1
|
Khasawneh RR, Abu-El-Rub E. Comparing the effect of using 2-Mercaptoethanol in the cell culture medium of different cell passages of human mesenchymal stem cells. Cell Mol Biol (Noisy-le-grand) 2024; 70:35-39. [PMID: 38678630 DOI: 10.14715/cmb/2024.70.4.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Indexed: 05/01/2024]
Abstract
Preparing a suitable cell culture medium that supports the biological needs of the growing cells is crucial to enhancing the success rate of any in vitro and in vivo experiments and minimizing undesirable interferences. Mesenchymal stem cells ( MSCs) which are powerful regenerative stem cells require being grown in proper culture media to preserve their stemness and therapeutic properties. MSCs are usually grown in Dulbecco's Modified Eagle low glucose Medium (DMEM low glucose) which contains 5.6 mmol/L of glucose and is supplemented with Fetal Bovine Serum (FBS), antibiotics, and 2-Mercaptoethanol. The addition of 2-Mercaptoethanol to the cell culture medium was proposed long ago and has continued to be used until now. Despite the positive effects of adding 2-Mercaptoethanol in the cell culture medium, its use is still controversial and needs continuous updates to limit its interference with experimental treatments. Herein, we found that 2-Mercaptoethanol is beneficial to enhancing the proliferation and survival of MSCs at higher passage numbers while its effect is negligible for earlier passages. This concise study provides updates regarding the suitable time to add 2-Mercaptoethanol which can minimize its intermeddling with the experimental design and treatments.
Collapse
Affiliation(s)
- Ramada R Khasawneh
- Anatomy and Histology, Department of Basic Medical Sciences, Faculty of Medicine, Yarmouk University, Irbid, 21163, Jordan.
| | - Ejlal Abu-El-Rub
- Physiology and Pathophysiology, Department of Basic Medical Sciences, Faculty of Medicine, Yarmouk University, Irbid, 21163, Jordan.
| |
Collapse
|
2
|
Shaikhqasem A, Schmitt K, Valerius O, Ficner R. Crystal structure of human CRM1, covalently modified by 2-mercaptoethanol on Cys528, in complex with RanGTP. Acta Crystallogr F Struct Biol Commun 2021; 77:70-78. [PMID: 33682791 PMCID: PMC7938638 DOI: 10.1107/s2053230x2100203x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/21/2021] [Indexed: 11/23/2022] Open
Abstract
CRM1 is a nuclear export receptor that has been intensively targeted over the last decade for the development of antitumor and antiviral drugs. Structural analysis of several inhibitor compounds bound to CRM1 revealed that their mechanism of action relies on the covalent modification of a critical cysteine residue (Cys528 in the human receptor) located in the nuclear export signal-binding cleft. This study presents the crystal structure of human CRM1, covalently modified by 2-mercaptoethanol on Cys528, in complex with RanGTP at 2.58 Å resolution. The results demonstrate that buffer components can interfere with the characterization of cysteine-dependent inhibitor compounds.
Collapse
Affiliation(s)
- Alaa Shaikhqasem
- Department for Molecular Structural Biology, Georg-August-Universität Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Kerstin Schmitt
- Department of Molecular Microbiology and Genetics, Georg-August-Universität Göttingen, Grisebachstrasse 8, 37077 Göttingen, Germany
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics, Georg-August-Universität Göttingen, Grisebachstrasse 8, 37077 Göttingen, Germany
| | - Ralf Ficner
- Department for Molecular Structural Biology, Georg-August-Universität Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| |
Collapse
|
3
|
Cruz-Valencia R, Arvizu-Flores AA, Rosas-Rodríguez JA, Valenzuela-Soto EM. Effect of the drug cyclophosphamide on the activity of porcine kidney betaine aldehyde dehydrogenase. Mol Cell Biochem 2021; 476:1467-1475. [PMID: 33389495 DOI: 10.1007/s11010-020-04010-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/28/2020] [Indexed: 01/17/2023]
Abstract
The enzyme betaine aldehyde dehydrogenase (BADH EC 1.2.1.8) catalyzes the synthesis of glycine betaine (GB), an osmolyte and osmoprotectant. Also, it participates in several metabolic pathways in humans. All BADHs known have cysteine in the active site involved in the aldehyde binding, whereas the porcine kidney enzyme (pkBADH) also has a neighborhood cysteine, both sensitive to oxidation. The antineoplastic and immuno-suppressant pre-drug cyclophosphamide (CTX), and its bioactivation products, have two highly oxidating chlorine atoms. This work aimed to analyze the effect of CTX in the activity of porcine kidney betaine aldehyde dehydrogenase. PkBADH was incubated with varying CTX concentration (0 to 2.0 mM) at 25 °C and lost 50 % of its activity with 2.0 mM CTX. The presence of the coenzyme NAD+ (0.5 mM) decreased 95% the activity in 2.0 mM CTX. The substrate betaine aldehyde (0.05 and 0.4 mM, and the products NADH (0.1-0.5 mM) and GB (1 and 10 mM) did not have an effect on the enzyme inactivation by CTX. The reducing agents, dithiothreitol and β-mercaptoethanol, reverted the pkBADH inactivation, but reduced glutathione (GSH) was unable to restore the enzyme activity. Molecular docking showed that CTX could enter at the enzyme active site, where its chlorine atoms may interact with the catalytic and the neighboring cysteines. The results obtained show that CTX inactivates the pkBADH due to oxidation of the catalytic cysteine or because it oxidizes catalytic and neighborhood cysteine, forming a disulfide bridge with a concomitant decrease in the activity of the enzyme.
Collapse
Affiliation(s)
- Ramses Cruz-Valencia
- Centro de Investigación en Alimentación y Desarrollo A.C., Hermosillo, 83304, Sonora, México
| | - Aldo A Arvizu-Flores
- Departamento de Ciencias Químico-Biológicas, Universidad de Sonora, Hermosillo, 83000, Sonora, México
| | - Jesús A Rosas-Rodríguez
- Departamento de Ciencias, Químico Biológicas y Agropecuarias, Universidad de Sonora Unidad Regional Sur, Navojoa, 85880, Sonora, México
| | - Elisa M Valenzuela-Soto
- Centro de Investigación en Alimentación y Desarrollo A.C., Hermosillo, 83304, Sonora, México.
| |
Collapse
|
4
|
Vetica F, Sansone A, Meliota C, Batani G, Roberti M, Chatgilialoglu C, Ferreri C. Free-Radical-Mediated Formation of Trans-Cardiolipin Isomers, Analytical Approaches for Lipidomics and Consequences of the Structural Organization of Membranes. Biomolecules 2020; 10:biom10081189. [PMID: 32824246 PMCID: PMC7465319 DOI: 10.3390/biom10081189] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/01/2020] [Accepted: 08/12/2020] [Indexed: 12/27/2022] Open
Abstract
Free-radical-mediated processes, such as peroxidation, isomerization and hydrogenation affecting fatty acid integrity and biological functions, have a trans-disciplinary relevance. Cardiolipins (CL, (1,3-diphosphatidyl-sn-glycerol)) and tetra-linoleoyl-CL are complex phospholipids, exclusively present in the Inner Mitochondrial Membrane (IMM) lipids, where they maintain membrane integrity and regulate enzyme functionalities. Peroxidation pathways and fatty acid remodeling are known causes of mitochondrial disfunctions and pathologies, including cancer. Free-radical-mediated isomerization with the change of the cis CL into geometrical trans isomers is an unknown process with possible consequences on the supramolecular membrane lipid organization. Here, the formation of mono-trans CL (MT-CL) and other trans CL isomers (T-CL) is reported using CL from bovine heart mitochondria and thiyl radicals generated by UV-photolysis from 2-mercaptoethanol. Analytical approaches for CL isomer separation and identification via 1H/13C NMR are provided, together with the chemical study of CL derivatization to fatty acid methyl esters (FAME), useful for lipidomics and metabolomics research. Kinetics information of the radical chain isomerization process was obtained using γ-irradiation conditions. The CL isomerization affected the structural organization of membranes, as tested by the reduction in unilamellar liposome diameter, and accompanied the well-known process of oxidative consumption induced by Fenton reagents. These results highlight a potential new molecular modification pathway of mitochondrial lipids with wide applications to membrane functions and biological consequences.
Collapse
Affiliation(s)
- Fabrizio Vetica
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via Piero Gobetti 101, 40129 Bologna, Italy; (F.V.); (A.S.); (C.M.); (G.B.)
| | - Anna Sansone
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via Piero Gobetti 101, 40129 Bologna, Italy; (F.V.); (A.S.); (C.M.); (G.B.)
| | - Cesare Meliota
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via Piero Gobetti 101, 40129 Bologna, Italy; (F.V.); (A.S.); (C.M.); (G.B.)
| | - Gessica Batani
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via Piero Gobetti 101, 40129 Bologna, Italy; (F.V.); (A.S.); (C.M.); (G.B.)
| | - Marinella Roberti
- Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy;
| | - Chryssostomos Chatgilialoglu
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via Piero Gobetti 101, 40129 Bologna, Italy; (F.V.); (A.S.); (C.M.); (G.B.)
- Center for Advanced Technologies, Adam Mickiewicz University, 61-614 Poznań, Poland
- Correspondence: (C.C.); (C.F.)
| | - Carla Ferreri
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, Via Piero Gobetti 101, 40129 Bologna, Italy; (F.V.); (A.S.); (C.M.); (G.B.)
- Correspondence: (C.C.); (C.F.)
| |
Collapse
|
5
|
Choi JY, Black R, Lee H, Di Giovanni J, Murphy RC, Ben Mamoun C, Voelker DR. An improved and highly selective fluorescence assay for measuring phosphatidylserine decarboxylase activity. J Biol Chem 2020; 295:9211-9222. [PMID: 32430397 PMCID: PMC7335775 DOI: 10.1074/jbc.ra120.013421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/14/2020] [Indexed: 11/06/2022] Open
Abstract
Phosphatidylserine decarboxylases (PSDs) catalyze the conversion of phosphatidylserine (PS) to phosphatidylethanolamine (PE), a critical step in membrane biogenesis and a potential target for development of antimicrobial and anti-cancer drugs. PSD activity has typically been quantified using radioactive substrates and products. Recently, we described a fluorescence-based assay that measures the PSD reaction using distyrylbenzene-bis-aldehyde (DSB-3), whose reaction with PE produces a fluorescence signal. However, DSB-3 is not widely available and also reacts with PSD's substrate, PS, producing an adduct with lower fluorescence yield than that of PE. Here, we report a new fluorescence-based assay that is specific for PSD and in which the presence of PS causes only negligible background. This new assay uses 1,2-diacetyl benzene/β-mercaptoethanol, which forms a fluorescent iso-indole-mercaptide conjugate with PE. PE detection with this method is very sensitive and comparable with detection by radiochemical methods. Model reactions examining adduct formation with ethanolamine produced stable products of exact masses (m/z) of 342.119 and 264.105. The assay is robust, with a signal/background ratio of 24, and can readily detect formation of 100 pmol of PE produced from Escherichia coli membranes, Candida albicans mitochondria, or HeLa cell mitochondria. PSD activity can easily be quantified by sequential reagent additions in 96- or 384-well plates, making it readily adaptable to high-throughput screening for PSD inhibitors. This new assay now enables straightforward large-scale screening for PSD inhibitors against pathogenic fungi, antibiotic-resistant bacteria, and neoplastic mammalian cells.
