1
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Feoli A, Sarno G, Castellano S, Sbardella G. DMSO-Related Effects on Ligand-Binding Properties of Lysine Methyltransferases G9a and SETD8. Chembiochem 2024; 25:e202300809. [PMID: 38205880 DOI: 10.1002/cbic.202300809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/12/2024]
Abstract
Being the standard solvent for preparing stock solutions of compounds for drug discovery, DMSO is always present in assay buffers in concentrations ranging from 0.1 % to 5 % (v/v). Even at the lowest concentrations, DMSO-containing solutions can have significant effects on individual proteins and possible pitfalls cannot be eliminated. Herein, we used two protein systems, the lysine methyltransferases G9a/KMT1 C and SETD8/KMT5 A, to study the effects of DMSO on protein stability and on the binding of the corresponding inhibitors, using different biophysical methods such as nano Differential Scanning Fluorimetry (nanoDSF), Differential Scanning Fluorimetry (DSF), microscale thermophoresis (MST), and surface plasmon resonance (SPR), all widely used in drug discovery screening campaigns. We demonstrated that the effects of DMSO are protein- and technique-dependent and cannot be predicted or extrapolated on the basis of previous studies using different proteins and/or different assays. Moreover, we showed that the application of orthogonal biophysical methods can lead to different binding affinity data, thus confirming the importance of using at least two different orthogonal assays in screening campaigns. This variability should be taken into account in the selection and characterization of hit compounds, in order to avoid data misinterpretation.
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Affiliation(s)
- Alessandra Feoli
- Epigenetic Med Chem Lab, Department of Pharmacy, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Giuliana Sarno
- Epigenetic Med Chem Lab, Department of Pharmacy, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
- PhD Program in Drug Discovery and Development, University of Salerno, via Giovanni Paolo II 132, I-84084, Fisciano, SA, Italy
| | - Sabrina Castellano
- Epigenetic Med Chem Lab, Department of Pharmacy, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
| | - Gianluca Sbardella
- Epigenetic Med Chem Lab, Department of Pharmacy, University of Salerno, via Giovanni Paolo II 132, 84084, Fisciano, SA, Italy
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2
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Sugahara G, Ishida Y, Lee JJ, Li M, Tanaka Y, Eoh H, Higuchi Y, Saito T. Long-term cell fate and functional maintenance of human hepatocyte through stepwise culture configuration. FASEB J 2023; 37:e22750. [PMID: 36607308 PMCID: PMC9830592 DOI: 10.1096/fj.202201292rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 01/07/2023]
Abstract
Human hepatocyte culture system represents by far the most physiologically relevant model for our understanding of liver biology and diseases; however, its versatility has been limited due to the rapid and progressive loss of genuine characteristics, indicating the inadequacy of in vitro milieu for fate maintenance. This study, therefore, is designed to define environmental requirements necessary to sustain the homeostasis of terminally differentiated hepatocytes. Our study reveals that the supplementation of dimethyl sulfoxide (DMSO) is indispensable in mitigating fate deterioration and promoting adaptation to the in vitro environment, resulting in the restoration of tight cell-cell contact, cellular architecture, and polarity. The morphological recovery was overall accompanied by the restoration of hepatocyte marker gene expression, highlighting the interdependence between the cellular architecture and the maintenance of cell fate. However, beyond the recovery phase culture, DMSO supplementation is deemed detrimental due to the potent inhibitory effect on a multitude of hepatocyte functionalities while its withdrawal results in the loss of cell fate. In search of DMSO substitute, our screening of organic substances led to the identification of dimethyl sulfone (DMSO2), which supports the long-term maintenance of proper morphology, marker gene expression, and hepatocytic functions. Moreover, hepatocytes maintained DMSO2 exhibited clinically relevant toxicity in response to prolonged exposure to xenobiotics as well as alcohol. These observations suggest that the stepwise culture configuration consisting of the consecutive supplementation of DMSO and DMSO2 confers the microenvironment essential for the fate and functional maintenance of terminally differentiated human hepatocytes.
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Affiliation(s)
- Go Sugahara
- University of Southern California, Keck School of Medicine, Department of Medicine, Division of Gastrointestinal and Liver Diseases, Los Angeles, California, USA.,Research and Development Department, PhoenixBio, Co., Ltd, Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Yuji Ishida
- University of Southern California, Keck School of Medicine, Department of Medicine, Division of Gastrointestinal and Liver Diseases, Los Angeles, California, USA.,Research and Development Department, PhoenixBio, Co., Ltd, Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan
| | - Jae Jin Lee
- University of Southern California, Keck School of Medicine, Department of Molecular Microbiology & Immunology, Los Angeles, California, USA
| | - Meng Li
- University of Southern California, Norris Medical Library, Bioinformatics Service Program, Los Angeles, California, USA
| | - Yasuhito Tanaka
- Department of Gastroenterology and Hepatology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan
| | - Hyungjin Eoh
- University of Southern California, Keck School of Medicine, Department of Molecular Microbiology & Immunology, Los Angeles, California, USA
| | - Yusuke Higuchi
- Department of Molecular Medicine, Beckman Research Institute of City of Hope, Duarte, California, USA
| | - Takeshi Saito
- University of Southern California, Keck School of Medicine, Department of Medicine, Division of Gastrointestinal and Liver Diseases, Los Angeles, California, USA.,USC Research Center for Liver Diseases, Los Angeles, California, USA.,Corresponding author: Takeshi Saito, M.D., Ph.D., Associate Professor of Medicine, Molecular Microbiology & Immunology, and Pathology, USC Research Center for Liver Diseases, Division of Gastrointestinal and Liver Diseases, Keck School of Medicine of USC, University of Southern California, 2011 Zonal Avenue, HMR 801A, Los Angeles, CA 90033-9141, Phone: +1-323-442-2260, Fax:+1-323-442-5425,
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3
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Hossain M, Huda N, Bhuyan AK. A surprisingly simple three-state generic process for reversible protein denaturation by trifluoroethanol. Biophys Chem 2022; 291:106895. [PMID: 36182744 DOI: 10.1016/j.bpc.2022.106895] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 12/30/2022]
Abstract
Despite the rich knowledge of the influence of 2,2,2-trifluoroethanol (TFE) on the structure and conformation of peptides and proteins, the mode(s) of TFE-protein interactions and the mechanism by which TFE reversibly denatures a globular protein remain elusive. This study systematically examines TFE-induced equilibrium transition curves for six paradigmatic globular proteins by using basic fluorescence and circular dichroism measurements under neutral pH conditions. The results are remarkably simple. Low TFE invariably unfolds the tertiary structure of all proteins to produce the obligate intermediate (I) which retains nearly all of native-state secondary structure, but enables the formation of extra α-helices as the level of TFE is raised higher. Inspection of the transitions at once reveals that the tertiary structure unfolding is always a distinct process, necessitating the inclusion of at least one obligate intermediate in the TFE-induced protein denaturation. It appears that the intermediate in the minimal unfolding mechanism N⇌I⇌D somehow acquires higher α-helical propensity to generate α-helices in excess of that in the native state to produce the denatured state (D), also called the TFE state. The low TFE-populated intermediate I may be called a universal intermediate by virtue of its α-helical propensity. Contrary to many earlier suggestions, this study dismisses molten globule (MG)-like attribute of I or D.
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Affiliation(s)
- Mujahid Hossain
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Noorul Huda
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Abani K Bhuyan
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India.
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4
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Hiromoto T, Ikura T, Honjo E, Blaber M, Kuroki R, Tamada T. Creation of Cross-Linked Crystals With Intermolecular Disulfide Bonds Connecting Symmetry-Related Molecules Allows Retention of Tertiary Structure in Different Solvent Conditions. Front Mol Biosci 2022; 9:908394. [PMID: 35755825 PMCID: PMC9213883 DOI: 10.3389/fmolb.2022.908394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/05/2022] [Indexed: 11/13/2022] Open
Abstract
Protein crystals are generally fragile and sensitive to subtle changes such as pH, ionic strength, and/or temperature in their crystallization mother liquor. Here, using T4 phage lysozyme as a model protein, the three-dimensional rigidification of protein crystals was conducted by introducing disulfide cross-links between neighboring molecules in the crystal. The effect of cross-linking on the stability of the crystals was evaluated by microscopic observation and X-ray diffraction. When soaking the obtained cross-linked crystals into a precipitant-free solution, the crystals held their shape without dissolution and diffracted to approximately 1.1 Å resolution, comparable to that of the non-cross-linked crystals. Such cross-linked crystals maintained their diffraction even when immersed in other solutions with pH values from 4 to 10, indicating that the disulfide cross-linking made the packing contacts enforced and resulted in some mechanical strength in response to changes in the preservation conditions. Furthermore, the cross-linked crystals gained stability to permit soaking into solutions containing high concentrations of organic solvents. The results suggest the possibility of obtaining protein crystals for effective drug screening by introducing appropriate cross-linked disulfide bonds.
