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Pellenz L, de Oliveira CRS, da Silva Júnior AH, da Silva LJS, da Silva L, Ulson de Souza AA, de Souza SMDAGU, Borba FH, da Silva A. A comprehensive guide for characterization of adsorbent materials. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2022.122435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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2
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Krevert CS, Gunkel L, Haese C, Hunger J. Ion-specific binding of cations to the carboxylate and of anions to the amide of alanylalanine. Commun Chem 2022; 5:173. [PMID: 36697920 PMCID: PMC9814750 DOI: 10.1038/s42004-022-00789-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Studies of ion-specific effects on oligopeptides have aided our understanding of Hofmeister effects on proteins, yet the use of different model peptides and different experimental sensitivities have led to conflicting conclusions. To resolve these controversies, we study a small model peptide, L-Alanyl-L-alanine (2Ala), carrying all fundamental chemical protein motifs: C-terminus, amide bond, and N-terminus. We elucidate the effect of GdmCl, LiCl, KCl, KI, and KSCN by combining dielectric relaxation, nuclear magnetic resonance (1H-NMR), and (two-dimensional) infrared spectroscopy. Our dielectric results show that all ions reduce the rotational mobility of 2Ala, yet the magnitude of the reduction is larger for denaturing cations than for anions. The NMR chemical shifts of the amide group are particularly sensitive to denaturing anions, indicative of anion-amide interactions. Infrared experiments reveal that LiCl alters the spectral homogeneity and dynamics of the carboxylate, but not the amide group. Interaction of LiCl with the negatively charged pole of 2Ala, the COO- group, can explain the marked cationic effect on dipolar rotation, while interaction of anions between the poles, at the amide, only weakly perturbs dipolar dynamics. As such, our results provide a unifying view on ions' preferential interaction sites at 2Ala and help rationalize Hofmeister effects on proteins.
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Affiliation(s)
- Carola Sophie Krevert
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Lucas Gunkel
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Constantin Haese
- grid.419547.a0000 0001 1010 1663Department of Molecular Electronics, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Johannes Hunger
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Kasza G, Stumphauser T, Bisztrán M, Szarka G, Hegedüs I, Nagy E, Iván B. Thermoresponsive Poly( N, N-diethylacrylamide- co-glycidyl methacrylate) Copolymers and Its Catalytically Active α-Chymotrypsin Bioconjugate with Enhanced Enzyme Stability. Polymers (Basel) 2021; 13:987. [PMID: 33806995 PMCID: PMC8004754 DOI: 10.3390/polym13060987] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/19/2021] [Accepted: 03/20/2021] [Indexed: 12/11/2022] Open
Abstract
Responsive (smart, intelligent, adaptive) polymers have been widely explored for a variety of advanced applications in recent years. The thermoresponsive poly(N,N-diethylacrylamide) (PDEAAm), which has a better biocompatibility than the widely investigated poly(N,N-isopropylacrylamide), has gained increased interest in recent years. In this paper, the successful synthesis, characterization, and bioconjugation of a novel thermoresponsive copolymer, poly(N,N-diethylacrylamide-co-glycidyl methacrylate) (P(DEAAm-co-GMA)), obtained by free radical copolymerization with various comonomer contents and monomer/initiator ratios are reported. It was found that all the investigated copolymers possess LCST-type thermoresponsive behavior with small extent of hysteresis, and the critical solution temperatures (CST), i.e., the cloud and clearing points, decrease linearly with increasing GMA content of these copolymers. The P(DEAAm-co-GMA) copolymer with pendant epoxy groups was found to conjugate efficiently with α-chymotrypsin in a direct, one-step reaction, leading to enzyme-polymer nanoparticle (EPNP) with average size of 56.9 nm. This EPNP also shows reversible thermoresponsive behavior with somewhat higher critical solution temperature than that of the unreacted P(DEAAm-co-GMA). Although the catalytic activity of the enzyme-polymer nanoconjugate is lower than that of the native enzyme, the results of the enzyme activity investigations prove that the pH and thermal stability of the enzyme is significantly enhanced by conjugation the with P(DEAAm-co-GMA) copolymer.
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Affiliation(s)
- György Kasza
- Polymer Chemistry Research Group, Institute of Materials and Environment Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary; (T.S.); (M.B.); (G.S.)
| | - Tímea Stumphauser
- Polymer Chemistry Research Group, Institute of Materials and Environment Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary; (T.S.); (M.B.); (G.S.)
| | - Márk Bisztrán
- Polymer Chemistry Research Group, Institute of Materials and Environment Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary; (T.S.); (M.B.); (G.S.)
| | - Györgyi Szarka
- Polymer Chemistry Research Group, Institute of Materials and Environment Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary; (T.S.); (M.B.); (G.S.)
| | - Imre Hegedüs
- Chemical and Biochemical Procedures Laboratory, Institute of Biomolecular and Chemical Engineering, Faculty of Engineering, University of Pannonia, Egyetem u. 10, H-8200 Veszprém, Hungary; (I.H.); (E.N.)
- Department of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó u. 37–47, H-1094 Budapest, Hungary
| | - Endre Nagy
- Chemical and Biochemical Procedures Laboratory, Institute of Biomolecular and Chemical Engineering, Faculty of Engineering, University of Pannonia, Egyetem u. 10, H-8200 Veszprém, Hungary; (I.H.); (E.N.)
| | - Béla Iván
- Polymer Chemistry Research Group, Institute of Materials and Environment Chemistry, Research Centre for Natural Sciences, Magyar tudósok körútja 2., H-1117 Budapest, Hungary; (T.S.); (M.B.); (G.S.)