Collapse
Affiliation(s)
- Jae-Yeon Choi
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - Raymond Black
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - HeeJung Lee
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA
| | - James Di Giovanni
- Department of Pharmacology, University of Colorado Denver, Aurora, Colorado, USA
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, Colorado, USA
| | - Choukri Ben Mamoun
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Dennis R Voelker
- Basic Science Section, Department of Medicine, National Jewish Health, Denver, Colorado, USA.
| |
Collapse
|
6
|
Gopal A, Herr AE. Multiplexed in-gel microfluidic immunoassays: characterizing protein target loss during reprobing of benzophenone-modified hydrogels. Sci Rep 2019; 9:15389. [PMID: 31659305 PMCID: PMC6817870 DOI: 10.1038/s41598-019-51849-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/27/2019] [Indexed: 12/28/2022] Open
Abstract
From whole tissues to single-cell lysate, heterogeneous immunoassays are widely utilized for analysis of protein targets in complex biospecimens. Recently, benzophenone-functionalized hydrogel scaffolds have been used to immobilize target protein for immunoassay detection with fluorescent antibody probes. In benzophenone-functionalized hydrogels, multiplex target detection occurs via serial rounds of chemical stripping (incubation with sodium-dodecyl-sulfate (SDS) and β-mercaptoethanol at 50-60 °C for ≥1 h), followed by reprobing (interrogation with additional antibody probes). Although benzophenone facilitates covalent immobilization of proteins to the hydrogel, we observe 50% immunoassay signal loss of immobilized protein targets during stripping rounds. Here, we identify and characterize signal loss mechanisms during stripping and reprobing. We posit that loss of immobilized target is responsible for ≥50% of immunoassay signal loss, and that target loss is attributable to disruption of protein immobilization by denaturing detergents (SDS) and incubation at elevated temperatures. Furthermore, our study suggests that protein losses under non-denaturing conditions are more sensitive to protein structure (i.e., hydrodynamic radius), than to molecular mass (size). We formulate design guidance for multiplexed in-gel immunoassays, including that low-abundance proteins be immunoprobed first, even when targets are covalently immobilized to the gel. We also recommend careful scrutiny of the order of proteins targets detected via multiple immunoprobing cycles, based on the protein immobilization buffer composition.
Collapse
Affiliation(s)
- Anjali Gopal
- Department of Bioengineering, University of California, Berkeley, Berkeley, California, 94720, United States
- UC Berkeley/UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California, 94720, United States
| | - Amy E Herr
- Department of Bioengineering, University of California, Berkeley, Berkeley, California, 94720, United States.
- UC Berkeley/UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California, 94720, United States.
- Chan Zuckerberg BioHub, San Francisco, California, 94158, United States.
| |
Collapse
|
7
|
Sawicki A, Willows RD, Chen M. Spectral signatures of five hydroxymethyl chlorophyll a derivatives chemically derived from chlorophyll b or chlorophyll f. Photosynth Res 2019; 140:115-127. [PMID: 30604202 DOI: 10.1007/s11120-018-00611-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 12/17/2018] [Indexed: 06/09/2023]
Abstract
Chlorophylls (Chls) are pigments involved in light capture and light reactions in photosynthesis. Chl a, Chl b, Chl d, and Chl f are characterized by unique absorbance maxima in the blue (Soret) and red (Qy) regions with Chl b, Chl d, and Chl f each possessing a single formyl group at a unique position. Relative to Chl a the Qy absorbance maximum of Chl b is blue-shifted while Chl d and Chl f are red-shifted with the shifts attributable to the relative positions of the formyl substitutions. Reduction of a formyl group of Chl b to form 7-hydroxymethyl Chl a, or oxidation of the vinyl group of Chl a into a formyl group to form Chl d was achieved using sodium borohydride (NaBH4) or β-mercaptoethanol (BME/O2), respectively. During the consecutive reactions of Chl b and Chl f using a three-step procedure (1. NaBH4, 2. BME/O2, and 3. NaBH4) two new 7-hydroxymethyl Chl a species were prepared possessing the 3-formyl or 3-hydroxymethyl groups and three new 2-hydroxymethyl Chl a species possessing the 3-vinyl, 3-formyl, or 3-hydroxymethyl groups, respectively. Identification of the spectral properties of 2-hydroxymethyl Chl a may be biologically significant for deducing the latter stages of Chl f biosynthesis if the mechanism parallels Chl b biosynthesis. The spectral features and chromatographic properties of these modified Chls are important for identifying potential intermediates in the biosynthesis of Chls such as Chl f and Chl d and for identification of any new Chls in nature.
Collapse
Affiliation(s)
- Artur Sawicki
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, 2006, Australia
| | - Robert D Willows
- Department of Molecular Sciences, Macquarie University, Sydney, NSW, 2019, Australia
| | - Min Chen
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, 2006, Australia.
| |
Collapse
|
8
|
Hande M, Maity S, Lönnberg T. Palladacyclic Conjugate Group Promotes Hybridization of Short Oligonucleotides. Int J Mol Sci 2018; 19:ijms19061588. [PMID: 29843368 PMCID: PMC6032164 DOI: 10.3390/ijms19061588] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 11/16/2022] Open
Abstract
Short oligonucleotides with cyclopalladated benzylamine moieties at their 5'-termini have been prepared to test the possibility of conferring palladacyclic anticancer agents sequence-selectivity by conjugation with a guiding oligonucleotide. Hybridization of these oligonucleotides with natural counterparts was studied by UV and CD (circular dichroism) melting experiments in the absence and presence of a competing ligand (2-mercaptoethanol). Cyclopalladated benzylamine proved to be strongly stabilizing relative to unmetalated benzylamine and modestly stabilizing relative to an extra A•T base pair. The stabilization was largely abolished in the presence of 2-mercaptoethanol, suggesting direct coordination of Pd(II) to a nucleobase of the complementary strand. In all cases, fidelity of Watson-Crick base pairing between the two strands was retained. Hybridization of the cyclopalladated oligonucleotides was characterized by relatively large negative enthalpy and entropy, consistent with stabilizing Pd(II) coordination partially offset by the entropic penalty of imposing conformational constraints on the flexible diethylene glycol linker between the oligonucleotide and the palladacyclic moiety.
Collapse
Affiliation(s)
- Madhuri Hande
- Department of Chemistry, University of Turku, Vatselankatu 2, 20014 Turku, Finland.
| | - Sajal Maity
- Department of Chemistry, University of Turku, Vatselankatu 2, 20014 Turku, Finland.
| | - Tuomas Lönnberg
- Department of Chemistry, University of Turku, Vatselankatu 2, 20014 Turku, Finland.
| |
Collapse
|
9
|
Karfo R, Kabré E, Safir N, Bouabdellah M, Benchekroun L, Sakandé J, Chabraoui L. Interprétation délicate de l'immunofixation des protéines sériques. Pan Afr Med J 2018; 30:130. [PMID: 30374376 PMCID: PMC6201619 DOI: 10.11604/pamj.2018.30.130.13662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 05/15/2018] [Indexed: 11/22/2022] Open
Abstract
L'immunofixation est actuellement très utilisée dans les laboratoires d'analyses médicales. L'interprétation des résultats est en général facile, mais il existe des cas qui posent des problèmes d'interprétation. Nous vous rapportons deux observations d'interprétation délicate. Dans la première observation, nous présentons un cas de précipitation non spécifique de la protéine sur toutes les pistes, dans la deuxième observation un cas présentant une double bande monoclonale à l'immunofixation. Pour ces deux observations, l'utilisation de la solution réductrice de β2-mercaptoéthanol nous a permis de résoudre le problème et de conclure à un diagnostic. La confrontation des données cliniques, radiologiques et biologiques est nécessaire avant de conclure à une immunoglobuline monoclonale.
Collapse
Affiliation(s)
- Raoul Karfo
- Service du Laboratoire Central de Biochimie, Centre Hospitalier Universitaire Ibn Sina, Maroc
- Unité de Formation et de Recherche en Sciences de la Santé, Université Ouaga I Pr Joseph Ki-Zerbo, Burkina Faso
- Clinique du Laboratoire de Biologie, Centre Médical du Camp General Aboubacar Sangoulé Lamizana, Ouagadougou, Burkina Faso
| | - Elie Kabré
- Unité de Formation et de Recherche en Sciences de la Santé, Université Ouaga I Pr Joseph Ki-Zerbo, Burkina Faso
- Laboratoire de Biochimie, Centre Hospitalier Universitaire Yalgado Ouedraogo, Ouagadougou, Burkina Faso
| | - Nadia Safir
- Service du Laboratoire Central de Biochimie, Centre Hospitalier Universitaire Ibn Sina, Maroc
- UFR de Chimie Biochimie et Biologie Moléculaire, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Mounya Bouabdellah
- Service du Laboratoire Central de Biochimie, Centre Hospitalier Universitaire Ibn Sina, Maroc
- UFR de Chimie Biochimie et Biologie Moléculaire, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Laila Benchekroun
- Service du Laboratoire Central de Biochimie, Centre Hospitalier Universitaire Ibn Sina, Maroc
- UFR de Chimie Biochimie et Biologie Moléculaire, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| | - Jean Sakandé
- Unité de Formation et de Recherche en Sciences de la Santé, Université Ouaga I Pr Joseph Ki-Zerbo, Burkina Faso
- Laboratoire de Biochimie, Centre Hospitalier Universitaire Yalgado Ouedraogo, Ouagadougou, Burkina Faso
| | - Layachi Chabraoui
- Service du Laboratoire Central de Biochimie, Centre Hospitalier Universitaire Ibn Sina, Maroc
- UFR de Chimie Biochimie et Biologie Moléculaire, Faculté de Médecine et de Pharmacie, Université Mohammed V, Rabat, Maroc
| |
Collapse
|
10
|
Cloin BMC, De Zitter E, Salas D, Gielen V, Folkers GE, Mikhaylova M, Bergeler M, Krajnik B, Harvey J, Hoogenraad CC, Van Meervelt L, Dedecker P, Kapitein LC. Efficient switching of mCherry fluorescence using chemical caging. Proc Natl Acad Sci U S A 2017; 114:7013-7018. [PMID: 28630286 PMCID: PMC5502588 DOI: 10.1073/pnas.1617280114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Fluorophores with dynamic or controllable fluorescence emission have become essential tools for advanced imaging, such as superresolution imaging. These applications have driven the continuing development of photoactivatable or photoconvertible labels, including genetically encoded fluorescent proteins. These new probes work well but require the introduction of new labels that may interfere with the proper functioning of existing constructs and therefore require extensive functional characterization. In this work we show that the widely used red fluorescent protein mCherry can be brought to a purely chemically induced blue-fluorescent state by incubation with β-mercaptoethanol (βME). The molecules can be recovered to the red fluorescent state by washing out the βME or through irradiation with violet light, with up to 80% total recovery. We show that this can be used to perform single-molecule localization microscopy (SMLM) on cells expressing mCherry, which renders this approach applicable to a very wide range of existing constructs. We performed a detailed investigation of the mechanism underlying these dynamics, using X-ray crystallography, NMR spectroscopy, and ab initio quantum-mechanical calculations. We find that the βME-induced fluorescence quenching of mCherry occurs both via the direct addition of βME to the chromophore and through βME-mediated reduction of the chromophore. These results not only offer a strategy to expand SMLM imaging to a broad range of available biological models, but also present unique insights into the chemistry and functioning of a highly important class of fluorophores.