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Affiliation(s)
- Takeshi Hiromoto
- Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Ibaraki, Japan
| | - Teikichi Ikura
- Institute for Human Life Science, Ochanomizu University, Tokyo, Japan
| | - Eijiro Honjo
- Research and Development Division, ADTEC Co., Ltd., Oita, Japan
| | - Michael Blaber
- College of Medicine, Florida State University, Tallahassee, FL, United states
| | - Ryota Kuroki
- Quantum Beam Science Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Taro Tamada
- Institute for Quantum Life Science, National Institutes for Quantum Science and Technology, Ibaraki, Japan
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5
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Szabó CL, Sebák F, Bodor A. Monitoring Protein Global and Local Parameters in Unfolding and Binding Studies: The Extended Applicability of the Diffusion Coefficient─Molecular Size Empirical Relations. Anal Chem 2022; 94:7885-7891. [PMID: 35617314 DOI: 10.1021/acs.analchem.2c00481] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Protein unfolding and denaturation are main issues in biochemical and pharmaceutical research. Using a global parameter, the translational diffusion coefficient D, folded, unfolded, and intrinsically disordered proteins of a given molar mass M can be distinguished based on their distinct hydrodynamic properties. For broader applications, we provide generalized, PFG-NMR-based empirical D-M relations validated at different temperatures and ready to use with the corresponding corrections in different media. We demonstrate that these relations enable a more accurate molecular mass determination and show fewer potential errors than those of the common methods based on small-molecular diffusion standards. We monitor unfolding of three model proteins using 8 M urea and dimethyl sulfoxide (DMSO)-water mixtures as denaturing agents, highlighting the effect of disulfide bonds. Denaturation in 8 M urea is pH-dependent; in addition, for proteins with highly stable disulfide bonds, a reducing agent (TCEP) is required to achieve complete unfolding. Regarding the effect of local parameters, we show that at low DMSO concentrations─common conditions in pharmaceutical binding studies─the PFG-NMR-derived global parameters are not significantly affected. Still, the atomic environments can change, and the bound solvent molecule can inhibit the binding of a partner molecule. Using proteins with natural isotopic abundance, this effect can be proven by fast 1H-15N 2D correlation spectra. Our results enable fast and easy estimation of protein molecular mass and the degree of folding in various media; moreover, the effect of the cosolvent on the atomic-level structure can be traced without the need of isotope labeling.
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Affiliation(s)
- Csenge Lilla Szabó
- Institute of Chemistry, Analytical and BioNMR Laboratory, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary.,Hevesy György PhD School of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
| | - Fanni Sebák
- Institute of Chemistry, Analytical and BioNMR Laboratory, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
| | - Andrea Bodor
- Institute of Chemistry, Analytical and BioNMR Laboratory, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
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6
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Tejaswi Naidu K, Prakash Prabhu N. An able-cryoprotectant and a moderate denaturant: distinctive character of ethylene glycol on protein stability. J Biomol Struct Dyn 2022; 40:820-832. [DOI: 10.1080/07391102.2020.1819422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- K. Tejaswi Naidu
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - N. Prakash Prabhu
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
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7
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Komorek P, Jachimska B, Brand I. Adsorption of lysozyme on gold surfaces in the presence of an external electric potential. Bioelectrochemistry 2021; 142:107946. [PMID: 34507162 DOI: 10.1016/j.bioelechem.2021.107946] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/30/2021] [Accepted: 08/29/2021] [Indexed: 10/20/2022]
Abstract
Adsorbed protein films consist of essential building blocks of many biotechnological and biomedical devices. The electrostatic potential may significantly modulate the protein behaviour on surfaces, affecting their structure and biological activity. In this study, lysozyme was used to investigate the effects of applied electric potentials on adsorption and the protein structure. The pH and the surface charge determine the amount and secondary structure of adsorbed lysozyme on a gold surface. In-situ measurements using polarization modulation infrared reflection absorption spectroscopy indicated that the concentration of both the adsorbed anions and the lysozyme led to conformational changes in the protein film, which was demonstrated by a greater amount of aggregated β-sheets in films fabricated at net positive charges of the Au electrode (Eads > Epzc). The changes in secondary structure involved two parallel processes. One comprised changes in the hydration/hydrogen-bond network at helices, leading to diverse helical structures: α-, 310- and/or π-helices. In the second process β-turns, β-sheets, and random coils displayed an ability to form aggregated β-sheet structures. The study illuminates the understanding of electrical potential-dependent changes involved in the protein misfolding process.
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Affiliation(s)
- Paulina Komorek
- Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland
| | - Barbara Jachimska
- Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland.
| | - Izabella Brand
- Department of Chemistry, University of Oldenburg, 26111 Oldenburg, Germany.
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8
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Katsura S, Furuishi T, Ueda H, Yonemochi E. Synthesis and Characterization of Cholesteryl Conjugated Lysozyme (CHLysozyme). Molecules 2020; 25:molecules25163704. [PMID: 32823837 PMCID: PMC7465789 DOI: 10.3390/molecules25163704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 12/19/2022] Open
Abstract
Hydrophobic interaction is important for protein conformation. Conjugation of a hydrophobic group can introduce intermolecular hydrophobic contacts that can be contained within the molecule. It is possible that a strongly folded state can be formed in solution compared with the native state. In this study, we synthesized cholesteryl conjugated lysozyme (CHLysozyme) using lysozyme and cholesterol as the model protein and hydrophobic group, respectively. Cholesteryl conjugation to lysozyme was confirmed by nuclear-magnetic resonance. Differential-scanning calorimetry suggested that CHLysozyme was folded in solution. CHLysozyme secondary structure was similar to lysozyme, although circular dichroism spectra indicated differences to the tertiary structure. Fluorescence measurements revealed a significant increase in the hydrophobic surface of CHLysozyme compared with that of lysozyme; CHLysozyme self-associated by hydrophobic interaction of the conjugated cholesterol but the hydrophobic surface of CHLysozyme decreased with time. The results suggested that hydrophobic interaction changed from intramolecular interaction to an intermolecular interaction. Furthermore, the relative activity of CHLysozyme to lysozyme increased with time. Therefore, CHLysozyme likely forms a folded state with an extended durability of activity. Moreover, lysozyme was denatured in 100% DMSO but the local environment of tryptophan in CHLysozyme was similar to that of a native lysozyme. Thus, this study suggests that protein solution stability and resistance to organic solvents may be improved by conjugation of a hydrophobic group.
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Affiliation(s)
- Shinji Katsura
- Department of Physical Chemistry, School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; (S.K.); (T.F.); (H.U.)
- Formulation research Lab., Taiho Pharmaceutical Co., Ltd., 224-2, Ebisuno, Hiraishi, Kawauchi-cho, Tokushima 771-0194, Japan
| | - Takayuki Furuishi
- Department of Physical Chemistry, School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; (S.K.); (T.F.); (H.U.)
| | - Haruhisa Ueda
- Department of Physical Chemistry, School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; (S.K.); (T.F.); (H.U.)
| | - Etsuo Yonemochi
- Department of Physical Chemistry, School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan; (S.K.); (T.F.); (H.U.)
- Correspondence: ; Tel.: +81-3-5498-5048
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9
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Hirano A, Nagatoishi S, Wada M, Tsumoto K, Maluf KN, Arakawa T. Technical Capabilities and Limitations of Optical Spectroscopy and Calorimetry Using Water-Miscible Solvents: The Case of Dimethyl Sulfoxide, Acetonitrile, and 1,4-Dioxane. J Pharm Sci 2019; 109:524-531. [PMID: 31682831 DOI: 10.1016/j.xphs.2019.10.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/22/2019] [Accepted: 10/29/2019] [Indexed: 01/09/2023]
Abstract
In drug development, water-miscible solvents are commonly used to dissolve drug substances. Typical routine procedures in drug development include dilution of the stock drug solution into an aqueous solution containing target macromolecules for drug binding assays. However, water-miscible solvents impose some technical limitations on the assays on account of their light absorption and heat capacity. Here, we examined the effects of the dilution of 3 water-miscible solvents, that is, dimethyl sulfoxide, acetonitrile, and 1,4-dioxane, on the baseline stability and signal/noise ratio in circular dichroism spectroscopy, isothermal titration calorimetry, and differential scanning calorimetry. Dimethyl sulfoxide and 1,4-dioxane affect the signal/noise ratio of circular dichroism spectra at typically used concentrations due to their light absorbance. The water-miscible solvents generate interfering signals in the isothermal titration calorimetry due to their mixing heat. They show negative or positive slope in the differential scanning calorimetry. Such interfering effects of the solvents are reduced by appropriate dilution according to the analytical techniques. Because the water-miscible solvents have solubilization capacity for alkyl chain moieties and aromatic moieties of chemicals, drug substances containing these moieties can be dissolved into the solvents and then subjected to the analyses to examine their interactions with target proteins after appropriate dilution of the drug solutions.
