resulting in the formation of intercalated nanocomposites. The particle size, %LSZ adsorbed, and LSZ release rate of LSZ-MAS microparticles increased when the LSZ-MAS ratio was increased. The secondary structure of LSZ bound onto the MAS layers in microparticles prepared at various pHs was altered compared with that of native LSZ. Moreover, the LSZ extracted from microparticles prepared at pH 4 showed an obvious change in the tertiary structure, leading to a decrease in the biological activity of the LSZ released. These findings suggested that LSZ can strongly interact with MAS to form microparticles that may potentially be used as delivery systems for sustained protein release.
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Affiliation(s)
| | | | - Thomas Rades
- School of Pharmacy, University of Otago, Dunedin 9054, New Zealand; Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Satit Puttipipatkhachorn
- Department of Manufacturing Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand
| | - Thaned Pongjanyakul
- Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
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Hristova SH, Zhivkov AM. Adsorption of cytochrome c on montmorillonite nanoplates: Protein concentration dependence. J Colloid Interface Sci 2015; 446:252-62. [DOI: 10.1016/j.jcis.2015.01.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 01/05/2015] [Accepted: 01/13/2015] [Indexed: 11/25/2022]
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Assifaoui A, Huault L, Maissiat C, Roullier-Gall C, Jeandet P, Hirschinger J, Raya J, Jaber M, Lambert JF, Cayot P, Gougeon RD, Loupiac C. Structural studies of adsorbed protein (betalactoglobulin) on natural clay (montmorillonite). RSC Adv 2014. [DOI: 10.1039/c4ra11607k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Adsorption of betalactoglobulin on montmorillonite leads to structural changes of the protein accompanied by a partial exfoliation of clay.
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Affiliation(s)
- Ali Assifaoui
- UMR PAM Université de Bourgogne/AgroSup Dijon
- PAPC Team
- 21000 Dijon, France
| | - Lucie Huault
- UMR PAM Université de Bourgogne/AgroSup Dijon
- PAPC Team
- 21000 Dijon, France
| | - Cyrielle Maissiat
- UMR PAM Université de Bourgogne/AgroSup Dijon
- PAPC Team
- 21000 Dijon, France
| | | | - Philippe Jeandet
- Laboratoire de Stress
- Défenses et Reproduction des Plantes
- Université de Reims Champagne-Ardenne
- UFR Sciences Exactes et Naturelles
- Unité de Recherche Vigne et Vins de Champagne – EA 4707
| | - Jérôme Hirschinger
- Institut de Chimie
- UMR 7177 CNRS
- Université de Strasbourg
- 67008 Strasbourg, France
| | - Jésus Raya
- Institut de Chimie
- UMR 7177 CNRS
- Université de Strasbourg
- 67008 Strasbourg, France
| | - Maguy Jaber
- Laboratoire d'Archéologie Moléculaire et Structurale (UMR 8220 CNRS)
- UPMC Université Paris 6
- Paris, France
| | - Jean-François Lambert
- Laboratoire de Réactivité de Surface (UMR 7197 CNRS)
- UPMC Université Paris 6
- 94200 Ivry-sur-Seine, France
| | - Philippe Cayot
- UMR PAM Université de Bourgogne/AgroSup Dijon
- PAPC Team
- 21000 Dijon, France
| | - Régis D. Gougeon
- UMR PAM Université de Bourgogne/AgroSup Dijon
- PAPC Team
- 21000 Dijon, France
| | - Camille Loupiac
- UMR PAM Université de Bourgogne/AgroSup Dijon
- PAPC Team
- 21000 Dijon, France
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13
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Wu Y, Jiang Y, Jiao J, Liu M, Hu F, Griffiths BS, Li H. Adsorption of Trametes versicolor laccase to soil iron and aluminum minerals: enzyme activity, kinetics and stability studies. Colloids Surf B Biointerfaces 2013; 114:342-8. [PMID: 24225344 DOI: 10.1016/j.colsurfb.2013.10.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 09/15/2013] [Accepted: 10/10/2013] [Indexed: 11/27/2022]
Abstract
Laccases play an important role in the degradation of soil phenol or phenol-like substance and can be potentially used in soil remediation through immobilization. Iron and aluminum minerals can adsorb extracellular enzymes in soil environment. In the present study, we investigated the adsorptive interaction of laccase, from the white-rot fungus Trametes versicolor, with soil iron and aluminum minerals and characterized the properties of the enzyme after adsorption to minerals. Results showed that both soil iron and aluminum minerals adsorbed great amount of laccase, independent of the mineral specific surface areas. Adsorbed laccases retained 26-64% of the activity of the free enzyme. Compared to the free laccase, all adsorbed laccases showed higher Km values and lower Vmax values, indicating a reduced enzyme-substrate affinity and a lower rate of substrate conversion in reactions catalyzed by the adsorbed laccase. Adsorbed laccases exhibited increased catalytic activities compared to the free laccase at low pH, implying the suitable application of iron and aluminum mineral-adsorbed T. versicolor laccase in soil bioremediation, especially in acid soils. In terms of the thermal profiles, adsorbed laccases showed decreased thermal stability and higher temperature sensitivity relative to the free laccase. Moreover, adsorption improved the resistance of laccase to proteolysis and extended the lifespan of laccase. Our results implied that adsorbed T. versicolor laccase on soil iron and aluminum minerals had promising potential in soil remediation.