Collapse
Affiliation(s)
- Bas M C Cloin
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Elke De Zitter
- Biochemistry, Molecular and Structural Biology, Department of Chemistry, KU Leuven, 3001 Heverlee, Belgium
| | - Desiree Salas
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Vincent Gielen
- Biochemistry, Molecular and Structural Biology, Department of Chemistry, KU Leuven, 3001 Heverlee, Belgium
| | - Gert E Folkers
- NMR Spectroscopy, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Marina Mikhaylova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Maike Bergeler
- Quantum Chemistry and Physical Chemistry, Department of Chemistry, KU Leuven, 3001 Heverlee, Belgium
| | - Bartosz Krajnik
- Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, 3001 Heverlee, Belgium
- Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University, 87-100 Torun, Poland
| | - Jeremy Harvey
- Quantum Chemistry and Physical Chemistry, Department of Chemistry, KU Leuven, 3001 Heverlee, Belgium
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Luc Van Meervelt
- Biochemistry, Molecular and Structural Biology, Department of Chemistry, KU Leuven, 3001 Heverlee, Belgium
| | - Peter Dedecker
- Biochemistry, Molecular and Structural Biology, Department of Chemistry, KU Leuven, 3001 Heverlee, Belgium;
| | - Lukas C Kapitein
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands;
| |
Collapse
|
11
|
Abstract
DNA is widely used in plant genetic and molecular biology studies. In this chapter, we describe how to extract DNA from wheat tissues. The tissue samples are ground to disrupt the cell wall. Then cetyltrimethylammonium bromide (CTAB) or sodium dodecyl sulfate (SDS) is used to disrupt the cell and nuclear membranes to release the DNA into solution. A reducing agent, β-mercaptoethanol, is added to break the disulfide bonds between the cysteine residues and to help remove the tanins and polyphenols. A high concentration of salt is employed to remove polysaccharides. Ethylenediaminetetraacetic acid (EDTA) stops DNase activity by chelating the magnesium ions. The nucleic acid solution is extracted with chloroform-isoamyl alcohol (24:1) or 6 M ammonium acetate. The DNA in aqueous phase is precipated with ethanol or isopropanol, which makes DNA less hydrophilic in the presence of sodium ions (Na+).
Collapse
Affiliation(s)
- Guotai Yu
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Asyraf Hatta
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
- Department of Agriculture Technology, Universiti Putra Malaysia, Serdang, Malaysia
| | - Sambasivam Periyannan
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD, Australia
- Plant Breeding Institute, University of Sydney, Sydney, NSW, Australia
- Agriculture & Food, CSIRO, Canberra, ACT, Australia
| | - Evans Lagudah
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | | |
Collapse
|
12
|
Kennedy E, Dong Z, Tennant C, Timp G. Reading the primary structure of a protein with 0.07 nm 3 resolution using a subnanometre-diameter pore. Nat Nanotechnol 2016; 11:968-976. [PMID: 27454878 DOI: 10.1038/nnano.2016.120] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 06/06/2016] [Indexed: 05/02/2023]
Abstract
The primary structure of a protein consists of a sequence of amino acids and is a key factor in determining how a protein folds and functions. However, conventional methods for sequencing proteins, such as mass spectrometry and Edman degradation, suffer from short reads and lack sensitivity, so alternative approaches are sought. Here, we show that a subnanometre-diameter pore, sputtered through a thin silicon nitride membrane, can be used to detect the primary structure of a denatured protein molecule. When a denatured protein immersed in electrolyte is driven through the pore by an electric field, measurements of a blockade in the current reveal nearly regular fluctuations, the number of which coincides with the number of residues in the protein. Furthermore, the amplitudes of the fluctuations are highly correlated with the volumes that are occluded by quadromers (four residues) in the primary structure. Each fluctuation, therefore, represents a read of a quadromer. Scrutiny of the fluctuations reveals that the subnanometre pore is sensitive enough to read the occluded volume that is related to post-translational modifications of a single residue, measuring volume differences of ∼0.07 nm3, but it is not sensitive enough to discriminate between the volumes of all twenty amino acids.
Collapse
Affiliation(s)
- Eamonn Kennedy
- Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Zhuxin Dong
- Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Clare Tennant
- Chemical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Gregory Timp
- Electrical Engineering and Biological Science, University of Notre Dame, Notre Dame, Indiana 46556, USA
| |
Collapse
|
13
|
Silva M, Rey V, Botana A, Vasconcelos V, Botana L. Determination of Gonyautoxin-4 in Echinoderms and Gastropod Matrices by Conversion to Neosaxitoxin Using 2-Mercaptoethanol and Post-Column Oxidation Liquid Chromatography with Fluorescence Detection. Toxins (Basel) 2015; 8:E11. [PMID: 26729166 PMCID: PMC4728533 DOI: 10.3390/toxins8010011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/14/2015] [Accepted: 12/24/2015] [Indexed: 11/27/2022] Open
Abstract
Paralytic Shellfish Toxin blooms are common worldwide, which makes their monitoring crucial in the prevention of poisoning incidents. These toxins can be monitored by a variety of techniques, including mouse bioassay, receptor binding assay, and liquid chromatography with either mass spectrometric or pre- or post-column fluorescence detection. The post-column oxidation liquid chromatography with fluorescence detection method, used routinely in our laboratory, has been shown to be a reliable method for monitoring paralytic shellfish toxins in mussel, scallop, oyster and clam species. However, due to its high sensitivity to naturally fluorescent matrix interferences, when working with unconventional matrices, there may be problems in identifying toxins because of naturally fluorescent interferences that co-elute with the toxin peaks. This can lead to erroneous identification. In this study, in order to overcome this challenge in echinoderm and gastropod matrices, we optimized the conversion of Gonyautoxins 1 and 4 to Neosaxitoxin with 2-mercaptoethanol. We present a new and less time-consuming method with a good recovery (82.2%, RSD 1.1%, n = 3), requiring only a single reaction step.
Collapse
Affiliation(s)
- Marisa Silva
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4619-007, Portugal.
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Rua dos Bragas, 289, Porto 4050-123, Portugal.
| | - Verónica Rey
- Department of Analytical Chemistry, Science Faculty, University of Santiago of Compostela, Lugo 27002, Spain.
| | - Ana Botana
- Department of Analytical Chemistry, Science Faculty, University of Santiago of Compostela, Lugo 27002, Spain.
| | - Vitor Vasconcelos
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, Porto 4619-007, Portugal.
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Rua dos Bragas, 289, Porto 4050-123, Portugal.
| | - Luis Botana
- Department of Pharmacology, Veterinary Faculty, University of Santiago de Compostela, Lugo 27002, Spain.
| |
Collapse
|
14
|
Sun A, Chen SL, Gao FT, Li HL, Liu XF, Wang N, Sha ZX. Establishment and characterization of a gonad cell line from half-smooth tongue sole Cynoglossus semilaevis pseudomale. Fish Physiol Biochem 2015; 41:673-83. [PMID: 25724869 DOI: 10.1007/s10695-015-0037-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/20/2015] [Indexed: 06/04/2023]
Abstract
A new cell line was established from half-smooth tongue sole Cynoglossus semilaevis pseudomale gonad (CSPMG). Primary culture was initiated from gonad tissues pieces, and the CSPMG cells were cultured at 24 °C in Dulbecco's modified Eagle medium/F12 medium (1:1) (pH7.0), supplemented with 20 % fetal bovine serum, basic fibroblast growth factor, epidermal growth factor, insulin-like growth factor-I, 2-mercaptoethanol, penicillin and streptomycin. The cultured CSPMG cells, in fibroblast shape, proliferated to 100 % confluency 10 days later and had been subcultured to passage 109. Chromosome analyses indicated that the CSPMG cells exhibited chromosomal aneuploidy with a modal chromosome number of 42, which displayed the normal diploid karyotype of half-smooth tongue sole (2n = 42t, NF = 42). Reverse transcription polymerase chain reaction revealed CSPMG cells could express gonad somatic cell functional genes Sox9a, Wt1a and weakly germ cell marker gene Vasa, but not male specific gene Dmrt1. Transfection experiment demonstrated that CSPMG cells transfected with pEGFP-N3 plasmid and small RNA could express green and red fluorescence signals with high transfection efficiency. In conclusion, a continuous CSPMG cell line has been established successfully. The cell line might serve as a valuable tool for studies on the mechanism of sex determination, sex reversal and gonad development in flatfish.
Collapse
Affiliation(s)
- Ai Sun
- Key Lab of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | | | | | | | | | | | | |
Collapse
|
15
|
Manjunath S, Satish Rao BS, Satyamoorthy K, Mahato KK. Laser induced autofluorescence in the monitoring of β-mercaptoethanol mediated photo induced proton coupled electron transfer in proteins. Spectrochim Acta A Mol Biomol Spectrosc 2015; 149:607-614. [PMID: 25985124 DOI: 10.1016/j.saa.2015.04.096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 03/18/2015] [Accepted: 04/22/2015] [Indexed: 06/04/2023]
Abstract
Photo induced proton coupled electron transfer (PCET) is an important process that many organisms use for progression of catalytic reactions leading to energy conversion. In the present study, the influence of SDS and BME on the redox properties of tyrosine and tryptophan for five different globular proteins, BSA, HSA, RNase-A, trypsin and lysozyme were studied using laser induced autofluorescence. The proteins were subjected to denaturation under SDS, SDS plus heat and SDS plus β-mercaptoethanol (BME) plus heat and the corresponding fluorescence were recorded. The influence of BME on the autofluorescence properties of the proteins were evaluated upon tris-2-corboxy-ethyl phosphine (TCEP) denaturation. The BSA and HSA when exposed to SDS alone, exhibited hydrophobic collapse around their tryptophan moieties. However, these proteins when treated with SDS plus BME plus heat, an unusual red shift in the emission was observed, may be due to proton transfer from hydroxyl group of the excited tyrosine residues to the local microenvironments. The observation was further confirmed with similar proton transfer in absence of tryptophan in RNase-A showing involvement of tyrosine in the process. A drastic quenching of fluorescence in all of the proteins under study were also observed, may be due to photo-induced electron transfer (PET) from BME to the intrinsic fluorophores resulting in radical ions formation, evaluated upon DCFDA measurements.
Collapse
Affiliation(s)
- S Manjunath
- Department of Biophysics, School of Life Sciences, Manipal University, Manipal, India
| | - B S Satish Rao
- Department of Radiation Biology and Toxicology, School of Life Sciences, Manipal University, Manipal, India
| | - K Satyamoorthy
- School of Life Sciences, Manipal University, Manipal 576104, Karnataka, India
| | - K K Mahato
- Department of Biophysics, School of Life Sciences, Manipal University, Manipal, India.
| |
Collapse
|
16
|
Abstract
The uridin-2'-yl radical (1) has been proposed as an intermediate during RNA oxidation. However, its reactivity has not been thoroughly studied due to the complex conditions under which it is typically generated. The uridin-2'-yl radical was independently generated from a benzyl ketone (2a) via Norrish type I photocleavage upon irradiation at λmax = 350 nm. Dioxygen and β-mercaptoethanol are unable to compete with loss of uracil from 1 in phosphate buffer. Thiol trapping competes with uracil fragmentation in less polar solvent conditions. This is ascribed mostly to a reduction in the rate constant for uracil elimination in the less polar solvent. Hydrogen atom transfer to 1 from β-mercaptoethanol occurs exclusively from the α-face to produce arabinouridine. Mass balances range from 72 to 95%. Furthermore, the synthesis of 2a is amenable to formation of the requisite phosphoramidite for solid-phase oligonucleotide synthesis. This and the fidelity with which the urdin-2'-yl radical is generated from 2a suggest that this precursor should be useful for studying the radical's reactivity in synthetic oligonucleotides.