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Affiliation(s)
- Atsushi Hirano
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan.
| | - Satoru Nagatoishi
- The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Momoyo Wada
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
| | - Kouhei Tsumoto
- The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Karl N Maluf
- Alliance Protein Laboratories, Division of KBI Biopharma, San Diego, California 92121
| | - Tsutomu Arakawa
- Alliance Protein Laboratories, Division of KBI Biopharma, San Diego, California 92121
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10
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Sood D, Kumar N, Singh A, Tomar V, Dass SK, Chandra R. Deciphering the Binding Mechanism of Noscapine with Lysozyme: Biophysical and Chemoinformatic Approaches. ACS OMEGA 2019; 4:16233-16241. [PMID: 31592173 PMCID: PMC6777127 DOI: 10.1021/acsomega.9b02578] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 09/04/2019] [Indexed: 05/26/2023]
Abstract
Lysozyme is a well-characterized protein in terms of its structure, dynamics, and functions. It has thus emerged as a potential target to understand protein-drug interactions. The aim of our study is to gain a biophysical outlook on the interaction of lysozyme (Lyz), a well-known model protein, with Noscapine, a potent tubulin-binding anticancer drug. Noscapine (Nos) is effective against a wide range of cancer and shows low toxicity and few side effects. We report the underlying mechanism of complex formation between Nos and Lyz using spectroscopic and advanced computational avenues. The spectroscopic techniques, that is, absorption and steady-state and time-resolved fluorescence, proved that Lyz-Nos forms a complex, and the quenching mechanism was of the static type. The binding constant was in the order of 103 indicative of moderate binding, while the stoichiometry of the protein-drug complex was 1:1 at 298 K. The secondary structural analysis using CD and UV thermal denaturation further confirmed the conformational changes in the protein upon binding with Nos. Molecular dynamics simulation studies confirmed the stable binding with minimum deviations in RMSD. The above conclusions are significant to the development of the pharmacokinetics and pharmacodynamic properties of Nos, and its successful interaction with a versatile protein like Lyz will help in overcoming its previous limitations.
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Affiliation(s)
- Damini Sood
- Department of Chemistry, University of
Delhi, Delhi 110007, India
| | - Neeraj Kumar
- Department of Chemistry, University of
Delhi, Delhi 110007, India
| | - Anju Singh
- Department of Chemistry, University of
Delhi, Delhi 110007, India
| | - Vartika Tomar
- Department of Chemistry, University of
Delhi, Delhi 110007, India
| | - Sujata K. Dass
- BLK
Super Speciality Hospital, Pusa Road, New Delhi 110005, India
| | - Ramesh Chandra
- Department of Chemistry, University of
Delhi, Delhi 110007, India
- Dr
.B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110007, India
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11
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The Effect of Dimethyl Sulfoxide on the Lysozyme Unfolding Kinetics, Thermodynamics, and Mechanism. Biomolecules 2019; 9:biom9100547. [PMID: 31569484 PMCID: PMC6843525 DOI: 10.3390/biom9100547] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 02/07/2023] Open
Abstract
The thermal stability of proteins in the presence of organic solvents and the search for ways to increase this stability are important topics in industrial biocatalysis and protein engineering. The denaturation of hen egg-white lysozyme in mixtures of water with dimethyl sulfoxide (DMSO) with a broad range of compositions was studied using a combination of differential scanning calorimetry (DSC), circular dichroism (CD), and spectrofluorimetry techniques. In this study, for the first time, the kinetics of unfolding of lysozyme in DMSO–water mixtures was characterized. In the presence of DMSO, a sharp decrease in near-UV CD and an increase in the fluorescence signal were observed at lower temperatures than the DSC denaturation peak. It was found that differences in the temperatures of the CD and DSC signal changes increase as the content of DMSO increases. Changes in CD and fluorescence are triggered by a break of the tertiary contacts, leading to an intermediate state, while the DSC peak corresponds to a subsequent complete loss of the native structure. In this way, the commonly used two-state model was proven to be unsuitable to describe the unfolding of lysozyme in the presence of DMSO. In kinetic studies, it was found that even high concentrations of DMSO do not drastically change the activation energy of the initial stage of unfolding associated with a disruption of the tertiary structure, while the enthalpy of denaturation shows a significant dependence on DMSO content. This observation suggests that the structure of the transition state upon unfolding remains similar to the structure of the native state.
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12
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Yadav NS, Choudhury D. Conformational perturbation of peptides in presence of polar organic solvents. J Mol Graph Model 2019; 89:1-12. [PMID: 30831385 DOI: 10.1016/j.jmgm.2019.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 02/08/2019] [Accepted: 02/20/2019] [Indexed: 11/17/2022]
Abstract
The critical role played by solvent environment in maintaining the conformational integrity of peptides and proteins is accepted without question. Numerous experiments have suggested that perturbing the solvent environment of peptides and proteins by the addition of polar organic solvents have important consequences for the conformation of these molecules. However, experimental studies of such perturbations often report different kinds of effects depending on the solvent used and/or the sequence/structure of the molecule under study. In this work we report a simulation based comparative study on the effects of adding two common organic solvents viz. Dimethyl sulfoxide (DMSO) and Acetonitrile (MeCN) on the dynamical conformation of a test peptide Ace-Gly-X-Gly-Nme where X is any amino acid. Our studies identify important differences in peptide solvation by these two solvents, which we attempt to correlate with the kinetic stability of the conformation, as well as the identity of the central 'X' residue in the test peptide.
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Affiliation(s)
- Neetu Singh Yadav
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Devapriya Choudhury
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India.
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13
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Effects of allantoin and dimethyl sulfoxide on the thermal aggregation of lysozyme. Int J Biol Macromol 2018; 119:180-185. [PMID: 30009897 DOI: 10.1016/j.ijbiomac.2018.07.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/02/2018] [Accepted: 07/11/2018] [Indexed: 11/24/2022]
Abstract
Allantoin is used to suppress protein aggregation without decreasing the melting temperature. However, the solubility of allantoin in water or buffer solutions is too low (approximately 30 mM at ambient temperature) to be used as a protein aggregation suppressor in various situations. Here we show that a high-concentration solution of allantoin in neat dimethyl sulfoxide (DMSO) is useful as a stock solution for the additive that controls protein aggregation. The allantoin concentration from 10 to 100 mM in 10% (v/v) DMSO significantly suppressed the thermal aggregation of hen egg white lysozyme as a model protein, with increasing allantoin concentration. The residual activity of lysozyme in 10% DMSO and 100 mM allantoin after heating at 90 °C for 10 min was increased >3-fold compared to that without allantoin. Thus, it was concluded that allantoin in DMSO is an effective stock solution for practical application in enhancing the recovery of enzymatic activity and suppressing the formation of small aggregate of protein.
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14
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Daschakraborty S. How do glycerol and dimethyl sulphoxide affect local tetrahedral structure of water around a nonpolar solute at low temperature? Importance of preferential interaction. J Chem Phys 2018; 148:134501. [PMID: 29626866 DOI: 10.1063/1.5019239] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Glycerol and dimethyl sulphoxide (DMSO) have vital roles in cryoprotection of living cells, tissues, etc. The above action has been directly linked with disruption of hydrogen (H-) bond structure and dynamics of water by these cosolvents at bulk region and around various complex units, such as peptide, amino acid, protein, and lipid membrane. However, the disruption of the local structure of the water solvent around a purely hydrophobic solute is still not studied extensively. The latter is also important in the context of stabilization of protein from cold denaturation. Through all-atom molecular dynamics simulation, we have investigated the comparative effect of glycerol and DMSO on the orientational order of water around a nonpolar solute at -5 °C. A steady reduction of the tetrahedral order of water is observed at bulk (>10 Å distance from the solute) and solute interface (<5.5 Å distance from the solute) with increasing the cosolvent concentration. Contrasting roles of glycerol and DMSO have been evidenced. While DMSO affects the H-bond structure of the interfacial water more than that of the bulk water, glycerol affects the water structure almost uniformly at all regions around the solute. Furthermore, while glycerol helps to retain water molecules at the interface, DMSO significantly reduces the water content in that region. We have put forward a plausible mechanism for these contrasting roles of these cosolvents. The solute-cosolvent hydrophobic-interaction-induced orientational alignment of an interfacial cosolvent molecule determines whether the involvement of the cosolvent molecules in H-bonding with solvent water in the interface is akin to the bulk region or not.