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Biocatalytic characterization of free and immobilized laccase from Trametes versicolor in its activation zone. Int J Biol Macromol 2019; 128:681-691. [DOI: 10.1016/j.ijbiomac.2019.01.199] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 12/14/2022]
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Bechekh K, Ghaouar N. Rheoviscosimetric Study of PEG35000 and PEG6000 at pH 7 and pH 9: Conformational Transitions and Unperturbed Dimensions. POLYMER SCIENCE SERIES A 2018. [DOI: 10.1134/s0965545x18050036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Loria KG, Aragón JC, Torregiani SM, Pilosof AM, Farías ME. Flow properties of caseinomacropeptide aqueous solutions: Effect of particle size distribution, concentration, pH and temperature. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2018.03.050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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7
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Ghaouar N. Comments on the analogy by adaptation of formulas between the viscosity and the electrical conductivity. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2017.12.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Saoudi O, Ghaouar N, Ben Salah S, Othman T. Denaturation process of laccase in various media by refractive index measurements. Biochem Biophys Rep 2017; 11:19-26. [PMID: 28955763 PMCID: PMC5614694 DOI: 10.1016/j.bbrep.2017.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 01/24/2017] [Accepted: 05/25/2017] [Indexed: 11/05/2022] Open
Abstract
In this work, we are interested in the denaturation process of a laccase from Tramates versicolor via the determination of the refractive index, the refractive index increment and the specific volume in various media. The measurements were carried out using an Abbe refractometer. We have shown that the refractive index increment values obtained from the slope of the variation of the refractive index vs. Concentration are outside the range refractive index increments of proteins. To correct the results, we have followed the theoretical predictions based on the knowledge of the protein refractive index from its amino acids composition. The denaturation process was studied by calculating the specific volume variation where its determination was related to the Gladstone-Dale and the Lorentz-Lorentz models. Refractive index measurements to follow the denaturation process in various medium. The denaturation process was studied by using the Gladstone-Dale and the Lorentz-Lorentz models. [Morph][F] denatures laccase faster than [pyrr][F].
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Affiliation(s)
- O Saoudi
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia
| | - N Ghaouar
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia.,Université de Carthage, Institut National des Sciences Appliquées et de Technologie, Centre Urbain Nord, BP. 676, Tunis, Tunisia
| | - S Ben Salah
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia
| | - T Othman
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia
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Saoudi O, Ghaouar N, Othman T. Fluorescence study of laccase from Trametes versicolor under the effects of pH, chemical denaturants and ionic liquids. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.11.050] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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10
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Bey H, Gtari W, Aschi A, Othman T. Structure and properties of native and unfolded lysing enzyme from T. harzianum: Chemical and pH denaturation. Int J Biol Macromol 2016; 92:860-866. [DOI: 10.1016/j.ijbiomac.2016.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/12/2016] [Accepted: 08/01/2016] [Indexed: 10/21/2022]
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12
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Rather GM, Mukherjee J, Halling PJ, Gupta MN. Activation of alpha chymotrypsin by three phase partitioning is accompanied by aggregation. PLoS One 2012; 7:e49241. [PMID: 23239966 PMCID: PMC3519768 DOI: 10.1371/journal.pone.0049241] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 10/05/2012] [Indexed: 11/18/2022] Open
Abstract
Precipitation of alpha chymotrypsin in the simultaneous presence of ammonium sulphate and t-butanol (three phase partitioning) resulted in preparations which showed self aggregation of the enzyme molecules. Precipitation with increasing amounts of ammonium sulphate led to increasing size of aggregates. While light scattering estimated the hydrodynamic diameter of these aggregates in the range of 242-1124 nm; Nanoparticle tracking analysis (NTA) gave the value as 130-462 nm. Scanning electron microscopy and gel filtration on Sephadex G-200 showed extensive aggregation in these preparations. Transmission electron microscopy showed that the aggregates had irregular shapes. All the aggregates had about 3× higher catalytic activity than the native enzyme. These aggregates did not differ in λ(max) of fluorescence emission which was around 340 nm. However, all the aggregates showed higher fluorescence emission intensity. Far-UV and near-UV circular dichroism also showed no significant structural changes as compared to the native molecule. Interestingly, HPLC gel filtration (on a hydroxylated silica column) gave 14 nm as the diameter for all preparations. Light scattering of preparations in the presence of 10% ethylene glycol also dissociated the aggregates to monomers of 14 nm. Both these results indicated that hydrophobic interactions were the driving force behind this aggregation. These results indicate: (1) Even without any major structural change, three phase partitioning led to protein molecules becoming highly prone to aggregation. (2) Different methods gave widely different estimates of sizes of aggregates. It was however possible to reconcile the data obtained with various approaches. (3) The nature of the gel filtration column is crucial and use of this technique for refolding and studying aggregation needs a rethink.
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Affiliation(s)
- Gulam Mohmad Rather
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Joyeeta Mukherjee
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Peter James Halling
- Department of Pure and Applied Chemistry, University of Strathclyde, Scotland, United Kingdom
| | - Munishwar Nath Gupta
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
- * E-mail:
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Peng F, Wang Y, Sun L, Liu Y, Hu T, Zhang G, Ma G, Su Z. PEGylation of Proteins in Organic Solution: A Case Study for Interferon beta-1b. Bioconjug Chem 2012; 23:1812-20. [DOI: 10.1021/bc300081f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fei Peng
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
- Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yinjue Wang
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Lijing Sun
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Yongdong Liu
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Tao Hu
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Guifeng Zhang
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Guanghui Ma
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhiguo Su
- National Key Laboratory of Biochemical
Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
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Kumar A, Venkatesu P. Overview of the stability of α-chymotrypsin in different solvent media. Chem Rev 2012; 112:4283-307. [PMID: 22506806 DOI: 10.1021/cr2003773] [Citation(s) in RCA: 176] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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