Collapse
Affiliation(s)
- Rakesh Paul
- Department of Chemistry, Johns
Hopkins University 3400
North Charles Street, Baltimore, Maryland 21218, United
States
| | - Marc M. Greenberg
- Department of Chemistry, Johns
Hopkins University 3400
North Charles Street, Baltimore, Maryland 21218, United
States
| |
Collapse
|
17
|
Benedetto CD, Barbaglio A, Martinello T, Alongi V, Fassini D, Cullorà E, Patruno M, Bonasoro F, Barbosa MA, Carnevali MDC, Sugni M. Production, characterization and biocompatibility of marine collagen matrices from an alternative and sustainable source: the sea urchin Paracentrotus lividus. Mar Drugs 2014; 12:4912-33. [PMID: 25255130 PMCID: PMC4178497 DOI: 10.3390/md12094912] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 08/26/2014] [Accepted: 09/05/2014] [Indexed: 11/30/2022] Open
Abstract
Collagen has become a key-molecule in cell culture studies and in the tissue engineering field. Industrially, the principal sources of collagen are calf skin and bones which, however, could be associated to risks of serious disease transmission. In fact, collagen derived from alternative and riskless sources is required, and marine organisms are among the safest and recently exploited ones. Sea urchins possess a circular area of soft tissue surrounding the mouth, the peristomial membrane (PM), mainly composed by mammalian-like collagen. The PM of the edible sea urchin Paracentrotus lividus therefore represents a potential unexploited collagen source, easily obtainable as a food industry waste product. Our results demonstrate that it is possible to extract native collagen fibrils from the PM and produce suitable substrates for in vitro system. The obtained matrices appear as a homogeneous fibrillar network (mean fibril diameter 30-400 nm and mesh < 2 μm) and display remarkable mechanical properties in term of stiffness (146 ± 48 MPa) and viscosity (60.98 ± 52.07 GPa·s). In vitro tests with horse pbMSC show a good biocompatibility in terms of overall cell growth. The obtained results indicate that the sea urchin P. lividus can be a valuable low-cost collagen source for mechanically resistant biomedical devices.
Collapse
Affiliation(s)
| | - Alice Barbaglio
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milan, Italy.
| | - Tiziana Martinello
- Department of Comparative Biomedicine and Food Science, University of Padova, Agripolis Viale dell'Università 16, 35020 Legnaro (PD), Italy.
| | - Valentina Alongi
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milan, Italy.
| | - Dario Fassini
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milan, Italy.
| | - Emanuele Cullorà
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milan, Italy.
| | - Marco Patruno
- Department of Comparative Biomedicine and Food Science, University of Padova, Agripolis Viale dell'Università 16, 35020 Legnaro (PD), Italy.
| | - Francesco Bonasoro
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milan, Italy.
| | - Mario Adolfo Barbosa
- INEB-Institute of Biomedical Engineering, University of Porto, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal.
| | | | - Michela Sugni
- Department of Biosciences, University of Milan, Via Celoria 26, 20133 Milan, Italy.
| |
Collapse
|
18
|
Arimitsu H, Sasaki K, Kojima H, Yanaka T, Tsuji T. Simple method for Shiga toxin 2e purification by affinity chromatography via binding to the divinyl sulfone group. PLoS One 2013; 8:e83577. [PMID: 24340102 PMCID: PMC3858352 DOI: 10.1371/journal.pone.0083577] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 11/14/2013] [Indexed: 11/20/2022] Open
Abstract
Here we describe a simple affinity purification method for Shiga toxin 2e (Stx2e), a major causative factor of edema disease in swine. Escherichia coli strain MV1184 transformed with the expression plasmid pBSK-Stx2e produced Stx2e when cultivated in CAYE broth containing lincomycin. Stx2e bound to commercial D-galactose gel, containing α-D-galactose immobilized on agarose resin via a divinyl sulfone linker, and was eluted with phosphate-buffered saline containing 4.5 M MgCl2. A small amount of Stx2e bound to another commercial α-galactose-immobilized agarose resin, but not to β-galactose-immobilized resin. In addition, Stx2e bound to thiophilic adsorbent resin containing β-mercaptoethanol immobilized on agarose resin via a divinyl sulfone, and was purified in the same manner as from D-galactose gel, but the Stx2e sample contained some contamination. These results indicate that Stx2e bound to D-galactose gel mainly through the divinyl sulfone group on the resin and to a lesser extent through α-D-galactose. With these methods, the yields of Stx2e and attenuated mutant Stx2e (mStx2e) from 1 L of culture were approximately 36 mg and 27.7 mg, respectively, and the binding capacity of the D-galactose gel and thiophilic adsorbent resin for Stx2e was at least 20 mg per 1 ml of resin. In addition, using chimeric toxins with prototype Stx2 which did not bind to thiophilic adsorbent resin and some types of mutant Stx2e and Stx2 which contained inserted mutations in the B subunits, we found that, at the least, asparagine (amino acid 17 of the B subunits) was associated with Stx2e binding to the divinyl sulfone group. The mStx2e that was isolated exhibited vaccine effects in ICR mice, indicating that these methods are beneficial for large-scale preparation of Stx2e toxoid, which protects swine from edema disease.
Collapse
Affiliation(s)
- Hideyuki Arimitsu
- Department of Microbiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
- * E-mail:
| | - Keiko Sasaki
- Department of Microbiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Hiroe Kojima
- Advanced Technology Development Center, Kyoritsu Seiyaku Corporation, Tsukuba, Ibaraki, Japan
| | - Tadashi Yanaka
- Advanced Technology Development Center, Kyoritsu Seiyaku Corporation, Tsukuba, Ibaraki, Japan
| | - Takao Tsuji
- Department of Microbiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| |
Collapse
|
19
|
Wong CM, Marcocci L, Das D, Wang X, Luo H, Zungu-Edmondson M, Suzuki YJ. Mechanism of protein decarbonylation. Free Radic Biol Med 2013; 65:1126-1133. [PMID: 24044890 PMCID: PMC3859829 DOI: 10.1016/j.freeradbiomed.2013.09.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 09/08/2013] [Accepted: 09/10/2013] [Indexed: 12/21/2022]
Abstract
Ligand/receptor stimulation of cells promotes protein carbonylation that is followed by the decarbonylation process, which might involve thiol-dependent reduction (C.M. Wong et al., Circ. Res. 102:301-318; 2008). This study further investigated the properties of this protein decarbonylation mechanism. We found that the thiol-mediated reduction of protein carbonyls is dependent on heat-labile biologic components. Cysteine and glutathione were efficient substrates for decarbonylation. Thiols decreased the protein carbonyl content, as detected by 2,4-dinitrophenylhydrazine, but not the levels of malondialdehyde or 4-hydroxynonenal protein adducts. Mass spectrometry identified proteins that undergo thiol-dependent decarbonylation, which include peroxiredoxins. Peroxiredoxin-2 and -6 were carbonylated and subsequently decarbonylated in response to the ligand/receptor stimulation of cells. siRNA knockdown of glutaredoxin inhibited the decarbonylation of peroxiredoxin. These results strengthen the concept that thiol-dependent decarbonylation defines the kinetics of protein carbonylation signaling.
Collapse
Affiliation(s)
- Chi-Ming Wong
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Lucia Marcocci
- Department of Biochemical Sciences "A. Rossi Fanelli," Sapienza University of Rome, Rome, Italy
| | - Dividutta Das
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Xinhong Wang
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA; Department of Physiology and Pathophysiology, Fudan University Shanghai Medical College, Shanghai 200032, China
| | - Haibei Luo
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA
| | | | - Yuichiro J Suzuki
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20057, USA.
| |
Collapse
|
20
|
Budvytyte R, Valincius G, Niaura G, Voiciuk V, Mickevicius M, Stauffer H, Goh HZ, Shekhar P, Heinrich F, Shenoy S, Lösche M, Vanderah DJ. Structure and properties of tethered bilayer lipid membranes with unsaturated anchor molecules. Langmuir 2013; 29:8645-56. [PMID: 23745652 PMCID: PMC3753044 DOI: 10.1021/la401132c] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The self-assembled monolayers (SAMs) of new lipidic anchor molecule HC18 [Z-20-(Z-octadec-9-enyloxy)-3,6,9,12,15,18,22-heptaoxatetracont-31-ene-1-thiol] and mixed HC18/β-mercaptoethanol (βME) SAMs were studied by spectroscopic ellipsometry, contact angle measurements, reflection-absorption infrared spectroscopy, and electrochemical impedance spectroscopy (EIS) and were evaluated in tethered bilayer lipid membranes (tBLMs). Our data indicate that HC18, containing a double bond in the alkyl segments, forms highly disordered SAMs up to anchor/βME molar fraction ratios of 80/20 and result in tBLMs that exhibit higher lipid diffusion coefficients relative to those of previous anchor compounds with saturated alkyl chains, as determined by fluorescence correlation spectroscopy. EIS data shows the HC18 tBLMs, completed by rapid solvent exchange or vesicle fusion, form more easily than with saturated lipidic anchors, exhibit excellent electrical insulating properties indicating low defect densities, and readily incorporate the pore-forming toxin α-hemolysin. Neutron reflectivity measurements on HC18 tBLMs confirm the formation of complete tBLMs, even at low tether compositions and high ionic lipid compositions. Our data indicate that HC18 results in tBLMs with improved physical properties for the incorporation of integral membrane proteins (IMPs) and that 80% HC18 tBLMs appear to be optimal for practical applications such as biosensors where high electrical insulation and IMP/peptide reconstitution are imperative.
Collapse
Affiliation(s)
- Rima Budvytyte
- Institute of Biochemistry, Vilnius University, Vilnius, LT-08662, Lithuania
| | - Gintaras Valincius
- Institute of Biochemistry, Vilnius University, Vilnius, LT-08662, Lithuania
| | - Gediminas Niaura
- Institute of Biochemistry, Vilnius University, Vilnius, LT-08662, Lithuania
| | - Vladislava Voiciuk
- Institute of Biochemistry, Vilnius University, Vilnius, LT-08662, Lithuania
| | | | - Hilary Stauffer
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899
- Hood College, Frederick, MD 21701
| | - Haw-Zan Goh
- Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213
| | | | - Frank Heinrich
- Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - Siddharth Shenoy
- Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Mathias Lösche
- Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - David J. Vanderah
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899
- Institute for Bioscience and Biotechnology Research, Rockville, MD 20850
| |
Collapse
|
21
|
Zhou R, Stalder R, Xie D, Cao W, Zheng Y, Yang Y, Plaisant M, Holloway PH, Schanze KS, Reynolds JR, Xue J. Enhancing the efficiency of solution-processed polymer:colloidal nanocrystal hybrid photovoltaic cells using ethanedithiol treatment. ACS Nano 2013; 7:4846-4854. [PMID: 23668301 DOI: 10.1021/nn305823w] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Advances in colloidal inorganic nanocrystal synthesis and processing have led to the demonstration of organic-inorganic hybrid photovoltaic (PV) cells using low-cost solution processes from blends of conjugated polymer and colloidal nanocrystals. However, the performance of such hybrid PV cells has been limited due to the lack of control at the complex interfaces between the organic and inorganic hybrid active materials. Here we show that the efficiency of hybrid PV devices can be significantly enhanced by engineering the polymer-nanocrystal interface with proper chemical treatment. Using two different conjugated polymers, poly(3-hexylthiophene) (P3HT) and poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT), we show that treating the polymer:nanocrystal hybrid film in an ethanedithiol-containing acetonitrile solution can increase the efficiency of the hybrid PV devices by 30-90%, and a maximum power conversion efficiency of 5.2 ± 0.3% was obtained in the PCPDTBT:CdSe devices at 0.2 sun (AM 1.5G), which was slightly reduced to 4.7 ± 0.3% at 1 sun. The ethanedithiol treatment did not result in significant changes in the morphology and UV-vis optical absorption of the hybrid thin films; however, infrared absorption, NMR, and X-ray photoelectron spectroscopies revealed the effective removal of organic ligands, especially the charged phosphonic acid ligands, from the CdSe nanorod surface after the treatment, accompanied by the possible monolayer passivation of nanorod surfaces with Cd-thiolates. We attribute the hybrid PV cell efficiency increase upon the ethanedithiol treatment to the reduction in charge and exciton recombination sites on the nanocrystal surface and the simultaneous increase in electron transport through the hybrid film.