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15
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Halder R, Jana B. Unravelling the Composition-Dependent Anomalies of Pair Hydrophobicity in Water–Ethanol Binary Mixtures. J Phys Chem B 2018; 122:6801-6809. [DOI: 10.1021/acs.jpcb.8b02528] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Ritaban Halder
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Biman Jana
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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16
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Nandi S, Parui S, Halder R, Jana B, Bhattacharyya K. Interaction of proteins with ionic liquid, alcohol and DMSO and in situ generation of gold nano-clusters in a cell. Biophys Rev 2018; 10:757-768. [PMID: 29147940 PMCID: PMC5988615 DOI: 10.1007/s12551-017-0331-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 10/23/2017] [Indexed: 12/27/2022] Open
Abstract
In this review, we give a brief overview on how the interaction of proteins with ionic liquids, alcohols and dimethyl sulfoxide (DMSO) influences the stability, conformational dynamics and function of proteins/enzymes. We present experimental results obtained from fluorescence correlation spectroscopy on the effect of ionic liquid or alcohol or DMSO on the size (more precisely, the diffusion constant) and conformational dynamics of lysozyme, cytochrome c and human serum albumin in aqueous solution. The interaction of ionic liquid with biomolecules (e.g. protein, DNA etc.) has emerged as a current frontier. We demonstrate that ionic liquids are excellent stabilizers of protein and DNA and, in some cases, cause refolding of a protein already denatured by chemical denaturing agents. We show that in ethanol-water binary mixture, proteins undergo non-monotonic changes in size and dynamics with increasing ethanol content. We also discuss the effect of water-DMSO mixture on the stability of proteins. We demonstrate how large-scale molecular dynamics simulations have revealed the molecular origin of this observed phenomenon and provide a microscopic picture of the immediate environment of the biomolecules. Finally, we describe how favorable interactions of ionic liquids may be utilized for in situ generation of fluorescent gold nano-clusters for imaging a live cell.
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Affiliation(s)
- Somen Nandi
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India
| | - Sridip Parui
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India
| | - Ritaban Halder
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India
| | - Biman Jana
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India.
| | - Kankan Bhattacharyya
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, 700 032, India.
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, 462 066, India.
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17
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Kabir MZ, Hamzah NAB, Ghani H, Mohamad SB, Alias Z, Tayyab S. Biophysical and computational characterization of vandetanib-lysozyme interaction. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 189:485-494. [PMID: 28843881 DOI: 10.1016/j.saa.2017.08.051] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/14/2017] [Accepted: 08/17/2017] [Indexed: 06/07/2023]
Abstract
Interaction of an anticancer drug, vandetanib (VDB) with a ligand transporter, lysozyme (LYZ) was explored using multispectroscopic techniques, such as fluorescence, absorption and circular dichroism along with computational analysis. Fluorescence data and absorption results confirmed VDB-LYZ complexation. VDB-induced quenching was characterized as static quenching based on inverse correlation of KSV with temperature as well as kq values. The complex was characterized by the weak binding constant (Ka=4.96-3.14×103M-1). Thermodynamic data (ΔS=+12.82Jmol-1K-1; ΔH=-16.73kJmol-1) of VDB-LYZ interaction revealed participation of hydrophobic and van der Waals forces along with hydrogen bonds in VDB-LYZ complexation. Microenvironmental perturbations around tryptophan and tyrosine residues as well as secondary and tertiary structural alterations in LYZ upon addition of VDB were evident from the 3-D fluorescence, far- and near-UV CD spectral analyses, respectively. Interestingly, addition of VDB to LYZ significantly increased protein's thermostability. Molecular docking results suggested the location of VDB binding site near the LYZ active site while molecular dynamics simulation results suggested stability of VDB-LYZ complex. Presence of Mg2+, Ba2+ and Zn2+ was found to interfere with VDB-LYZ interaction.
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Affiliation(s)
- Md Zahirul Kabir
- Biomolecular Research Group, Biochemistry Programme, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Nur Aziean Binti Hamzah
- Biomolecular Research Group, Biochemistry Programme, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Hamidah Ghani
- Bioinformatics Programme, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Saharuddin B Mohamad
- Bioinformatics Programme, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia; Centre of Research for Computational Sciences and Informatics for Biology, Bioindustry, Environment, Agriculture and Healthcare, University of Malaya, Kuala Lumpur, Malaysia
| | - Zazali Alias
- Biomolecular Research Group, Biochemistry Programme, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Saad Tayyab
- Biomolecular Research Group, Biochemistry Programme, Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia; Centre of Research for Computational Sciences and Informatics for Biology, Bioindustry, Environment, Agriculture and Healthcare, University of Malaya, Kuala Lumpur, Malaysia.
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18
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Zhang Y, Zhang X, Tang J, Snow CD, Sun G, Kowalski AE, Hartje LF, Zhao N, Wang Y, Belfiore LA. Synthesis of luminescent lanthanide complexes within crosslinked protein crystal matrices. CrystEngComm 2018. [DOI: 10.1039/c8ce00318a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Eu(TTA)3phen was synthesized inside of crosslinked protein crystals. And we characterized the volumetric changes quantitatively induced by DMSO.
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19
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Amin MA, Halder R, Ghosh C, Jana B, Bhattacharyya K. Effect of alcohol on the structure of cytochrome C: FCS and molecular dynamics simulations. J Chem Phys 2017; 145:235102. [PMID: 28010091 DOI: 10.1063/1.4972065] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Effect of ethanol on the size and structure of a protein cytochrome C (Cyt C) is investigated using fluorescence correlation spectroscopy (FCS) and molecular dynamics (MD) simulations. For FCS studies, Cyt C is covalently labeled with a fluorescent probe, alexa 488. FCS studies indicate that on addition of ethanol, the size of the protein varies non-monotonically. The size of Cyt C increases (i.e., the protein unfolds) on addition of alcohol (ethanol) up to a mole fraction of 0.2 (44.75% v/v) and decreases at higher alcohol concentration. In order to provide a molecular origin of this structural transition, we explore the conformational free energy landscape of Cyt C as a function of radius of gyration (Rg) at different compositions of water-ethanol binary mixture using MD simulations. Cyt C exhibits a minimum at Rg ∼ 13 Å in bulk water (0% alcohol). Upon increasing ethanol concentration, a second minimum appears in the free energy surface with gradually larger Rg up to χEtOH ∼ 0.2 (44.75% v/v). This suggests gradual unfolding of the protein. At a higher concentration of alcohol (χEtOH > 0.2), the minimum at large Rg vanishes, indicating compaction. Analysis of the contact map and the solvent organization around protein indicates a preferential solvation of the hydrophobic residues by ethanol up to χEtOH = 0.2 (44.75% v/v) and this causes the gradual unfolding of the protein. At high concentration (χEtOH = 0.3 (58% v/v)), due to structural organization in bulk water-ethanol binary mixture, the extent of preferential solvation by ethanol decreases. This causes a structural transition of Cyt C towards a more compact state.
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Affiliation(s)
- Md Asif Amin
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Ritaban Halder
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Catherine Ghosh
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Biman Jana
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Kankan Bhattacharyya
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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20
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Sirotkin VA, Kuchierskaya AA. Lysozyme in water-acetonitrile mixtures: Preferential solvation at the inner edge of excess hydration. J Chem Phys 2017; 146:215101. [PMID: 28576085 DOI: 10.1063/1.4984116] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Preferential solvation/hydration is an effective way for regulating the mechanism of the protein destabilization/stabilization. Organic solvent/water sorption and residual enzyme activity measurements were performed to monitor the preferential solvation/hydration of hen egg-white lysozyme at high and low water content in acetonitrile at 25 °C. The obtained results show that the protein destabilization/stabilization depends essentially on the initial hydration level of lysozyme and the water content in acetonitrile. There are three composition regimes for the dried lysozyme. At high water content, the lysozyme has a higher affinity for water than for acetonitrile. The residual enzyme activity values are close to 100%. At the intermediate water content, the dehydrated lysozyme has a higher affinity for acetonitrile than for water. A minimum on the residual enzyme activity curve was observed in this concentration range. At the lowest water content, the organic solvent molecules are preferentially excluded from the dried lysozyme, resulting in the preferential hydration. The residual catalytic activity is ∼80%, compared with that observed after incubation in pure water. Two distinct schemes are operative for the hydrated lysozyme. At high and intermediate water content, lysozyme is preferentially hydrated. However, in contrast to the dried protein, at the intermediate water content, the initially hydrated lysozyme has the increased preferential hydration parameters. At low water content, the preferential binding of the acetonitrile molecules to the initially hydrated lysozyme was detected. No residual enzyme activity was observed in the water-poor acetonitrile. Our data clearly show that the initial hydration level of the protein macromolecules is one of the key factors that govern the stability of the protein-water-organic solvent systems.