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Affiliation(s)
- Yue Wu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Ying Jiang
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Jiaguo Jiao
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Manqiang Liu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Feng Hu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | | | - Huixin Li
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
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15
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Tomaszewski JE, Madliger M, Pedersen JA, Schwarzenbach RP, Sander M. Adsorption of insecticidal Cry1Ab protein to humic substances. 2. Influence of humic and fulvic acid charge and polarity characteristics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:9932-9940. [PMID: 22862550 DOI: 10.1021/es302248u] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Assessing the fate and potential risks of transgenic Cry proteins in soils requires understanding of Cry protein adsorption to soil particles. The companion paper provided evidence that patch-controlled electrostatic attraction (PCEA) and the hydrophobic effect contributed to Cry1Ab protein adsorption to an apolar humic acid (HA). Here, we further assess the relative importance of these contributions by comparing Cry1Ab adsorption to seven humic substances varying in polarity and charge, at different solution pH and ionic strength, I. Cry1Ab adsorption to relatively apolar HAs at I = 50 mM exhibited rapid initial rates, was extensive, and was only partially reversible at pH 5-8, whereas adsorption to more polar fulvic acids was weak and reversible or absent at pH >6. The decrease in adsorption with increasing HS polarity at all tested pH strongly supports a large contribution from the hydrophobic effect to adsorption, particularly at I = 50 mM when PCEA was effectively screened. Using insect bioassays, we further show that Cry1Ab adsorbed to a selected HA retained full insecticidal activity. Our results highlight the need to consider adsorption to soil organic matter in models that assess the fate of Cry proteins in soils.
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Affiliation(s)
- Jeanne E Tomaszewski
- Swiss Federal Institute of Technology, ETH Zurich, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Zurich, Switzerland
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18
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Adsorption on montmorillonite prevents oligomerization of Bt Cry1Aa toxin. J Colloid Interface Sci 2011; 356:718-25. [DOI: 10.1016/j.jcis.2011.01.064] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 01/17/2011] [Accepted: 01/20/2011] [Indexed: 11/30/2022]
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Smith CB, Booth CJ, Pedersen JA. Fate of prions in soil: a review. JOURNAL OF ENVIRONMENTAL QUALITY 2011; 40:449-461. [PMID: 21520752 PMCID: PMC3160281 DOI: 10.2134/jeq2010.0412] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Prions are the etiological agents of transmissible spongiform encephalopathies (TSSEs), a class of fatal neurodegenerative diseases affecting humans and other mammals. The pathogenic prion protein is a misfolded form of the host-encoded prion protein and represents the predominant, if not sole, component of the infectious agent. Environmental routes of TSE transmission areimplicated in epizootics of sheep scrapie and chronic wasting disease (CWD) of deer, elk, and moose. Soil represents a plausible environmental reservoir of scrapie and CWD agents, which can persist in the environment for years. Attachment to soil particles likely influences the persistence and infectivity of prions in the environment. Effective methods to inactivate TSE agents in soil are currently lacking, and the effects of natural degradation mechanisms on TSE infectivity are largely unknown. An improved understanding of the processes affecting the mobility, persistence, and bioaviailability of prions in soil is needed for the management of TSE-contaminated environments.