Collapse
Affiliation(s)
- Renjia Zhou
- Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611-6400, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Perez-Aguilar JM, Xi J, Matsunaga F, Cui X, Selling B, Saven JG, Liu R. A computationally designed water-soluble variant of a G-protein-coupled receptor: the human mu opioid receptor. PLoS One 2013; 8:e66009. [PMID: 23799068 PMCID: PMC3682944 DOI: 10.1371/journal.pone.0066009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 04/30/2013] [Indexed: 11/19/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) play essential roles in various physiological processes, and are widely targeted by pharmaceutical drugs. Despite their importance, studying GPCRs has been problematic due to difficulties in isolating large quantities of these membrane proteins in forms that retain their ligand binding capabilities. Creating water-soluble variants of GPCRs by mutating the exterior, transmembrane residues provides a potential method to overcome these difficulties. Here we present the first study involving the computational design, expression and characterization of water-soluble variant of a human GPCR, the human mu opioid receptor (MUR), which is involved in pain and addiction. An atomistic structure of the transmembrane domain was built using comparative (homology) modeling and known GPCR structures. This structure was highly similar to the subsequently determined structure of the murine receptor and was used to computationally design 53 mutations of exterior residues in the transmembrane region, yielding a variant intended to be soluble in aqueous media. The designed variant expressed in high yield in Escherichia coli and was water soluble. The variant shared structural and functionally related features with the native human MUR, including helical secondary structure and comparable affinity for the antagonist naltrexone (Kd = 65 nM). The roles of cholesterol and disulfide bonds on the stability of the receptor variant were also investigated. This study exemplifies the potential of the computational approach to produce water-soluble variants of GPCRs amenable for structural and functionally related characterization in aqueous solution.
Collapse
Affiliation(s)
- Jose Manuel Perez-Aguilar
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jin Xi
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Felipe Matsunaga
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Xu Cui
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Anesthesiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Bernard Selling
- Impact Biologicals Inc., Swarthmore, Pennsylvania, United States of America
| | - Jeffery G. Saven
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (RL); (JGS)
| | - Renyu Liu
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (RL); (JGS)
| |
Collapse
|
23
|
Rigobello-Masini M, Masini JC. Improvements in the separation capabilities of sequential injection chromatography: determination of intracellular dissolved free amino acid profiles in three taxonomic groups of microalgae. Phytochem Anal 2013; 24:224-229. [PMID: 23055332 DOI: 10.1002/pca.2402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 08/07/2012] [Accepted: 08/20/2012] [Indexed: 06/01/2023]
Abstract
INTRODUCTION Dissolved free amino acids (DFAA) in intracellular extracts of marine microalgae can be determined by sequential injection chromatography (SIC). This technique uses portable, low-cost instrumentation but its applications have been limited to short monolithic columns because of components not resistant to high pressures. OBJECTIVE To develop a SIC method for determination of DFAA by exploring an instrument modified to handle pressures of 1000 psi. METHOD The method was based on pre-column derivatisation of the amino acids with o-phthalaldehyde and 2-mercaptoethanol in borate buffer (pH 9.4), separation and fluorimetric detection (λ(excitation)= 340 and λ(emission)= 450 nm). Separation was achieved by stepwise gradient elution using six mobile phases. The first elution step used a mobile phase composed of methanol:tetrahydrofuran:10 mm phosphate buffer (pH 7.2) at a volumetric ratio of 8:1:91. Additional elution steps used mobile phases containing methanol and 10 mM phosphate buffer at ratios of 17.5:82.5, 25:75, 35:65, 50:50 and 65:35. RESULTS Nineteen chromatographic peaks were observed in a mixture of 20 amino acids. The only complete co-elution was between tryptophan and methionine. Detection limits varied from 0.10 µm for isoleucine to 1.5 µm for lysine. Recoveries from spiked extracts were between 84 and 131%. CONCLUSION Resolutions of the amino acid pairs glutamine and histidine, valine and phenylalanine, and isoleucine and leucine were 1.5, 0.75 and 1.3, respectively. The proposed method found different profiles of DFAA among the three species of algae, suggesting its adequacy for metabolic studies.
Collapse
|
24
|
Jansen J, Ghaffar A, van der Horst TNS, Mihov G, van der Wal S, Feijen J, Grijpma DW. Controlling the kinetic chain length of the crosslinks in photo-polymerized biodegradable networks. J Mater Sci Mater Med 2013; 24:877-888. [PMID: 23371770 DOI: 10.1007/s10856-013-4873-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 01/18/2013] [Indexed: 06/01/2023]
Abstract
Biodegradable polymer networks were prepared by photo-initiated radical polymerization of methacrylate functionalized poly(D,L-lactide) oligomers. The kinetic chains formed in this radical polymerization are the multifunctional crosslinks of the networks. These chains are carbon-carbon chains that remain after degradation. If their molecular weight is too high these poly(methacrylic acid) chains can not be excreted by the kidneys. The effect of the photo-initiator concentration and the addition of 2-mercaptoethanol as a chain transfer agent on the molecular weight of the kinetic chains was investigated. It was found that both increasing the initiator concentration and adding 2-mercaptoethanol decrease the kinetic chain length. However, the effect of adding 2-mercaptoethanol was much larger. Some network properties such as the glass transition temperature and the swelling ratio in acetone are affected when the kinetic chain length is decreased.
Collapse
Affiliation(s)
- Janine Jansen
- Department of Biomaterials Science and Technology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
Although it is well recognized that the conformation state of a protein affects its surface properties, the importance of conformation flexibility to its functionality is still not well understood. This study systemically investigated the influence of protein concentration (c) and disulfide bond (S-S) cleavage with a reducing agent, β-mercaptoethanol (2-ME), on the conformation and emulsifying properties of an ideal globular protein, bovine serum albumin (BSA), with the aim to unravel the role of conformational flexibility in the functionality. The conformations were evaluated using size exclusion chromatography, dynamic light scattering (DLS), extrinsic fluorescence, and derivative UV spectroscopy. The emulsifying properties, including emulsifying ability, extent of droplet flocculation at a specific period of storage, and stability against flocculation and/or coalescence as well as creaming, were characterized using droplet size and creaming index analyses. The results indicated that the tertiary conformation of native BSA was closely dependent on its c (in the range of 0.05-1.0%), and increasing c resulted in a more compacted and rigid conformation. The c dependence largely determined the susceptibility of S-S bridges to reduction and even refolding of reduced BSA molecules. Interestingly, there was approximately a critical c (e.g., 0.25-0.5%) below which the S-S cleavage resulted in a gradual structural unfolding of the molecules and above which the situation was the reverse. On the other hand, the alteration with protein and 2-ME concentrations led to a variety of changes in emulsion size (d4,3; in water or 1% SDS) at 4 and 24 h and creaming index (up to 2 weeks). In general, at a low c value (e.g., 0.25%) increasing the S-S cleavage progressively improved the emulsifying ability and emulsion stability (especially against coalescence and creaming), whereas at c = 0.5 or 0.75%, the S-S cleavage, on the contrary, impaired the emulsifying properties, especially emulsion stability against flocculation and/or coalescence. These results suggest that the conformational flexibility of the protein (in solution) plays a vital role in different aspects of its emulsifying properties, for example, ease of structural unfolding at the interface, lateral interactions between adsorbed proteins, and formation of a viscoelastic interfacial layer (or multilayers). This knowledge could provide an in-depth understanding of the relationships between tertiary conformational flexibility and emulsifying properties of globular proteins.
Collapse
Affiliation(s)
- Chuan-He Tang
- Department of Food Science and Technology, South China University of Technology , Guangzhou 510640, People's Republic of China.
| | | |
Collapse
|
26
|
Abstract
Lignins are used often in formulations involving proteins but little is known about the surface interactions between these important biomacromolecules. In this work, we investigate the interactions at the solid-liquid interface of lignin with the two main proteins in soy, glycinin (11S) and β-conglycinin (7S). The extent of adsorption of 11S and 7S onto lignin films and the degree of hydration of the interfacial layers is quantified via Quartz crystal microgravimetry (QCM) and surface plasmon resonance (SPR). Solution ionic strength and protein denaturation (2-mercaptoethanol and urea) critically affect the adsorption process as protein molecules undergo conformational changes and their hydrophobic or hydrophilic amino acid residues interact with the surrounding medium. In general, the adsorption of the undenatured proteins onto lignin is more extensive compared to that of the denatured biomolecules and a large amount of water is coupled to the adsorbed molecules. The reduction in water contact angle after protein adsorption (by ~40° and 35° for undenatured 11S and 7S, respectively) is explained by strong nonspecific interactions between soy proteins and lignin.
Collapse
Affiliation(s)
- Carlos Salas
- Department of Forest Biomaterials, North Carolina State University, Raleigh, North Carolina 27695, United States
| | | | | | | | | |
Collapse
|
27
|
Georgin M, Carlini L, Cooper D, Bradforth SE, Nadeau JL. Differential effects of β-mercaptoethanol on CdSe/ZnS and InP/ZnS quantum dots. Phys Chem Chem Phys 2013; 15:10418-28. [PMID: 23681155 DOI: 10.1039/c3cp50311a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Marcel Georgin
- Department of Biomedical Engineering, McGill University, Montreal, QC H3A 2B4, Canada
| | | | | | | | | |
Collapse
|
28
|
Katsube-Tanaka T. Capillary electrophoresis of seed storage proteins: the separation and identification of microheterogeneous rice glutelin subunits. Methods Mol Biol 2013; 984:253-261. [PMID: 23386349 DOI: 10.1007/978-1-62703-296-4_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Glutelin, the major seed storage protein of rice (Oryza sativa L.), consists of multiple polymeric and monomeric subunits. Each subunit is composed of an α and a β polypeptide that are covalently linked by a disulfide bond. To analyze the microheterogeneous glutelin subunits using capillary electrophoresis (CE), the author identified the appropriate sample preparation procedures as well as optimal CE conditions. The glutelin was dissociated into its component α and β polypeptides by denaturation and reduction with low urea and 2-mercaptoethanol for a long incubation time at room temperature. The molecular species of the completely dissociated α and β polypeptides were identified and quantitatively analyzed by CE and SDS-PAGE using glutelin mutants. The measured CE migration times of the polypeptides correlated well with the calculated charge-to-size parameter values. Therefore, the rapid, simple, and precise separation and quantification of microheterogeneous proteins by CE required not only optimal CE conditions but also adequate protein pretreatment based on the molecular nature of the protein tested.
Collapse
|
29
|
Nadarajah A, Smith T, Könenkamp R. Improved performance of nanowire-quantum-dot-polymer solar cells by chemical treatment of the quantum dot with ligand and solvent materials. Nanotechnology 2012; 23:485403. [PMID: 23129022 DOI: 10.1088/0957-4484/23/48/485403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report a nanowire-quantum-dot-polymer solar cell consisting of a chemically treated CdSe quantum dot film deposited on n-type ZnO nanowires. The electron and hole collecting contacts are a fluorine-doped tin-oxide/zinc oxide layer and a P3HT/Au layer. This device architecture allows for enhanced light absorption and an efficient collection of photogenerated carriers. A detailed analysis of the chemical treatment of the quantum dots, their deposition, and the necessary annealing processes are discussed. We find that the surface treatment of CdSe quantum dots with pyridine, and the use of 1,2-ethanedithiol (EDT) ligands, critically improves the device performance. Annealing at 380 °C for 2 h is found to cause a structural conversion of the CdSe from its initial isolated quantum dot arrangement into a polycrystalline film with excellent surface conformality, thereby resulting in a further enhancement of device performance. Moreover, long-term annealing of 24 h leads to additional increases in device efficiency. Our best conversion efficiency reached for this type of cell is 3.4% under 85 mW cm(-2) illumination.