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Affiliation(s)
- Vladimir A Sirotkin
- A.M. Butlerov Institute of Chemistry, Kazan Federal University, Kremlevskaya Str., 18, Kazan 420008, Russia
| | - Alexandra A Kuchierskaya
- A.M. Butlerov Institute of Chemistry, Kazan Federal University, Kremlevskaya Str., 18, Kazan 420008, Russia
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21
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Maiangwa J, Mohamad Ali MS, Salleh AB, Rahman RNZRA, Normi YM, Mohd Shariff F, Leow TC. Lid opening and conformational stability of T1 Lipase is mediated by increasing chain length polar solvents. PeerJ 2017; 5:e3341. [PMID: 28533982 PMCID: PMC5438581 DOI: 10.7717/peerj.3341] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 04/21/2017] [Indexed: 11/20/2022] Open
Abstract
The dynamics and conformational landscape of proteins in organic solvents are events of potential interest in nonaqueous process catalysis. Conformational changes, folding transitions, and stability often correspond to structural rearrangements that alter contacts between solvent molecules and amino acid residues. However, in nonaqueous enzymology, organic solvents limit stability and further application of proteins. In the present study, molecular dynamics (MD) of a thermostable Geobacillus zalihae T1 lipase was performed in different chain length polar organic solvents (methanol, ethanol, propanol, butanol, and pentanol) and water mixture systems to a concentration of 50%. On the basis of the MD results, the structural deviations of the backbone atoms elucidated the dynamic effects of water/organic solvent mixtures on the equilibrium state of the protein simulations in decreasing solvent polarity. The results show that the solvent mixture gives rise to deviations in enzyme structure from the native one simulated in water. The drop in the flexibility in H2O, MtOH, EtOH and PrOH simulation mixtures shows that greater motions of residues were influenced in BtOH and PtOH simulation mixtures. Comparing the root mean square fluctuations value with the accessible solvent area (SASA) for every residue showed an almost correspondingly high SASA value of residues to high flexibility and low SASA value to low flexibility. The study further revealed that the organic solvents influenced the formation of more hydrogen bonds in MtOH, EtOH and PrOH and thus, it is assumed that increased intraprotein hydrogen bonding is ultimately correlated to the stability of the protein. However, the solvent accessibility analysis showed that in all solvent systems, hydrophobic residues were exposed and polar residues tended to be buried away from the solvent. Distance variation of the tetrahedral intermediate packing of the active pocket was not conserved in organic solvent systems, which could lead to weaknesses in the catalytic H-bond network and most likely a drop in catalytic activity. The conformational variation of the lid domain caused by the solvent molecules influenced its gradual opening. Formation of additional hydrogen bonds and hydrophobic interactions indicates that the contribution of the cooperative network of interactions could retain the stability of the protein in some solvent systems. Time-correlated atomic motions were used to characterize the correlations between the motions of the atoms from atomic coordinates. The resulting cross-correlation map revealed that the organic solvent mixtures performed functional, concerted, correlated motions in regions of residues of the lid domain to other residues. These observations suggest that varying lengths of polar organic solvents play a significant role in introducing dynamic conformational diversity in proteins in a decreasing order of polarity.
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Affiliation(s)
- Jonathan Maiangwa
- Department of Cell and Molecular Biology/Enzyme Microbial Technology Research center/Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Serlangor, Malaysia
| | - Mohd Shukuri Mohamad Ali
- Department of Biochemistry/Enzyme Microbial Technology Research center/Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Abu Bakar Salleh
- Department of Biochemistry/Enzyme Microbial Technology Research center/Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Raja Noor Zaliha Raja Abd Rahman
- Department of Microbiology/Enzyme Microbial Technology Research center/Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Yahaya M Normi
- Department of Cell and Molecular Biology/Enzyme Microbial Technology Research center/Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Serlangor, Malaysia
| | - Fairolniza Mohd Shariff
- Department of Microbiology/Enzyme Microbial Technology Research center/Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Thean Chor Leow
- Department of Cell and Molecular Biology/Enzyme and Microbial Technology Research center/Faculty of Biotechnology and Biomolecular Science/Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
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22
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Basu A, Suresh Kumar G. Interaction and inhibitory influence of the azo dye carmoisine on lysozyme amyloid fibrillogenesis. MOLECULAR BIOSYSTEMS 2017. [DOI: 10.1039/c7mb00207f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The azo dye carmoisine has a significant inhibitory effect on fibrillogenesis in lysozyme.
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Affiliation(s)
- Anirban Basu
- Biophysical Chemistry Laboratory
- Organic & Medicinal Chemistry Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata 700 032
- India
| | - Gopinatha Suresh Kumar
- Biophysical Chemistry Laboratory
- Organic & Medicinal Chemistry Division
- CSIR-Indian Institute of Chemical Biology
- Kolkata 700 032
- India
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23
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Srivastava KR, Goyal B, Kumar A, Durani S. Scrutiny of electrostatic-driven conformational ordering of polypeptide chains in DMSO: a study with a model oligopeptide. RSC Adv 2017. [DOI: 10.1039/c7ra02137b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The molecular mechanism of DMSO-induced stabilisation of β-sheets is attributed to the combination of polar electrostatic interactions among side chains, and backbone desolvation through bulky side chains which promotes backbone hydrogen bonding.
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Affiliation(s)
| | - Bhupesh Goyal
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076
- India
| | - Anil Kumar
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076
- India
| | - Susheel Durani
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076
- India
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24
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Preferential solvation of lysozyme in dimethyl sulfoxide/water binary mixture probed by terahertz spectroscopy. Biophys Chem 2016; 216:31-36. [DOI: 10.1016/j.bpc.2016.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 06/14/2016] [Accepted: 06/14/2016] [Indexed: 11/21/2022]
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25
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Ghosh R, Samajdar RN, Bhattacharyya AJ, Bagchi B. Composition dependent multiple structural transformations of myoglobin in aqueous ethanol solution: a combined experimental and theoretical study. J Chem Phys 2015; 143:015103. [PMID: 26156494 DOI: 10.1063/1.4923003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Experimental studies (circular dichroism and ultra-violet (UV) absorption spectra) and large scale atomistic molecular dynamics simulations (accompanied by order parameter analyses) are combined to establish a number of remarkable (and unforeseen) structural transformations of protein myoglobin in aqueous ethanol mixture at various ethanol concentrations. The following results are particularly striking. (1) Two well-defined structural regimes, one at xEtOH ∼ 0.05 and the other at xEtOH ∼ 0.25, characterized by formation of distinct partially folded conformations and separated by a unique partially unfolded intermediate state at xEtOH ∼ 0.15, are identified. (2) Existence of non-monotonic composition dependence of (i) radius of gyration, (ii) long range contact order, (iii) residue specific solvent accessible surface area of tryptophan, and (iv) circular dichroism spectra and UV-absorption peaks are observed. Interestingly at xEtOH ∼ 0.15, time averaged value of the contact order parameter of the protein reaches a minimum, implying that this conformational state can be identified as a molten globule state. Multiple structural transformations well known in water-ethanol binary mixture appear to have considerably stronger effects on conformation and dynamics of the protein. We compare the present results with studies in water-dimethyl sulfoxide mixture where also distinct structural transformations are observed along with variation of co-solvent composition.