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Affiliation(s)
- Christen B. Smith
- Environmental Chemistry and Technology Program, Univ. of Wisconsin, 1525 Observatory Dr., Madison, WI 53706
| | - Clarissa J. Booth
- Molecular and Environmental Toxicology Center, Univ. of Wisconsin, 1525 Observatory Dr., Madison, WI 53706
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Ralla K, Sohling U, Riechers D, Kasper C, Ruf F, Scheper T. Adsorption and separation of proteins by a smectitic clay mineral. Bioprocess Biosyst Eng 2010; 33:847-61. [DOI: 10.1007/s00449-010-0408-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 01/12/2010] [Indexed: 10/19/2022]
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21
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Wicke D, Reemtsma T. Mobilization of hydrophobic contaminants from soils by enzymatic depolymerization of soil organic matter. CHEMOSPHERE 2010; 78:996-1003. [PMID: 20045174 DOI: 10.1016/j.chemosphere.2009.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 12/01/2009] [Accepted: 12/04/2009] [Indexed: 05/28/2023]
Abstract
The effect of hydrolytic exoenzymes on the release of hydrophobic organic contaminants (HOC) from two different surface soils was studied in laboratory batch experiments. Incubation of the soils with cellulase with an activity fivefold above the inherent soil activity enhanced the release of hydrophobic contaminants (polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and hydroxylated PCB) by 40-200%. Xylanase and invertase did not show measurable effects at comparable relative activity levels. This suggests that cellulose substructures are important for the retention of HOC in soil organic matter (SOM). Hydrolytic exoenzymes, and the microorganisms that release them, contribute to the mobilization of HOC from soil, by shifting the sorption equilibrium in the course of SOM transformation into dissolved organic matter or by facilitating HOC diffusion as a consequence of reduced rigidity of SOM. We conclude that not only biodegradation but also sorption and desorption of HOC in soil can be influenced by (micro-) biology and the factors that determine its activity.
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Affiliation(s)
- Daniel Wicke
- Department of Water Quality Control, Technical University Berlin, Sekr KF 4, Strasse des 17, Juni 135, 10623 Berlin, Germany
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Miao S, Leeman H, De Feyter S, Schoonheydt RA. Facile preparation of Langmuir–Blodgett films of water-soluble proteins and hybrid protein–clay films. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b913659b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Demanèche S, Chapel JP, Monrozier LJ, Quiquampoix H. Dissimilar pH-dependent adsorption features of bovine serum albumin and α-chymotrypsin on mica probed by AFM. Colloids Surf B Biointerfaces 2009; 70:226-31. [DOI: 10.1016/j.colsurfb.2008.12.036] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 12/19/2008] [Accepted: 12/19/2008] [Indexed: 11/27/2022]
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Cooke CM, Rodger J, Smith A, Fernie K, Shaw G, Somerville RA. Fate of prions in soil: detergent extraction of PrP from soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:811-7. [PMID: 17328187 DOI: 10.1021/es0618189] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The transmissible spongiform encephalopathies (TSEs) are caused by infectious agents whose structures have not been fully characterized but include abnormal forms of the host protein PrP, designated PrP(Sc), which are deposited in infected tissues. The transmission routes of scrapie and chronic wasting disease (CWD) seem to include environmental spread in their epidemiology, yet the fate of TSE agents in the environment is poorly understood. There are concerns that, for example, buried carcasses may remain a potential reservoir of infectivity for many years. Experimental determination of the environmental fate requires methods for assessing binding/elution of TSE infectivity, or its surrogate marker PrP(Sc), to and from materials with which it might interact. We report a method using Sarkosyl for the extraction of murine PrP(Sc), and its application to soils containing recombinant ovine PrP (recPrP). Elution properties suggest that PrP binds strongly to one or more soil components. Elution from a clay soil also required proteinase K digestion, suggesting that in the clay soil binding occurs via the N-terminal of PrP to a component that is absent from the sandy soils tested.