Collapse
Affiliation(s)
- A Nadarajah
- Department of Physics, Portland State University, Portland, OR 97201, USA.
| | | | | |
Collapse
|
30
|
Eliasen R, Andresen TL, Conde-Frieboes KW. Handling a tricycle: orthogonal versus random oxidation of the tricyclic inhibitor cystine knotted peptide gurmarin. Peptides 2012; 37:144-9. [PMID: 22771618 DOI: 10.1016/j.peptides.2012.06.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 06/26/2012] [Accepted: 06/26/2012] [Indexed: 11/22/2022]
Abstract
Gurmarin is a 35 amino acid peptide with three disulfide bridges in an inhibitor cystine knot. It is found in the plant Gymnema sylvestre, and has been identified as a sweet taste inhibitor in rodents. In this article we provide an efficient route for the synthesis of gurmarin by a controlled random oxidation strategy. We compared two oxidation procedures to form the three disulfide bridges. In the first, based on random oxidation, reduced gurmarin was synthesized using trityl for cysteine protection, and oxidized for 48 h in a Tris-HCl buffer containing cystamine and reduced glutathione to facilitate disulfide scrambling. The second was based on step-wise deprotection followed by oxidation in which the cysteine pairs are orthogonally protected with tert-Butylthio, trityl and acetamidomethyl. To verify that the native gurmarin oxidation product was obtained, thermolysin cleavage was used. Cleavage of random oxidized gurmarin showed two possible disulfide combinations; the native and a non-native gurmarin disulfide isomer. The non-native isomer was therefore synthesized using the orthogonal deprotection-oxidation strategy and the native and the non-native gurmarin isomers were analyzed using UPLC. It was found that the random oxidation procedure leads to native gurmarin in high yield. Thus, the synthetic route was simple and significantly more efficient than previously reported syntheses of gurmarin and other cysteine rich peptides. Importantly, native gurmarin was obtained by random oxidation, which was confirmed by a synthetic approach for the first time.
Collapse
Affiliation(s)
- Rasmus Eliasen
- Novo Nordisk A/S, Novo Nordisk Park, 2760 Måløv, Denmark
| | | | | |
Collapse
|
31
|
Gudzenko OV, Varbanets' LD. [Investigation of functional groups of Cryptococcus albidus alpha-L-rhamnosidase]. Mikrobiol Z 2012; 74:19-28. [PMID: 23088096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The effect of cations, anions and specific chemical reagents: 1-[3-(dimethylamino)propyl]-3-ethylcarbodimide methiodide, EDTA, o-phenantroline, dithiotreitol, L-cysteine, beta-mercaptoethanol, p-chlormercurybenzoate (p-ChMB), N-ethylmaleimide on the alpha-L-rhamnosidase activity of Cryptococcus albidus has been investigated. The essential role of Ag+ which inhibits the alpha-L-rhamnosidase activity by 72.5% was shown. Rhamnose at 1-5 mM protect the enzyme from the negative effect of Ag(+). It was expected that carboxyl group of C-terminal aminoacid and imidazole group of histidine would participate in the catalytic action of alpha-L-rhamnosidase on the basis of inhibition and kinetic analysis.
Collapse
|
32
|
Dixon DP, Sellars JD, Kenwright AM, Steel PG. The maize benzoxazinone DIMBOA reacts with glutathione and other thiols to form spirocyclic adducts. Phytochemistry 2012; 77:171-8. [PMID: 22342783 DOI: 10.1016/j.phytochem.2012.01.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 01/20/2012] [Accepted: 01/23/2012] [Indexed: 05/23/2023]
Abstract
Maize, wheat and other grasses synthesise large quantities of benzoxazinones and their glucosides, which act as antifeedant and allelopathic agents. These activities are probably due to the electrophilic nature of the aglycones, however, the mechanism of their action is unclear. In biological systems, glutathione (GSH) is the major electrophile-reactive compound so the reaction of the major maize benzoxazinone DIMBOA with GSH was studied. GSH reacts with DIMBOA to form eight isomeric mono-conjugates and eight isomeric di-conjugates. Through NMR studies with the model thiol 2-mercaptoethanol, these were structurally elucidated as unusual spirocycles. Similar reactivity was observed with proteins, with cysteinyl thiols being modified by DIMBOA. The thioether bonds formed were stable and not easily reduced to the parent thiol. DIMBOA can therefore readily deplete GSH levels and irreversibly inactivate enzymes with active-site cysteine residues, with clear implications for potentially toxic effects when young grasses are ingested, whether by insect pests or humans.
Collapse
Affiliation(s)
- David P Dixon
- Biophysical Sciences Institute, Durham University, Durham DH1 3LE, UK.
| | | | | | | |
Collapse
|
33
|
Deng K, Huang Y, Hua Y. Isolation of glycinin (11S) from lipid-reduced soybean flour: effect of processing conditions on yields and purity. Molecules 2012; 17:2968-79. [PMID: 22406901 PMCID: PMC6268596 DOI: 10.3390/molecules17032968] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/27/2012] [Accepted: 03/05/2012] [Indexed: 11/25/2022] Open
Abstract
Defatted soybean flour was treated with hexane and ethanol to reduce lipid content and heated to inactivate lipoxygenase (LOX, linoleate:oxygen reductase; EC 1.13.11.12) to obtain lipid-reduced soybean flour (LRSF). The effects of processing conditions such as pH, reducing agent and storage time on yields and purity of glycinin (11S) were evaluated in the fractionation of soybean glycinin isolated from LRSF. Adjusting the pH of protein extract from 6.2 to 6.6, the yield of glycinin decreased by 16.71%, while the purity of the protein increased by 4.60%. Sulfhydryl and disulfide content of proteins increased by degrees with increasing pH. Compared with dithiothreitol (DTT) or β-mercaptoethanol (ME) as reducing agent, the yield of glycinin was the highest when sodium bisulfite (SBS) was added to the protein extract at pH 6.4. The effect of DTT on yields of glycinin was the lowest of the three kinds of reducing agent. The purity of glycinin was similar when the three kinds of reducing agent were used. These results showed that SBS was the best choice for the isolation of 11S-rich fraction. Prolonging storage time in the precipitation stage, 10 h was the best for yields and purity of glycinin in the experiment, while there was no significant difference at P ≥ 0.05 for total sulfhydryl and disulfide content. The decreased free sulfhydryl content of glycinin indicated that the oxidation of free sulfhydryls and the formation of disulfide bonds occurred when the extraction time was prolonged.
Collapse
Affiliation(s)
- Kequan Deng
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu, China;
| | - Youru Huang
- School of Biological Science and Food Engineering, Changshu Institute of Technology, Changshu 215500, Jiangsu, China;
| | - Yufei Hua
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu, China;
| |
Collapse
|
34
|
Fu X, Lou T, Chen Z, Lin M, Feng W, Chen L. "Turn-on" fluorescence detection of lead ions based on accelerated leaching of gold nanoparticles on the surface of graphene. ACS Appl Mater Interfaces 2012; 4:1080-1086. [PMID: 22264012 DOI: 10.1021/am201711j] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A novel platform for effective "turn-on" fluorescence sensing of lead ions (Pb(2+)) in aqueous solution was developed based on gold nanoparticle (AuNP)-functionalized graphene. The AuNP-functionalized graphene exhibited minimal background fluorescence because of the extraordinarily high quenching ability of AuNPs. Interestingly, the AuNP-functionalized graphene underwent fluorescence restoration as well as significant enhancement upon adding Pb(2+), which was attributed to the fact that Pb(2+) could accelerate the leaching rate of the AuNPs on graphene surfaces in the presence of both thiosulfate (S(2)O(3)(2-)) and 2-mercaptoethanol (2-ME). Consequently, this could be utilized as the basis for selective detection of Pb(2+). With the optimum conditions chosen, the relative fluorescence intensity showed good linearity versus logarithm concentration of Pb(2+) in the range of 50-1000 nM (R = 0.9982), and a detection limit of 10 nM. High selectivity over common coexistent metal ions was also demonstrated. The practical application had been carried out for determination of Pb(2+) in tap water and mineral water samples. The Pb(2+)-specific "turn-on" fluorescence sensor, based on Pb(2+) accelerated leaching of AuNPs on the surface of graphene, provided new opportunities for highly sensitive and selective Pb(2+) detection in aqueous media.
Collapse
Affiliation(s)
- Xiuli Fu
- Key Laboratory of Coastal Zone Environmental Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
| | | | | | | | | | | |
Collapse
|
35
|
Seo J, Cho MJ, Lee D, Cartwright AN, Prasad PN. Efficient heterojunction photovoltaic cell utilizing nanocomposites of lead sulfide nanocrystals and a low-bandgap polymer. Adv Mater 2011; 23:3984-3988. [PMID: 21786344 DOI: 10.1002/adma.201101912] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 06/10/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Jangwon Seo
- Institute for Lasers, Photonics and Biophotonics, Department of Chemistry, State University of New York, Buffalo, NY 14260, USA
| | | | | | | | | |
Collapse
|
36
|
Sá O, Pereira JA, Baptista P. Optimization of DNA extraction for RAPD and ISSR analysis of Arbutus unedo L. Leaves. Int J Mol Sci 2011; 12:4156-64. [PMID: 21747730 PMCID: PMC3131614 DOI: 10.3390/ijms12064156] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 06/16/2011] [Accepted: 06/20/2011] [Indexed: 11/16/2022] Open
Abstract
Genetic analysis of plants relies on high yields of pure DNA. For the strawberry tree (Arbutus unedo) this represents a great challenge since leaves can accumulate large amounts of polysaccharides, polyphenols and secondary metabolites, which co-purify with DNA. For this specie, standard protocols do not produce efficient yields of high-quality amplifiable DNA. Here, we present for the first time an improved leaf-tissue protocol, based on the standard cetyl trimethyl ammonium bromide protocol, which yields large amounts of high-quality amplifiable DNA. Key steps in the optimized protocol are the addition of antioxidant compounds—namely polyvinyl pyrrolidone (PVP), 1,4-dithiothreitol (DTT) and 2-mercaptoethanol, in the extraction buffer; the increasing of CTAB (3%, w/v) and sodium chloride (2M) concentration; and an extraction with organic solvents (phenol and chloroform) with the incubation of samples on ice. Increasing the temperature for cell lyses to 70 °C also improved both DNA quality and yield. The yield of DNA extracted was 200.0 ± 78.0 μg/μL and the purity, evaluated by the ratio A260/A280, was 1.80 ± 0.021, indicative of minimal levels of contaminating metabolites. The quality of the DNA isolated was confirmed by random amplification polymorphism DNA and by inter-simple sequence repeat amplification, proving that the DNA can be amplified via PCR.