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Affiliation(s)
- R Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - R N Samajdar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | | | - B Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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26
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Physicochemical study of the interaction of lysozyme with surface active ionic liquid 1-butyl-3-methylimidazolium octylsulfate [BMIM] [OS] in aqueous and buffer media. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.07.052] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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27
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McGovern RE, Snarr BD, Lyons JA, McFarlane J, Whiting AL, Paci I, Hof F, Crowley PB. Structural study of a small molecule receptor bound to dimethyllysine in lysozyme. Chem Sci 2015; 6:442-449. [PMID: 25530835 PMCID: PMC4266562 DOI: 10.1039/c4sc02383h] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Lysine is a ubiquitous residue on protein surfaces. Post translational modifications of lysine, including methylation to the mono-, di- or trimethylated amine result in chemical and structural alterations that have major consequences for protein interactions and signalling pathways. Small molecules that bind to methylated lysines are potential tools to modify such pathways. To make progress in this direction, detailed structural data of ligands in complex with methylated lysine is required. Here, we report a crystal structure of p-sulfonatocalix[4]arene (sclx4) bound to methylated lysozyme in which the lysine residues were chemically modified from Lys-NH3+ to Lys-NH(Me2)+. Of the six possible dimethyllysine sites, sclx4 selected Lys116-Me2 and the dimethylamino substituent was deeply buried in the calixarene cavity. This complex confirms the tendency for Lys-Me2 residues to form cation-π interactions, which have been shown to be important in protein recognition of histone tails bearing methylated lysines. Supporting data from NMR spectroscopy and MD simulations confirm the selectivity for Lys116-Me2 in solution. The structure presented here may serve as a stepping stone to the development of new biochemical reagents that target methylated lysines.
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Affiliation(s)
- Róise E McGovern
- School of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland
| | - Brendan D Snarr
- Department of Chemistry, University of Victoria, British Columbia, V8W 3V6, Canada
| | - Joseph A Lyons
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin, Ireland
| | - James McFarlane
- Department of Chemistry, University of Victoria, British Columbia, V8W 3V6, Canada
| | - Amanda L Whiting
- Department of Chemistry, University of Victoria, British Columbia, V8W 3V6, Canada
| | - Irina Paci
- Department of Chemistry, University of Victoria, British Columbia, V8W 3V6, Canada
| | - Fraser Hof
- Department of Chemistry, University of Victoria, British Columbia, V8W 3V6, Canada
| | - Peter B Crowley
- School of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland
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28
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Ghosh R, Roy S, Bagchi B. Multidimensional free energy surface of unfolding of HP-36: Microscopic origin of ruggedness. J Chem Phys 2014; 141:135101. [DOI: 10.1063/1.4896762] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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29
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Koley S, Kaur H, Ghosh S. Probe dependent anomalies in the solvation dynamics of coumarin dyes in dimethyl sulfoxide–glycerol binary solvent: confirming the local environments are different for coumarin dyes. Phys Chem Chem Phys 2014; 16:22352-63. [DOI: 10.1039/c4cp03525a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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30
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Chattoraj S, Mandal AK, Bhattacharyya K. Effect of ethanol-water mixture on the structure and dynamics of lysozyme: A fluorescence correlation spectroscopy study. J Chem Phys 2014; 140:115105. [DOI: 10.1063/1.4868642] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Jash C, Kumar GS. Binding of alkaloids berberine, palmatine and coralyne to lysozyme: a combined structural and thermodynamic study. RSC Adv 2014. [DOI: 10.1039/c3ra46053c] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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32
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Peng F, Liu Y, Li X, Sun L, Zhao D, Wang Q, Ma G, Su Z. PEGylation of G-CSF in organic solvent markedly increase the efficacy and reactivity through protein unfolding, hydrolysis inhibition and solvent effect. J Biotechnol 2014; 170:42-9. [DOI: 10.1016/j.jbiotec.2013.10.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/16/2013] [Accepted: 10/31/2013] [Indexed: 01/08/2023]
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33
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Ghosh S, Chattoraj S, Chowdhury R, Bhattacharyya K. Structure and dynamics of lysozyme in DMSO–water binary mixture: fluorescence correlation spectroscopy. RSC Adv 2014. [DOI: 10.1039/c4ra00719k] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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34
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Roy S, Bagchi B. Solvation dynamics of tryptophan in water-dimethyl sulfoxide binary mixture: In search of molecular origin of composition dependent multiple anomalies. J Chem Phys 2013; 139:034308. [DOI: 10.1063/1.4813417] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Pabbathi A, Patra S, Samanta A. Structural transformation of bovine serum albumin induced by dimethyl sulfoxide and probed by fluorescence correlation spectroscopy and additional methods. Chemphyschem 2013; 14:2441-9. [PMID: 23780704 DOI: 10.1002/cphc.201300313] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/01/2013] [Indexed: 11/10/2022]
Abstract
Determining the structure of a protein and its transformation under different conditions is key to understanding its activity. The structural stability and activity of proteins in aqueous-organic solvent mixtures, which is an intriguing topic of research in biochemistry, is dependent on the nature of the protein and the properties of the medium. Herein, the effect of a commonly used cosolvent, dimethyl sulfoxide (DMSO), on the structure and conformational dynamics of bovine serum albumin (BSA) protein is studied by fluorescence correlation spectroscopy (FCS) measurements on fluorescein isothiocyanate (FITC)-labeled BSA. The FCS study reveals a change of the hydrodynamic radius of BSA from 3.7 nm in the native state to 7.0 nm in the presence of 40% DMSO, which suggests complete unfolding of the protein under these conditions. Fluorescence self-quenching of FITC has been exploited to understand the conformational dynamics of BSA. The time constant of the conformational dynamics of BSA is found to change from 35 μs in its native state to 50 μs as the protein unfolds with increasing DMSO concentration. The FCS results are corroborated by the near-UV circular dichroism spectra of the protein, which suggest a loss of its tertiary structure with increasing concentration of DMSO. The intrinsic fluorescence of BSA and the fluorescence response of 1-anilinonaphthalene-8-sulfonic acid, used as a probe molecule, provide information that is consistent with the FCS measurements, except that aggregation of BSA is observed in the presence of 40% DMSO in the ensemble measurements.
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Affiliation(s)
- Ashok Pabbathi
- School of Chemistry, University of Hyderabad, Gachi Bowli, Hyderabad, India
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Stepankova V, Damborsky J, Chaloupkova R. Organic co-solvents affect activity, stability and enantioselectivity of haloalkane dehalogenases. Biotechnol J 2013; 8:719-29. [PMID: 23420811 DOI: 10.1002/biot.201200378] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/21/2013] [Accepted: 02/12/2013] [Indexed: 01/12/2023]
Abstract
Haloalkane dehalogenases are microbial enzymes with a wide range of biotechnological applications, including biocatalysis. The use of organic co-solvents to solubilize their hydrophobic substrates is often necessary. In order to choose the most compatible co-solvent, the effects of 14 co-solvents on activity, stability and enantioselectivity of three model enzymes, DbjA, DhaA, and LinB, were evaluated. All co-solvents caused at high concentration loss of activity and conformational changes. The highest inactivation was induced by tetrahydrofuran, while more hydrophilic co-solvents, such as ethylene glycol and dimethyl sulfoxide, were better tolerated. The effects of co-solvents at low concentration were different for each enzyme-solvent pair. An increase in DbjA activity was induced by the majority of organic co-solvents tested, while activities of DhaA and LinB decreased at comparable concentrations of the same co-solvent. Moreover, a high increase of DbjA enantioselectivity was observed. Ethylene glycol and 1,4-dioxane were shown to have the most positive impact on the enantioselectivity. The favorable influence of these co-solvents on both activity and enantioselectivity makes DbjA suitable for biocatalytic applications. This study represents the first investigation of the effects of organic co-solvents on the biocatalytic performance of haloalkane dehalogenases and will pave the way for their broader use in industrial processes.
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Affiliation(s)
- Veronika Stepankova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, Masaryk University, Brno, Czech Republic
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Tretyakova T, Shushanyan M, Partskhaladze T, Makharadze M, van Eldik R, Khoshtariya DE. Simplicity within the complexity: bilateral impact of DMSO on the functional and unfolding patterns of α-chymotrypsin. Biophys Chem 2013; 175-176:17-27. [PMID: 23524288 DOI: 10.1016/j.bpc.2013.02.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Revised: 02/05/2013] [Accepted: 02/09/2013] [Indexed: 10/27/2022]
Abstract
New understanding of the fundamental links between protein stability, conformational flexibility and function, can be gained through synergic studies on their catalytic and folding/unfolding properties under the influence of stabilizing/destabilizing additives. We explored an impact of dimethyl sulfoxide (DMSO), the moderate effector of multilateral action, on the kinetic (functional) and thermodynamic (thermal unfolding) patterns of a hydrolytic enzyme, α-chymotrypsin (α-CT), over a wide range of additive concentrations, 0-70% (v/v). Both the calorimetric and kinetic data exhibited rich behavior pointing to the complex interplay of global/local stability (and flexibility) patterns. The complex action of DMSO is explained through the negative and positive preferential solvation motifs that prevail for the extreme opposite, native-like and unfolded states, respectively, implying essential stabilization of compact domains by enhancement of interfacial water networks and destabilization of a flexible active site by direct binding of DMSO to the unoccupied specific positions intended for elongated polypeptide substrates.