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Affiliation(s)
- Cindy M Cooke
- Centre for Environmental Policy, Imperial College London, Silwood Park, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK.
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Johnson CJ, Phillips KE, Schramm PT, McKenzie D, Aiken JM, Pedersen JA. Prions adhere to soil minerals and remain infectious. PLoS Pathog 2006; 2:e32. [PMID: 16617377 PMCID: PMC1435987 DOI: 10.1371/journal.ppat.0020032] [Citation(s) in RCA: 189] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Accepted: 03/08/2006] [Indexed: 11/30/2022] Open
Abstract
An unidentified environmental reservoir of infectivity contributes to the natural transmission of prion diseases (transmissible spongiform encephalopathies [TSEs]) in sheep, deer, and elk. Prion infectivity may enter soil environments via shedding from diseased animals and decomposition of infected carcasses. Burial of TSE-infected cattle, sheep, and deer as a means of disposal has resulted in unintentional introduction of prions into subsurface environments. We examined the potential for soil to serve as a TSE reservoir by studying the interaction of the disease-associated prion protein (PrPSc) with common soil minerals. In this study, we demonstrated substantial PrPSc adsorption to two clay minerals, quartz, and four whole soil samples. We quantified the PrPSc-binding capacities of each mineral. Furthermore, we observed that PrPSc desorbed from montmorillonite clay was cleaved at an N-terminal site and the interaction between PrPSc and Mte was strong, making desorption of the protein difficult. Despite cleavage and avid binding, PrPSc bound to Mte remained infectious. Results from our study suggest that PrPSc released into soil environments may be preserved in a bioavailable form, perpetuating prion disease epizootics and exposing other species to the infectious agent. Transmissible spongiform encephalopathies (TSEs) are a group of incurable diseases likely caused by a misfolded form of the prion protein (PrPSc). TSEs include scrapie in sheep, bovine spongiform encephalopathy (“mad cow” disease) in cattle, chronic wasting disease (CWD) in deer and elk, and Creutzfeldt-Jakob disease in humans. Scrapie and CWD are unique among TSEs because they can be transmitted between animals, and the disease agents appear to persist in environments previously inhabited by infected animals. Soil has been hypothesized to act as a reservoir of infectivity, because PrPSc likely enters soil environments through urinary or alimentary shedding and decomposition of infected animals. In this manuscript, the authors test the potential for soil to serve as a reservoir for PrPSc and TSE infectivity. They demonstrate that PrPSc binds to a variety of soil minerals and to whole soils. They also quantitate the levels of protein binding to three common soil minerals and show that the interaction of PrPSc with montmorillonite, a common clay mineral, is remarkably strong. PrPSc bound to Mte remained infectious to laboratory animals, suggesting that soil can serve as a reservoir of TSE infectivity.
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Affiliation(s)
- Christopher J Johnson
- Program in Cellular and Molecular Biology, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Kristen E Phillips
- Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Peter T Schramm
- Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Debbie McKenzie
- Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Judd M Aiken
- Program in Cellular and Molecular Biology, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America
| | - Joel A Pedersen
- Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- Department of Soil Science, University of Wisconsin Madison, Madison, Wisconsin, United States of America
- * To whom correspondence should be addressed. E-mail:
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Lagaly G, Ogawa M, Dékány I. Chapter 7.3 Clay Mineral Organic Interactions. DEVELOPMENTS IN CLAY SCIENCE 2006. [DOI: 10.1016/s1572-4352(05)01010-x] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Zhang H, Bremmell KE, Smart RSC. Direct measurement of interactions between adsorbed vitronectin layers: The influence of ionic strength and pH. J Biomed Mater Res A 2005; 74:59-68. [PMID: 15909285 DOI: 10.1002/jbm.a.30364] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Vitronectin (Vn) is an adhesive protein in the plasma serum and plays an important role in cell attachment, spreading, and proliferation. The interactions between protein bovine vitronectin layers adsorbed onto a silica probe and a mica surface have been investigated with the use of atomic force microscopy (AFM). Adsorption of vitronectin was confirmed by XPS surface analysis. The force-separation curves and pull-off forces were measured as a function of ionic strength and solution pH. The pull-off force (adhesion force) decreased as the salt concentration increased, which suggests that some binding domains of this protein may associate with the ionic species and reduce its binding ability. Discrete jumps, or discontinuities, in the separation force curve were observed to extend to a maximum of 300 nm, evidence that the protein molecules bridge between the surfaces. As a function of pH, the adhesion force on separation of the protein-coated surfaces showed a maximum at pH 5 (i.e.p. of vitronectin), decreasing in magnitude at lower and higher pH values. At pH 5, the approaching curves illustrated a jump-in force; whereas for pH values away from 5, the approaching force curves were repulsive. Correlation of the interaction forces with Vn conformational changes in different pH environments, directly visualized with the use of AFM imaging, was developed. In its i.e.p. region, the Vn molecular conformation appeared to be dense and compact. Significantly, at wounds/injured sites the pH is low (approximately 5) which this study discovered to facilitate adsorption and formation of vitronectin aggregates, known to trigger their subsequent biological functions.