Collapse
Affiliation(s)
- Olga Sá
- Mountain Research Centre, School of Agriculture, Polytechnic Institute of Bragança, Campus St Apolónia, Apartado 1172, 5301-855, Bragança, Portugal; E-Mails: (O.S.); (J.A.P.)
| | | | | |
Collapse
|
37
|
Stankus DP, Lohse SE, Hutchison JE, Nason JA. Interactions between natural organic matter and gold nanoparticles stabilized with different organic capping agents. Environ Sci Technol 2011; 45:3238-3244. [PMID: 21162562 DOI: 10.1021/es102603p] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The adsorption of natural organic matter (NOM) to the surfaces of natural colloids and engineered nanoparticles is known to strongly influence, and in some cases control, their surface properties and aggregation behavior. As a result, the understanding of nanoparticle fate, transport, and toxicity in natural systems must include a fundamental framework for predicting such behavior. Using a suite of gold nanoparticles (AuNPs) with different capping agents, the impact of surface functionality, presence of natural organic matter, and aqueous chemical composition (pH, ionic strength, and background electrolytes) on the surface charge and colloidal stability of each AuNP type was investigated. Capping agents used in this study were as follows: anionic (citrate and tannic acid), neutral (2,2,2-[mercaptoethoxy(ethoxy)]ethanol and polyvinylpyrrolidone), and cationic (mercaptopentyl(trimethylammonium)). Each AuNP type appeared to adsorb Suwannee River Humic Acid (SRHA) as evidenced by measurable decreases in zeta potential in the presence of 5 mg C L(-1) SRHA. It was found that 5 mg C L(-1) SRHA provided a stabilizing effect at low ionic strength and in the presence of only monovalent ions while elevated concentrations of divalent cations lead to enhanced aggregation. The colloidal stability of the NPs in the absence of NOM is a function of capping agent, pH, ionic strength, and electrolyte valence. In the presence of NOM at the conditions examined in this study, the capping agent is a less important determinant of stability, and the adsorption of NOM is a controlling factor.
Collapse
Affiliation(s)
- Dylan P Stankus
- School of Chemical, Biological and Environmental Engineering, Oregon State University , 103 Gleeson Hall, Corvallis, Oregon 97331-2702, United States
| | | | | | | |
Collapse
|
38
|
Hung WL, Ho CT, Hwang LS. Inhibitory activity of natural occurring antioxidants on Thiyl radical-induced trans-arachidonic acid formation. J Agric Food Chem 2011; 59:1968-1973. [PMID: 21291247 DOI: 10.1021/jf1036307] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
trans-Fatty acids in humans not only may be obtained exogenously from food intake but also could be generated endogenously in tissues. The endogenous generation of trans-fatty acids, especially in the cell membranes induced by radical stress, is an inevitable source for the living species. Thiyl radicals generated from thiols act as the catalyst for the cis-trans isomerization of fatty acids. Arachidonic acid (5c,8c,11c,14c-20:4) with only two of the four double bonds deriving from linoleic acid in the diet can be used to differentiate the exogenous or endogenous formation of double bonds. The aim of this study is to evaluate the effective compounds in preventing thiyl radical-induced trans-arachidonic acid formation during UV irradiation in vitro. The trans-arachidonic acids were found to be 75% after 30 min UV irradiation of all-cis-arachidonic acid. Myricetin, luteolin, and quercetin had the highest thiyl radical scavenging activities, whereas sesamol, gallic acid, and vitamins A, C, and E had the lowest. The structures of flavonoids with higher thiyl radical scavenging activities were a 3',4'-o-dihydroxyl group in the B ring and a 2,3-double bond combined with a 4-keto group in the C ring. These effective compounds found in the present work may be used as lead compounds for the potential inhibitors in the formation of trans-fatty acids in vivo.
Collapse
Affiliation(s)
- Wei-Lun Hung
- Graduate Institute of Food Science and Technology, National Taiwan University, Taipei, Taiwan
| | | | | |
Collapse
|
39
|
Tukmechi A, Rahmati Andani HR, Manaffar R, Sheikhzadeh N. Dietary administration of beta-mercapto-ethanol treated Saccharomyces cerevisiae enhanced the growth, innate immune response and disease resistance of the rainbow trout, Oncorhynchus mykiss. Fish Shellfish Immunol 2011; 30:923-928. [PMID: 21296672 DOI: 10.1016/j.fsi.2011.01.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 12/29/2010] [Accepted: 01/21/2011] [Indexed: 05/30/2023]
Abstract
The effects of dietary whole cell yeast (Saccharomyces cerevisiae), n-3 HUFA-enriched yeast and treated yeast cells with beta-mercapto-ethanol (2ME) on immunity, growth performance and disease resistance to Yersinia ruckeri were investigated in Oncorhynchus mykiss. During 30 days, juvenile rainbow trout were fed diets supplemented with different forms of yeast at 5 × 10(7) CFU g(-1) or a control diet. After the feeding trial, remaining fish of each treatment were challenged by pathogenic Yersinia ruckeri and kept under observation for 14 days to record clinical signs and daily mortality rate. Yeast supplementation in all treatment groups significantly promoted the growth performance compared to control group. A significantly increase was also observed in immune responses in juvenile fish fed 2ME-treated yeast diet. More ever, the lowest fish mortality was obtained in this treatment group. The present results show that a diet supplemented with 2ME-treated yeast stimulates the immune system and growth of juvenile rainbow trout thus enhancing their resistance against Y. ruckeri.
Collapse
Affiliation(s)
- Amir Tukmechi
- Department of Pathobiology and Quality Control, Artemia and Aquatic Animals Research Institute, Urmia University, Iran.
| | | | | | | |
Collapse
|
40
|
Hu Y, Li J, Ma L, Peng Q, Feng W, Zhang L, He S, Yang F, Huang J, Li L. High efficiency transport of quantum dots into plant roots with the aid of silwet L-77. Plant Physiol Biochem 2010; 48:703-709. [PMID: 20451401 DOI: 10.1016/j.plaphy.2010.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 03/30/2010] [Accepted: 04/01/2010] [Indexed: 05/29/2023]
Abstract
Quantum dots (QDs) are a novel type of small, photostable and bright fluorophores that have been successfully applied to mammalian and human live cell imaging. In this study, highly dispersive water-soluble mercaptoacetic acid (MAA)-coated CdSe/ZnS QDs were synthesized, which were suitable for investigation as fluorescent probe labels. The treatment of maize seedling roots with QDs showed that the surfactant silwet L-77 aided the efficient transport of QDs into maize roots. Under a concentration ranging from 0.128 to 1.28 microM, QDs caused very low cytotoxicity on maize seed germination and root growth. The addition of mercuric chloride to the Hoagland solution resulted in a decrease of QD content in root tissues, and this decrease was reversed upon the addition of beta-mercaptoethanol, which suggests that mercury-sensitive processes play a significant role in regulating QD flow in the maize root system. We speculate that the apoplastic pathway can contribute substantially to the total quantity of QDs reaching the stele. Therefore, based on this transport approach, MAA-coated QDs can be utilized for live imaging in plant systems to verify known physiological processes.
Collapse
Affiliation(s)
- Yong Hu
- Key Laboratory of MOE for Plant Development Biology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Crans DC, Zhang B, Gaidamauskas E, Keramidas AD, Willsky GR, Roberts CR. Is vanadate reduced by thiols under biological conditions? Changing the redox potential of V(V)/V(IV) by complexation in aqueous solution. Inorg Chem 2010; 49:4245-56. [PMID: 20359175 PMCID: PMC2884226 DOI: 10.1021/ic100080k] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although dogma states that vanadate is readily reduced by glutathione, cysteine, and other thiols, there are several examples documenting that vanadium(V)-sulfur complexes can form and be observed. This conundrum has impacted life scientists for more than two decades. Investigation of this problem requires an understanding of both the complexes that form from vanadium(IV) and (V) and a representative thiol in aqueous solution. The reactions of vanadate and hydrated vanadyl cation with 2-mercaptoethanol have been investigated using multinuclear NMR, electron paramagnetic resonance (EPR), and UV-vis spectroscopy. Vanadate forms a stable complex of 2:2 stoichiometry with 2-mercaptoethanol at neutral and alkaline pH. In contrast, vanadate can oxidize 2-mercaptoethanol; this process is favored at low pH and high solute concentrations. The complex that forms between aqueous vanadium(IV) and 2-mercaptoethanol has a 1:2 stoichiometry and can be observed at high pH and high 2-mercaptoethanol concentration. The solution structures have been deduced based on coordination induced chemical shifts and speciation diagrams prepared. This work demonstrates that both vanadium(IV) and (V)-thiol complexes form and that redox chemistry also takes place. Whether reduction of vanadate takes place is governed by a combination of parameters: pH, solute- and vanadate-concentrations and the presence of other complexing ligands. On the basis of these results it is now possible to understand the distribution of vanadium in oxidation states (IV) and (V) in the presence of glutathione, cysteine, and other thiols and begin to evaluate the forms of the vanadium compounds that exert a particular biological effect including the insulin-enhancing agents, antiamoebic agents, and interactions with vanadium binding proteins.
Collapse
Affiliation(s)
- Debbie C Crans
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA.
| | | | | | | | | | | |
Collapse
|
42
|
Su YS, Lin YP, Cheng FC, Jen JF. In-capillary derivatization and stacking electrophoretic analysis of gamma-aminobutyric acid and alanine in tea samples to redeem the detection after dilution to decrease matrix interference. J Agric Food Chem 2010; 58:120-126. [PMID: 20000401 DOI: 10.1021/jf902958u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
An in-capillary derivatization and stacking capillary electrophoresis (CE) technique has been applied to redeem the detection of dilute analytes in the analysis of gamma-aminobutyric acid (GABA) and alanine (Ala) in tea samples. Extracts from samples were diluted to eliminate matrix interference before introduction into the CE system. GABA and Ala in the diluted sample zone were derivatized with o-phthaldialdehyde/2-mercaptoethanol (OPA/2-ME) to form fluorescence-labeled products in the stacking process, and the labeled derivatives were then enriched by online stacking. Optimal conditions for the stacking, such as the concentration of the background buffer solution, the matrix of the sample zone (sample solution), and the volume of the sample injection, were investigated and then applied to real sample analysis. Under optimum conditions, the detections were linear in the range of 5.0 nM-2.5 microM with the square of correlation coefficients (R2) of 0.9995 and 0.9992 for GABA and Ala, respectively. Detection limits were found to be 0.7 and 0.8 nM for GABA and Ala, respectively. Tea samples were analyzed with recoveries between 92.33 and 97.87% and between 94.36 and 96.46% for GABA and Ala, respectively. This method is a rapid, convenient, and sensitive process for determining GABA and Ala in complicated matrix samples such as tea samples.
Collapse
Affiliation(s)
- Yi-Song Su
- Department of Chemistry, National Chung-Hsing University, and Department of Education and Research, Taichung Veterans General Hospital, Taichung 402, Taiwan
| | | | | | | |
Collapse
|
43
|
McAlpin CR, Cox CR, Matyi SA, Voorhees KJ. Enhanced matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis of bacteriophage major capsid proteins with beta-mercaptoethanol pretreatment. Rapid Commun Mass Spectrom 2010; 24:11-14. [PMID: 19967739 DOI: 10.1002/rcm.4349] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bacteriophage (phage) proteins have been analyzed previously with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). However, analysis of phage major capsid proteins (MCPs) has been limited by the ability to reproducibly generate ions from MCP monomers. While the acidic conditions of MALDI-TOF MS sample preparation have been shown to aid in disassembly of some phage capsids, many require further treatment to successfully liberate MCP monomers. The findings presented here suggest that beta-mercaptoethanol reduction of the disulfide bonds linking phage MCPs prior to mass spectrometric analysis results in significantly increased MALDI-TOF MS sensitivity and reproducibility of Yersinia pestis-specific phage protein profiles.