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Affiliation(s)
- Tatyana Tretyakova
- Institute for Biophysics and Bionanosciences at the Department of Physics, I. Javakhishvili Tbilisi State University, I. Chavchavadze Ave. 3, 0128 Tbilisi, Georgia
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Cubrilovic D, Zenobi R. Influence of dimehylsulfoxide on protein-ligand binding affinities. Anal Chem 2013; 85:2724-30. [PMID: 23347283 DOI: 10.1021/ac303197p] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Because of its favorable physicochemical properties, DMSO is the standard solvent for sample storage and handling of compounds in drug discovery. To date, little attention was given to how DMSO influences protein-ligand binding strengths. In this study we investigated the effects of DMSO on different noncovalent protein-ligand complexes, in particular in terms of the binding affinities, which we determined using nanoESI-MS. For the investigation, three different protein-ligand complexes were chosen: trypsin-Pefabloc, lysozyme-tri-N-acetylchitotriose (NAG3), and carbonic anhydrase-chlorothiazide. The DMSO content in the nanoESI buffer was increased systematically from 0.5 to 8%. For all three model systems, it was shown that the binding affinity decreases upon addition of DMSO. Even 0.5-1% DMSO alters the KD values, in particular for the tight binding system carbonic anhydrase-chlorothiazide. The determined dissociation constant (KD) is up to 10 times higher than for a DMSO-free sample in the case of carbonic anhydrase-chlorothiazide binding. For the trypsin-Pefabloc and lysozyme-NAG3 complexes, the dissociation constants are 7 and 3 times larger, respectively, in the presence of DMSO. This work emphasizes the importance of effects of DMSO as a co-solvent for quantification of protein-ligand binding strengths in the early stages of drug discovery.
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Affiliation(s)
- Dragana Cubrilovic
- Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
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Batista ANL, Batista Jr JM, Bolzani VS, Furlan M, Blanch EW. Selective DMSO-induced conformational changes in proteins from Raman optical activity. Phys Chem Chem Phys 2013; 15:20147-52. [DOI: 10.1039/c3cp53525h] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Roy S, Bagchi B. Chemical Unfolding of Chicken Villin Headpiece in Aqueous Dimethyl Sulfoxide Solution: Cosolvent Concentration Dependence, Pathway, and Microscopic Mechanism. J Phys Chem B 2012; 117:4488-502. [DOI: 10.1021/jp308589b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Susmita Roy
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore
560012, India
| | - Biman Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore
560012, India
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Roy S, Jana B, Bagchi B. Dimethyl sulfoxide induced structural transformations and non-monotonic concentration dependence of conformational fluctuation around active site of lysozyme. J Chem Phys 2012; 136:115103. [PMID: 22443797 DOI: 10.1063/1.3694268] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Experimental studies have observed significant changes in both structure and function of lysozyme (and other proteins) on addition of a small amount of dimethyl sulfoxide (DMSO) in aqueous solution. Our atomistic molecular dynamic simulations of lysozyme in water-DMSO reveal the following sequence of changes on increasing DMSO concentration. (i) At the initial stage (around 5% DMSO concentration) protein's conformational flexibility gets markedly suppressed. From study of radial distribution functions, we attribute this to the preferential solvation of exposed protein hydrophobic residues by the methyl groups of DMSO. (ii) In the next stage (10-15% DMSO concentration range), lysozome partially unfolds accompanied by an increase both in fluctuation and in exposed protein surface area. (iii) Between 15-20% concentration ranges, both conformational fluctuation and solvent accessible protein surface area suddenly decrease again indicating the formation of an intermediate collapse state. These results are in good agreement with near-UV circular dichroism (CD) and fluorescence studies. We explain this apparently surprising behavior in terms of a structural transformation which involves clustering among the methyl groups of DMSO. (iv) Beyond 20% concentration of DMSO, the protein starts its final sojourn towards the unfolding state with further increase in conformational fluctuation and loss in native contacts. Most importantly, analysis of contact map and fluctuation near the active site reveal that both partial unfolding and conformational fluctuations are centered mostly on the hydrophobic core of active site of lysozyme. Our results could offer a general explanation and universal picture of the anomalous behavior of protein structure-function observed in the presence of cosolvents (DMSO, ethanol, tertiary butyl alcohol, dioxane) at their low concentrations.
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Affiliation(s)
- Susmita Roy
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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Srokowski EM, Woodhouse KA. Development and characterisation of novel cross-linked bio-elastomeric materials. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 19:785-99. [DOI: 10.1163/156856208784522038] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Elizabeth M. Srokowski
- a Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, RM 363, Toronto, ON, Canada M5S 3E5
| | - Kimberly A. Woodhouse
- b Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, RM 363, Toronto, ON, Canada M5S 3E5; Advanced Regenerative Tissue Engineering Centre, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, Canada M4N 3M5
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Ni XJ, Delelis O, Charpentier C, Storto A, Collin G, Damond F, Descamps D, Mouscadet JF. G140S/Q148R and N155H mutations render HIV-2 Integrase resistant to raltegravir whereas Y143C does not. Retrovirology 2011; 8:68. [PMID: 21854605 PMCID: PMC3170264 DOI: 10.1186/1742-4690-8-68] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 08/19/2011] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND HIV-2 is endemic in West Africa and has spread throughout Europe. However, the alternatives for HIV-2-infected patients are more limited than for HIV-1. Raltegravir, an integrase inhibitor, is active against wild-type HIV-2, with a susceptibility to this drug similar to that of HIV-1, and is therefore a promising option for use in the treatment of HIV-2-infected patients. Recent studies have shown that HIV-2 resistance to raltegravir involves one of three resistance mutations, N155H, Q148R/H and Y143C, previously identified as resistance determinants in the HIV-1 integrase coding sequence. The resistance of HIV-1 IN has been confirmed in vitro for mutated enzymes harboring these mutations, but no such confirmation has yet been obtained for HIV-2. RESULTS The integrase coding sequence was amplified from plasma samples collected from ten patients infected with HIV-2 viruses, of whom three RAL-naïve and seven on RAL-based treatment at the time of virological failure. The genomes of the resistant strains were cloned and three patterns involving N155H, G140S/Q148R or Y143C mutations were identified. Study of the susceptibility of integrases, either amplified from clinical isolates or obtained by mutagenesis demonstrated that mutations at positions 155 and 148 render the integrase resistant to RAL. The G140S mutation conferred little resistance, but compensated for the catalytic defect due to the Q148R mutation. Conversely, Y143C alone did not confer resistance to RAL unless E92Q is also present. Furthermore, the introduction of the Y143C mutation into the N155H resistant background decreased the resistance level of enzymes containing the N155H mutation. CONCLUSION This study confirms that HIV-2 resistance to RAL is due to the N155H, G140S/Q148R or E92Q/Y143C mutations. The N155H and G140S/Q148R mutations make similar contributions to resistance in both HIV-1 and HIV-2, but Y143C is not sufficient to account for the resistance of HIV-2 genomes harboring this mutation. For Y143C to confer resistance in vitro, it must be accompanied by E92Q, which therefore plays a more important role in the HIV-2 context than in the HIV-1 context. Finally, the Y143C mutation counteracts the resistance conferred by the N155H mutation, probably accounting for the lack of detection of these mutations together in a single genome.
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Affiliation(s)
- Xiao-Ju Ni
- LBPA, CNRS, Ecole Normale Supérieure de Cachan, Cachan, France
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Mangani S, Cancian L, Leone R, Pozzi C, Lazzari S, Luciani R, Ferrari S, Costi MP. Identification of the binding modes of N-phenylphthalimides inhibiting bacterial thymidylate synthase through X-ray crystallography screening. J Med Chem 2011; 54:5454-67. [PMID: 21696158 DOI: 10.1021/jm2005018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To identify specific bacterial thymidylate synthase (TS) inhibitors, we exploited phenolphthalein (PTH), which inhibits both bacterial and human enzymes. The X-ray crystal structure of Lactobacillus casei TS (LcTS) that binds PTH showed multiple binding modes of the inhibitor, which prevented a classical structure-based drug design approach. To overcome this issue, we synthesized two phthalimidic libraries that were tested against TS enzymes and then we performed X-ray crystallographic screening of the active compounds. Compounds 6A, 8A, and 12A showed 40-fold higher affinity for bacterial TS than human TS. The X-ray crystallographic screening characterized the binding mode of six inhibitors in complexes with LcTS. Of these, 20A, 23A, and 24A showed a common unique binding mode, whereas 8A showed a different, unique binding mode. A comparative analysis of the LcTS X-ray complexes that were obtained with the pathogenic TS enabled the selection of compounds 8A and 23A as specific compounds and starting points to be exploited for the specific inhibition of pathogen enzymes.