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Affiliation(s)
- Hailong Zhang
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia
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Vasina EN, Déjardin P. Adsorption of alpha-chymotrypsin onto mica in laminar flow conditions. Adsorption kinetic constant as a function of tris buffer concentration at pH 8.6. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:8699-8706. [PMID: 15379495 DOI: 10.1021/la0490588] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We examined the adsorption kinetics of alpha-chymotrypsin (pH 8.6, 10(-2) to 0.5 M Tris buffer) on muscovite mica in conditions of laminar flow through a slit. The range of buffer concentrations is between two limits: (i) no adsorption in 1 M Tris and (ii) no desorption in 10(-3) M Tris. Studying the dependence of adsorption kinetics on the wall shear rate leads to the determination of the interfacial adsorption kinetic constant ka and the diffusion coefficient. The obtained value for the diffusion coefficient is close to the one expected from the molecular size of alpha-chymotrypsin. The interfacial adsorption kinetic constant of alpha-chymotrypsin decreases when ionic strength increases, while the initial desorption constant (over a part of all the adsorbed population) shows the contrary. Although alpha-chymotrypsin is almost at its isoelectric point, the effect of ionic strength on the adsorption kinetics suggests the importance of electrostatic interactions between the protein and mica. We observed an increase in the adsorption rate, at a surface coverage near 0.14 microg cm(-2), for adsorption in 10(-2) M Tris and the low wall shear rates (<300 s(-1)). This change in the adsorption rate suggests a structural transition, that we assume again to be due to electrostatic interactions, but between proteins. The large dipole moment of the protein may induce this transition, illustrated here by the ferroelectric/antiferroelectric pattern. The variation of the zeta potential with interfacial concentration seems to be in agreement with such a model.
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Affiliation(s)
- Elena N Vasina
- European Membrane Institute, UMR 5635 (CNRS, ENSCM, UMII), Université Montpellier II, CC047, 2 Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France
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Gougeon R, Soulard M, Reinholdt M, Miehé-Brendlé J, Chézeau JM, Dred R, Marchal R, Jeandet P. Polypeptide Adsorption on a Synthetic Montmorillonite: A Combined Solid-State NMR Spectroscopy, X-ray Diffraction, Thermal Analysis and N2 Adsorption Study. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200390177] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Vasina EN, Déjardin P. Kinetics of adsorption, desorption, and exchange of alpha-chymotrypsin and lysozyme on poly(ethyleneterephthalate) tracked film and track-etched membrane. Biomacromolecules 2003; 4:304-13. [PMID: 12625725 DOI: 10.1021/bm025668f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adsorption kinetics of (125)I-radiolabeled alpha-chymotrypsin at pH 8.6 was studied in a laminar regime between two walls of poly(ethyleneterephthalate) tracked films and membranes. Adsorption kinetics in the presence of solution (10 microg/mL), desorption by rinsing with buffer, and the following exchange of proteins by flowing unlabeled solution were measured. At pH 8.6, alpha-chymotrypsin is almost neutral and can be mostly removed from the film surface, contrary to positive lysozyme adsorbed at pH 7.4. Results suggest that alpha-chymotrypsin is irreversibly adsorbed in pores, while desorption and exchange occur on membrane flat faces. A method is proposed to determine adsorption kinetics in the pores. Kinetics of desorption and exchange of alpha-chymotrypsin from the film surface can be described by stretched exponential functions in the examined time domain with the same exponent, beta approximately 0.62, which does not depend also on the former adsorption duration. However, the mean residence time at the interface is about 2.5 times greater in the presence of only the buffer than that in the presence of solution. This effect could be explained by a fast exchange at the arrival of unlabeled solution for a part of the adsorbed population.