Collapse
Affiliation(s)
- Casey R McAlpin
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA
| | | | | | | |
Collapse
|
44
|
Ye Q, Yan M, Yao Z, Xu L, Cao H, Li Z, Chen Y, Li S, Bai J, Xiong J, Ying H, Ouyang P. A new member of the short-chain dehydrogenases/reductases superfamily: purification, characterization and substrate specificity of a recombinant carbonyl reductase from Pichia stipitis. Bioresour Technol 2009; 100:6022-6027. [PMID: 19574038 DOI: 10.1016/j.biortech.2009.06.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 06/02/2009] [Accepted: 06/04/2009] [Indexed: 05/28/2023]
Abstract
A novel short-chain dehydrogenases/reductases superfamily (SDRs) reductase (PsCR) from Pichia stipitis that produced ethyl (S)-4-chloro-3-hydroxybutanoate with greater than 99% enantiomeric excess, was purified to homogeneity using fractional ammonium sulfate precipitation followed by DEAE-Sepharose chromatography. The enzyme purified from recombinant Escherichia coli had a molecular mass of about 35 kDa on SDS-PAGE and only required NADPH as an electron donor. The K(m) value of PsCR for ethyl 4-chloro-3-oxobutanoate was 4.9 mg/mL and the corresponding V(max) was 337 micromol/mg protein/min. The catalytic efficiency value was the highest ever reported for reductases from yeasts. Moreover, PsCR exhibited a medium-range substrate spectrum toward various keto and aldehyde compounds, i.e., ethyl-3-oxobutanoate with a chlorine substitution at the 2 or 4-position, or alpha,beta-diketones. In addition, the activity of the enzyme was strongly inhibited by SDS and beta-mercaptoethanol, but not by ethylene diamine tetra acetic acid.
Collapse
Affiliation(s)
- Qi Ye
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 210009, PR China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Abstract
The hydrogen bonding properties of a representative molecule, 2-mercaptoethanol (ME), of which two functional groups OH and SH are believed to interact competitively or selectively with proton-accepting molecules, have been studied. Three binary systems, namely ME-CCl(4), ME-dimethyl sulfoxide (DMSO), and ME-acetone, were investigated with excess infrared absorption spectroscopy. It is found that when DMSO or acetone is added into ME, they preferentially form hydrogen bonds with OH, and the hydrogen bonds in the ME-DMSO system are stronger than those in the ME-acetone system. When CCl(4) is added into ME, the weak hydrogen bonds involving the SH group are broken preferentially with increasing CCl(4) concentration. The dissociation process of ME in the inert diluent CCl(4) over the entire concentration range has been discussed in detail. In the very low concentration range of CCl(4), the highly hydrogen bonded ME multimers mainly break into medium-sized aggregates. The amount of the trimers and dimers first increases and then, at x(CCl(4)) = 0.77, begins to decrease. These results suggest that excess infrared spectroscopy can provide detailed molecular pictures in liquid solutions containing complex hydrogen bonding interactions. It can also help to locate individual peak positions in the deconvolution of overlapped absorption bands.
Collapse
Affiliation(s)
- Nan-Nan Wang
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, PR China
| | | | | |
Collapse
|
46
|
Abstract
Nucleobase radicals are the major family of reactive intermediates formed when nucleic acids are exposed to hydroxyl radical, which is produced by gamma-radiolysis and Fe.EDTA. Significant advances have been made in understanding the role of nucleobase radicals in oxidative DNA damage by independently generating these species from photochemical precursors. However, this approach has been used much less frequently to study RNA molecules. Norrish type I photocleavage of the tert-butyl ketone (2b) enabled studying the reactivity of 5'-benzoyl-5,6-dihydrouridin-6-yl (1b). High mass balances were observed under aerobic or anaerobic conditions, and O(2) did not affect the photochemical conversion of the ketone (2b) to 1b. Competition studies with O(2) indicate that the radical abstracts hydrogen atoms from beta-mercaptoethanol with a bimolecular rate constant = 2.6 +/- 0.5 x 10(6) M(-1)s(-1). The major product formed in the presence of O(2) was 5'-benzoyl-6-hydroxy-5,6-dihydrouridine (6). In contrast, 5-benzoyl-ribonolactone (7), a hypothetical product resulting from C1'-hydrogen atom abstraction by the peroxyl radical, could not be detected. Overall, tert-butyl ketone 2b is a clean source of 5'-benzoyl-5,6-dihydrouridin-6-yl (1b) and should prove useful for studying the reactivity of the respective radical in RNA.
Collapse
Affiliation(s)
- Cory A. Newman
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218
| | - Marino J. E. Resendiz
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218
| | - Jonathan T. Sczepanski
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218
| | - Marc M. Greenberg
- Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218
| |
Collapse
|
47
|
Schopfer FJ, Batthyany C, Baker PRS, Bonacci G, Cole MP, Rudolph V, Groeger AL, Rudolph TK, Nadtochiy S, Brookes PS, Freeman BA. Detection and quantification of protein adduction by electrophilic fatty acids: mitochondrial generation of fatty acid nitroalkene derivatives. Free Radic Biol Med 2009; 46:1250-9. [PMID: 19353781 PMCID: PMC3144282 DOI: 10.1016/j.freeradbiomed.2008.12.025] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nitroalkene fatty acid derivatives manifest a strong electrophilic nature, are clinically detectable, and induce multiple transcriptionally regulated anti-inflammatory responses. At present, the characterization and quantification of endogenous electrophilic lipids are compromised by their Michael addition with protein and small-molecule nucleophilic targets. Herein, we report a trans-nitroalkylation reaction of nitro-fatty acids with beta-mercaptoethanol (BME) and apply this reaction to the unbiased identification and quantification of reaction with nucleophilic targets. Trans-nitroalkylation yields are maximal at pH 7 to 8 and occur with physiological concentrations of target nucleophiles. This reaction is also amenable to sensitive mass spectrometry-based quantification of electrophilic fatty acid-protein adducts upon electrophoretic resolution of proteins. In-gel trans-nitroalkylation reactions also permit the identification of protein targets without the bias and lack of sensitivity of current proteomic approaches. Using this approach, it was observed that fatty acid nitroalkenes are rapidly metabolized in vivo by a nitroalkene reductase activity and mitochondrial beta-oxidation, yielding a variety of electrophilic and nonelectrophilic products that could be structurally characterized upon BME-based trans-nitroalkylation reaction. This strategy was applied to the detection and quantification of fatty acid nitration in mitochondria in response to oxidative inflammatory conditions induced by myocardial ischemia-reoxygenation.
Collapse
Affiliation(s)
- F J Schopfer
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Bazukian IL, Vardanian AE, Ambartsumian AA, Tozalakian PV, Popov IG. [Catalytic properties of Rhodotorula aurantiaca KM-1 phenylalanine ammonia-lyase]. Prikl Biokhim Mikrobiol 2009; 45:23-27. [PMID: 19235504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
L-Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) of the Rhodotorula aurantiaca strain KM-1 deaminates L-phenylalanine according to the Michaelis-Menten kinetics with K(M) = 1.75 +/- 0.44 mM and V(max) = 3.01 +/- 0.43 units/mg. The enzyme is competitively inhibited by D-phenylalanine with K(in) = 3.38 +/- 0.32 mM. The Michaelis-Menten kinetics was analyzed, the inhibition type (competitive, noncompetitive, and mixed) was identified, and corresponding kinetic parameters were calculated using the computer programs written in Gauss 4.0. PAL was most stable at pH 6.55 and lacked approximately 50% of its activity after incubation at 57 degrees C for 15 min. The yield of L-phenylalanine increased in the presence of mercaptoethanol, sodium ethylenediaminetetraacetate (EDTA), and ascorbic acid. The effects of EDTA and ascorbic acid were additive.
Collapse
|
49
|
Sun DX, Tian HF, Meng ZY, Du A, Yuan D, Gu RL, Wu ZN, Dou GF. Quantitative determination of acetylshikonin in macaque monkey blood by LC-ESI-MS/MS after precolumn derivatization with 2-mercaptoethanol and its application in pharmacokinetic study. Acta Pharmacol Sin 2008; 29:1499-506. [PMID: 19026170 DOI: 10.1111/j.1745-7254.2008.00898.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
AIM To develop and validate a novel precolumn derivatization method for the quantitative determination and pharmacokinetic application of acetylshikonin in macaque monkeys by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). METHODS 2-Mercaptoethanol was added to the blood sample as the derivatization reagent. The derivatization reaction formed 1 major derivation product, which was well correlated with acetylshikonin. The acetylshikonin concentrations in the biological samples were calculated by quantitative determination of the major derivation product using LC-ESI- MS/MS. Separation was achieved using a C18 column (2 mm x 50 mm, 5 microm) at room temperature and a linear gradient elution with a mobile phase containing methanol (1.96% acetic acid) and 10% methanol in water (1.96% acetic acid and 10 mmol/L ammonium acetate) at a flow rate of 0.2 mL/min. In addition, the major derivative, named derivative III, was identified by UV spectra, MS, and the (1)H-NMR and (13)C-NMR spectra. RESULTS Good linearity was obtained within the range of 5 and 2000 ng/mL (r>0.99 using a linear regression model with 1/x2 weighting) for acetylshikonin. The interday and intraday precisions were found to be less than 12.3%, with the exception of the lowest concentration, which was less than 17.2%. The interday and intraday accuracies, which were between -3% and 0.6%, were also observed. After the administration of acetylshikonin (80 mg/kg, po) in macaque monkeys, the pharmacokinetic parameters were obtained through the non-compartmental analysis, where the area under the concentration-time curve to the last measurable concentration, the terminal elimination halflife, and the mean residual time were 615.4+/-206.5 ng x dh/mL,12.3+/-1.6 h, and 10.2+/-0.7 h, respectively. CONCLUSION The method was validated and applied to the quantitative determination and pharmacokinetic study of acetylshikonin in the blood samples of macaque monkeys.
Collapse
Affiliation(s)
- Dong-xiao Sun
- Laboratory of Drug Metabolism and Pharmacokinetics, Beijing Institute of Transfusion Medicine, Beijing 100850, China
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Yu R, Yi T, Zhang L, Hong A, Dai Y, Zhou T. Intein-mediated rapid purification of recombinant maxadilan and M65 and their acute effects on plasma glucose. Acta Biochim Biophys Sin (Shanghai) 2008; 40:1015-22. [PMID: 19089299 DOI: 10.1111/j.1745-7270.2008.00485.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Maxadilan is a potent vasodilatory peptide present in the salivary glands of the sand fly. Maxadilan and M65, a deletion variation of maxadilan, are agonist- and antagonist-specific for the PAC1 receptor. In order to obtain the recombinant maxadilan and M65 efficiently by intein-mediated single column purification, the genes encoding maxadilan and M65 were designed, synthesized and cloned into Escherichia coli expression vector pKYB. The recombinant maxadilan and M65 with homogeneity over 95% were released from the chitin-bound intein tag by beta-mercaptoethanol. Intraperitoneal injection of the recombinant maxadilan caused an acute elevation of plasma glucose, imitating pituitary adenylate cyclase-activating polypeptide (PACAP) 27, in NIH mice, while the VPAC1-agonist and VPAC2-agonist had no significant effects on the levels of plasma glucose. M65 alone had no effect on the plasma glucose, but blocked the glucose excursion caused by maxadilan by 12.7% and blocked the glucose excursion caused by the PACAP 27 by 11.6%. The acute effects of the recombinant maxadilan and M65 on the plasma glucose indicated that they had the characteristics as the agonist and antagonist for PAC1.
Collapse
Affiliation(s)
- Rongjie Yu
- Bio-engineering Institute of Jinan University, Jinan University, Guangzhou, China.
| | | | | | | | | | | |
Collapse
|