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Affiliation(s)
- Stefano Mangani
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Modena e Reggio Emilia, Modena, Italy.
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Fang R, Jing H, Chai Z, Zhao G, Stoll S, Ren F, Liu F, Leng X. Study of the physicochemical properties of the BSA: flavonoid nanoparticle. Eur Food Res Technol 2011. [DOI: 10.1007/s00217-011-1522-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Design and characterization of protein-quercetin bioactive nanoparticles. J Nanobiotechnology 2011; 9:19. [PMID: 21586116 PMCID: PMC3116464 DOI: 10.1186/1477-3155-9-19] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/17/2011] [Indexed: 11/10/2022] Open
Abstract
Background The synthesis of bioactive nanoparticles with precise molecular level control is a major challenge in bionanotechnology. Understanding the nature of the interactions between the active components and transport biomaterials is thus essential for the rational formulation of bio-nanocarriers. The current study presents a single molecule of bovine serum albumin (BSA), lysozyme (Lys), or myoglobin (Mb) used to load hydrophobic drugs such as quercetin (Q) and other flavonoids. Results Induced by dimethyl sulfoxide (DMSO), BSA, Lys, and Mb formed spherical nanocarriers with sizes less than 70 nm. After loading Q, the size was further reduced by 30%. The adsorption of Q on protein is mainly hydrophobic, and is related to the synergy of Trp residues with the molecular environment of the proteins. Seven Q molecules could be entrapped by one Lys molecule, 9 by one Mb, and 11 by one BSA. The controlled releasing measurements indicate that these bioactive nanoparticles have long-term antioxidant protection effects on the activity of Q in both acidic and neutral conditions. The antioxidant activity evaluation indicates that the activity of Q is not hindered by the formation of protein nanoparticles. Other flavonoids, such as kaempferol and rutin, were also investigated. Conclusions BSA exhibits the most remarkable abilities of loading, controlled release, and antioxidant protection of active drugs, indicating that such type of bionanoparticles is very promising in the field of bionanotechnology.
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Voets IK, Cruz WA, Moitzi C, Lindner P, Arêas EPG, Schurtenberger P. DMSO-Induced Denaturation of Hen Egg White Lysozyme. J Phys Chem B 2010; 114:11875-83. [DOI: 10.1021/jp103515b] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ilja K. Voets
- Adolphe Merkle Institute, University of Fribourg, Route de l’Ancienne Papeterie, P.O. Box 209, CH-1723 Marly 1, Switzerland, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, CEP 05508-000 São Paulo, SP, Brazil, and Institut Max von Laue-Paul Langevin, F-38042 Grenoble Cedex 9, France
| | - Willemberg A. Cruz
- Adolphe Merkle Institute, University of Fribourg, Route de l’Ancienne Papeterie, P.O. Box 209, CH-1723 Marly 1, Switzerland, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, CEP 05508-000 São Paulo, SP, Brazil, and Institut Max von Laue-Paul Langevin, F-38042 Grenoble Cedex 9, France
| | - Christian Moitzi
- Adolphe Merkle Institute, University of Fribourg, Route de l’Ancienne Papeterie, P.O. Box 209, CH-1723 Marly 1, Switzerland, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, CEP 05508-000 São Paulo, SP, Brazil, and Institut Max von Laue-Paul Langevin, F-38042 Grenoble Cedex 9, France
| | - Peter Lindner
- Adolphe Merkle Institute, University of Fribourg, Route de l’Ancienne Papeterie, P.O. Box 209, CH-1723 Marly 1, Switzerland, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, CEP 05508-000 São Paulo, SP, Brazil, and Institut Max von Laue-Paul Langevin, F-38042 Grenoble Cedex 9, France
| | - Elizabeth P. G. Arêas
- Adolphe Merkle Institute, University of Fribourg, Route de l’Ancienne Papeterie, P.O. Box 209, CH-1723 Marly 1, Switzerland, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, CEP 05508-000 São Paulo, SP, Brazil, and Institut Max von Laue-Paul Langevin, F-38042 Grenoble Cedex 9, France
| | - Peter Schurtenberger
- Adolphe Merkle Institute, University of Fribourg, Route de l’Ancienne Papeterie, P.O. Box 209, CH-1723 Marly 1, Switzerland, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, CEP 05508-000 São Paulo, SP, Brazil, and Institut Max von Laue-Paul Langevin, F-38042 Grenoble Cedex 9, France
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Pal S, Chen Z, Xu X, Mikhailova M, Steffensen B. Co-purified gelatinases alter the stability and biological activities of human plasma fibronectin preparations. J Periodontal Res 2010; 45:292-5. [PMID: 19909400 PMCID: PMC2872045 DOI: 10.1111/j.1600-0765.2009.01241.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Fibronectin (FN) is an important cell adhesion molecule that is used widely to characterize cell behavior. Preparations of FN purified from human plasma by gelatin-Sepharose affinity chromatography typically also contain gelatin-binding gelatinases that may cleave FN, reduce its stability and alter its biological activities. Available methods for separating gelatinases from FN are resource demanding. Therefore, our objective was to devise a time- and cost-efficient protocol for purification of gelatinase-free FN. MATERIAL AND METHODS Experiments tested the elution profiles for FN and gelatinases from gelatin-Sepharose using a concentration range (1-7%) of dimethyl sulfoxide (DMSO) and 4 m urea as eluants. Subsequently, we explored the sequential application of those eluants for differential elution of gelatinases and FN using a single affinity column. Finally, experiments characterized the stability of purified FN with or without contaminating gelatinases, as well as the effects of FN degradation on cell attachment and migration. RESULTS Assay optimization demonstrated that pre-elution with 3% DMSO efficiently eliminated gelatinases but not FN from gelatin-Sepharose, whereas subsequent elution with 4 m urea released FN. Sequential elutions with DMSO and urea produced gelatinase-free FN, which was more stable than FN eluted by urea only. Fibronectin degradation did not affect human gingival fibroblast attachment, but increased cell migration significantly. CONCLUSION The present experiments devised a time- and cost-efficient protocol for eliminating gelatinases during purification of human plasma FN. Gelatinase-free FN preparations had greater stability, which may be essential for experiments because FN fragments have altered biological activities compared with intact FN.
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Affiliation(s)
- S Pal
- Department of Periodontics and Biochemistry, University of Texas Health Science Center at San Antonio, TX 78229-3900, USA
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Percy AJ, Schriemer DC. Rheostatic control of tryptic digestion in a microscale fluidic system. Anal Chim Acta 2010; 657:53-9. [DOI: 10.1016/j.aca.2009.10.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 09/17/2009] [Accepted: 10/09/2009] [Indexed: 11/25/2022]
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Guerrero-Mendiola C, Oria-Hernández J, Ramírez-Silva L. Kinetics of the thermal inactivation and aggregate formation of rabbit muscle pyruvate kinase in the presence of trehalose. Arch Biochem Biophys 2009; 490:129-36. [PMID: 19703407 DOI: 10.1016/j.abb.2009.08.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 08/19/2009] [Accepted: 08/19/2009] [Indexed: 11/29/2022]
Abstract
In a previous study we found that 30-40% dimethylsulfoxide induces the active conformation of rabbit muscle pyruvate kinase. Because dimethylsulfoxide is known to perturb structure and function of many proteins, we have explored the effect of trehalose on the kinetics of thermal inactivation and stability of pyruvate kinase; this is because trehalose, in contrast to dimethyl sulfoxide, is totally excluded from the hydration shell of proteins. The results show that 600 mM trehalose inhibits the activity of pyruvate kinase by about 20% at 25 degrees C, however, trehalose protects pyruvate kinase from thermal inactivation at 60 degrees C, increases the Tm(app) of unfolding by 7.2 degrees C, induces a more compact state, and stabilizes its tetrameric structure. The inactivation process is irreversible due to the formation of protein aggregates. Trehalose diminishes the rate of formation of intermediates with propensity to aggregate, but does not affect the extent of aggregation. Remarkably, trehalose affects the aggregation process by inducing aggregates with amyloid-like characteristics.
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Affiliation(s)
- Carlos Guerrero-Mendiola
- Departamento de Bioquímica, Facultad de Medicina, Apartado Postal 70-159, Universidad Nacional Autónoma de México, 04510 México, DF, Mexico
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