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Affiliation(s)
- Elena N Vasina
- Department of Molecular Physics, Kazan State University, Kremlevskaya St 18, Russia
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31
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Criquet S. Measurement and characterization of cellulase activity in sclerophyllous forest litter. J Microbiol Methods 2002; 50:165-73. [PMID: 11997167 DOI: 10.1016/s0167-7012(02)00028-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Cellulases are enzymatic proteins which hydrolyze cellulose polymers to smaller oligosaccharides, cellobiose and glucose. They consist in three major types of enzymes: endoglucanases (EC 3.2.1.4), cellobiohydrolases (EC 3.2.1.91) and beta-glucosidases (EC 3.2.1.21) which play an essential role in carbon turnover of forest ecosystem. The aim of this study was firstly to determine the parameters (i.e. buffer type, pH, temperature, quantity of litter, incubation time and reagent type) which affect the measurement of cellulase activity in a sclerophyllous forest litter, and secondly to compare two methods for measuring cellulase activity: a direct method and an extraction method. In the direct method, the litter was directly incubated with a buffered solution containing the enzyme substrate, whereas in the extraction method, the cellulases were firstly extracted before measuring their activity. The results were compared with other studies about soil cellulase activity, and it appeared that several parameters (buffer type, pH, temperature and sample quantity) which influence the measurement of cellulase activity differ according to whether a soil or a litter is considered. Concerning the procedure used for the measurement of cellulase activity, results showed that the activity values were higher when using an extraction procedure than when using a direct procedure. The extraction procedure, combined with a concentration stage of the extract, also allowed electrophoretic analysis (PAGE) of the cellulases extracted from the litter. The electrophoretic pattern revealed two cellulase isoenzymes which may be related to the occurrence of two pH-activity peaks of these enzymes when citrate buffer was used for the measurement of cellulase activity in the litter.
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Affiliation(s)
- Stéven Criquet
- Institut Méditerranéen d'Ecologie et de Paléoécologie, UMR CNRS 6116, Laboratoire de Microbiologie, Service 452, Faculté des Sciences et Techniques de Saint-Jérôme, 13397 Cédex 20, Marseille, France.
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32
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Bajpai AK, Sachdeva R. Study on the adsorption of hemoglobin onto bentonite clay surfaces. J Appl Polym Sci 2002. [DOI: 10.1002/app.10698] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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33
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Adsorption of the insecticidal toxin from Bacillus thuringiensis subspecies Tenebrionis to clay fractions of tropical soils. DEVELOPMENTS IN SOIL SCIENCE 2002. [DOI: 10.1016/s0166-2481(02)80008-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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A simple method for purifying glycosidases: alpha-l-rhamnopyranosidase from Aspergillus niger to increase the aroma of Moscato wine. Enzyme Microb Technol 2000; 27:522-530. [PMID: 10978775 DOI: 10.1016/s0141-0229(00)00236-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
alpha-L-rhamnopyranosidase (Rha, EC 3.2.1.40) is an enzyme of considerable importance in food technology for increasing the aroma of wines, musts, fruit juices and other alcoholic beverages. The aim of this research is to study the purification of Rha contained in a commercial preparation already used in the winemaking industry. With the procedure adopted, Rha recovery values were excellent (ca 85%), comparable with those we found in a previous paper on the purification of other glycosidases such beta-D-glucopyranosidase (betaG) and alpha-L-arabinofuranosidase (Ara) [1]. The Rha purification value (4.3) and drastic reduction in brown compounds (DeltaAbs 95%) represent other strengths of the proposed method that has proved inexpensive and simple to apply. In addition, purified Rha has shown itself to be more stable than other glycosidases. This had optimum effect at pH 4, while optimum temperature was 70 degrees C, greater than that found for other glycosidases. The purified enzyme was characterized in terms of the kinetic parameters K(m) (1.40 mM) and V(max) (1.30 U mg(-1) of protein) and subsequently used to increase aroma a model wine solution containing aromatic precursors extracted from the skins of Moscato grapes, with an increase in the content of total terpenols of ca 2.3 times.
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Servagent-Noinville S, Revault M, Quiquampoix H, Baron M. Conformational Changes of Bovine Serum Albumin Induced by Adsorption on Different Clay Surfaces: FTIR Analysis. J Colloid Interface Sci 2000; 221:273-283. [PMID: 10631031 DOI: 10.1006/jcis.1999.6576] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Interactions between proteins and clays perturb biological activity in ecosystems, particularly soil extracellular enzyme activity. The pH dependence of hydrophobic, hydrophilic, and electrostatic interactions on the adsorption of bovine serum albumin (BSA) is studied. BSA secondary structures and hydration are revealed from computation of the Amide I and II FTIR absorption profiles. The influence of ionization of Asp, Glu, and His side chains on the adsorption processes is deduced from correlation between p(2)H dependent carboxylic/carboxylate ratio and Amide band profiles. We quantify p(2)H dependent internal and external structural unfolding for BSA adsorbed on montmorillonite, which is an electronegative phyllosilicate. Adsorption on talc, a hydrophobic surface, is less denaturing. The results emphasize the importance of electrostatic interactions in both adsorption processes. In the first case, charged side chains directly influence BSA adsorption that generate the structural transition. In the second case, the forces that attract hydrophobic side chains toward the protein-clay interface are large enough to distort peripheral amphiphilic helical domains. The resulting local unfolding displaces enough internal ionized side chains to prevent them from establishing salt bridges as for BSA native structure in solution. On montmorillonite, a particular feature is a higher protonation of the Asp and Glu side chains of the adsorbed BSA than in solution, which decreases coulombic repulsion. Copyright 2000 Academic Press.
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Affiliation(s)
- S Servagent-Noinville
- Laboratoire de Dynamique, Interactions et Réactivité, CNRS-Université Paris 6, 2 rue Henry Dunant, Thiais, 94320, France
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Baron MH, Revault M, Servagent-Noinville S, Abadie J, Quiquampoix H. Chymotrypsin Adsorption on Montmorillonite: Enzymatic Activity and Kinetic FTIR Structural Analysis. J Colloid Interface Sci 1999; 214:319-332. [PMID: 10339371 DOI: 10.1006/jcis.1999.6189] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Soils have a large solid surface area and high adsorptive capacities. To determine if structural and solvation changes induced by adsorption on clays are related to changes in enzyme activity, alpha-chymotrypsin adsorbed on a phyllosilicate with an electronegative surface (montmorillonite) has been studied by transmission FTIR spectroscopy. A comparison of the pH-dependent structural changes for the solution and adsorbed states probes the electrostatic origin of the adsorption. In the pD range 4.5-10, adsorption only perturbs some peripheral domains of the protein compared to the solution. Secondary structure unfolding affects about 15-20 peptide units. Parts of these domains become hydrated and others entail some self-association. However, the inactivation of the catalytic activity of the adsorbed enzyme in the 5-7 pD range is due less to these structural changes than to steric hindrance when three essential imino/amino functions, located close to the entrance of the catalytic cavity (His-40 and -57 residues and Ala-149 end chain residue), are oriented toward the negatively charged mineral surface. When these functions lose their positive charge, the orientation of the adsorbed enzyme is changed and an activity similar to that in solution at equivalent pH is recovered. This result is of fundamental interest in all fields of research where enzymatic activity is monitored using reversible adsorption procedures. Copyright 1999 Academic Press.
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Affiliation(s)
- MH Baron
- UPR 1580 CNRS, Université Paris VI, 2 rue Henri Dunant, Thiais, 94320, France
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