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Weiser JR, Yueh A, Putnam D. Protein release from dihydroxyacetone-based poly(carbonate ester) matrices. Acta Biomater 2013; 9:8245-53. [PMID: 23747318 DOI: 10.1016/j.actbio.2013.05.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 05/11/2013] [Accepted: 05/22/2013] [Indexed: 11/19/2022]
Abstract
The release of therapeutics from solid polymer matrices is an important field of study in the area of controlled release. Here we report on the hydrolytic degradation of directly compressed discs comprised of statistically random polycarbonate esters based on lactic acid and dihydroxyacetone. The controlled release of two model proteins, bovine serum albumin and lysozyme, was explored using two percentage loadings (5 and 10 wt.%). A first order release pattern and a trend for faster protein release with increasing dihydroxyacetone content were observed over a time period ranging from 2.5 to 70 days. To analyze the effects of the internal polymer matrix environment on protein stability the enzymatic activity of released lysozyme was monitored. The results show a high level of enzyme activity for the polycarbonate ester ratios with more dihydroxyacetone in the backbone and at least 50% activity over the first month of release from the co-polymer ratios with more lactic acid in the backbone. Modeling of the release kinetics using the Korsmeyer-Peppas model showed a high correlation, indicating that the release of protein is a complex mechanism controlled by protein diffusion through, and erosion of, the co-polymer matrix. The outcomes show that these polycarbonate esters may be useful materials for extended controlled release of proteins.
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Affiliation(s)
- Jennifer R Weiser
- Department of Biomedical Engineering, Cornell University, 526 Campus Road, Ithaca, NY 14853, USA
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Maiser B, Dismer F, Hubbuch J. Optimization of random PEGylation reactions by means of high throughput screening. Biotechnol Bioeng 2013; 111:104-14. [PMID: 23939788 DOI: 10.1002/bit.25000] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 06/09/2013] [Accepted: 07/08/2013] [Indexed: 01/10/2023]
Abstract
Since the first FDA approval of a PEGylated product in 1990, so called random PEGylation reactions are still used to increase the efficacy of biopharmaceuticals and represent the major technology of all approved PEG-modified drugs. However, the great influence of process parameters on PEGylation degree and the PEG-binding site results in a lack of reaction specificity which can have severe impact on the product profile. Consequently, reproducible and well characterized processes are essential to meet increasing regulative requirements resulting from the quality-by-design (QbD) initiative, especially for this kind of modification type. In this study we present a general approach which combines the simple chemistry of random PEGylation reactions with high throughput experimentation (HTE) to achieve a well-defined process. Robotic based batch experiments have been established in a 96-well plate format and were analyzed to investigate the influence of different PEGylation conditions for lysozyme as model protein. With common SEC analytics highly reproducible reaction kinetics were measured and a significant influence of PEG-excess, buffer pH, and reaction time could be investigated. Additional mono-PEG-lysozyme analytics showed the impact of varying buffer pH on the isoform distribution, which allowed us to identify optimal process parameters to get a maximum concentration of each isoform. Employing Micrococcus lysodeikticus based activity assays, PEG-lysozyme33 was identified to be the isoform with the highest residual activity, followed by PEG-lysozyme1 . Based on these results, a control space for a PEGylation reaction was defined with respect to an optimal overall volumetric activity of mono-PEG-lysozyme isoform mixtures.
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Affiliation(s)
- Benjamin Maiser
- Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Science, Karlsruhe Institute of Technology (KIT), 76131, Karlsruhe, Germany
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53
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Gélinas M, Fortier M, Lajeunesse A, Fournier M, Gagnon C, Gagné F. Energy status and immune system alterations in Elliptio complanata after ingestion of cyanobacteria Anabaena flos-aquae. ECOTOXICOLOGY (LONDON, ENGLAND) 2013; 22:457-468. [PMID: 23354932 DOI: 10.1007/s10646-012-1039-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/23/2012] [Indexed: 06/01/2023]
Abstract
Cyanobacteria have often been described as nutritionally poor for herbivorous organisms. To gain additional information on the potential impacts of invertebrates feeding on cyanobacteria, we fed Elliptio complanata mussels with two types of algae: Anabaena flos-aquae (cyanobacteria) and Pseudokirchneriella subcapitata (green algae). Physiological parameters were examined at the energy status, immune system and oxidative stress levels. Energy status was examined by following the rate of electron transport activity in mitochondria (a measure of cellular energy expense) and lipid/sugar stores in the visceral mass. The cyanobacteria were not actively producing toxins. Based on the digestive gland index, the mussels fed equally on either regime. However, the energy status in mussels fed A. flos-aquae revealed that the total sugar was lower in the digestive gland, whereas mitochondrial electron transport activity (MET), once corrected against the digestive gland somatic index, showed increased energy expenses. Acetylcholinesterase activity and lipid peroxidation (LPO) were also higher in mussels fed with A. flos-aquae compared with mussels fed with P. subcapitata. LPO was correlated by mitochondrial activity in both the digestive gland and gills, suggesting that oxidative stress resulted from metabolic respiration. Immunocompetence (phagocytic activity, natural killer cell-like activity, haemocyte count and viability) and humoral level of lysozyme were not affected in mussels by the algae or cyanobacteria regime. Moreover, the xenobiotic conjugating enzyme, glutathione S-transferase, hemoprotein oxidase and vitellogenin-like proteins were not affected in mussel organs via ingestion of A. flos-aquae. Our study suggests that ingestion of cyanobacteria leads to increased energy expenses, oxidative stress and increased acetylcholine turnover in mussels.
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Affiliation(s)
- Malorie Gélinas
- Emerging Methods Section, Environment Canada, Montreal, QC, Canada.
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54
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Lamppa JW, Tanyos SA, Griswold KE. Engineering Escherichia coli for soluble expression and single step purification of active human lysozyme. J Biotechnol 2012; 164:1-8. [PMID: 23220215 DOI: 10.1016/j.jbiotec.2012.11.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/07/2012] [Accepted: 11/15/2012] [Indexed: 10/27/2022]
Abstract
Genetically engineered variants of human lysozyme represent promising leads in the battle against drug-resistant bacterial pathogens, but early stage development and testing of novel lysozyme variants is constrained by the lack of a robust, scalable and facile expression system. While wild type human lysozyme is reportedly produced at 50–80 kg per hectare of land in recombinant rice, this plant-based system is not readily scaled down to bench top production, and it is therefore not suitable for development and characterization of novel lysozyme variants. Here, we describe a novel and efficient expression system capable of producing folded, soluble and functional human lysozyme in Escherichia coli cells. To achieve this goal, we simultaneously co-express multiple protein folding chaperones as well as harness the lysozyme inhibitory protein, Ivy. Our strategy exploits E. coli's ease of culture, short doubling time, and facile genetics to yield upwards of 30 mg/l of soluble lysozyme in a bioreactor system, a 3000-fold improvement over prior efforts in E. coli. Additionally, molecular interactions between lysozyme and a his-tagged Ivy allows for one-step purification by IMAC, yielding as much as 21 mg/l of purified enzyme. We anticipate that our expression and purification platform will facilitate further development of engineered lysozymes having utility in disease treatment and other practical applications.
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Affiliation(s)
- John W Lamppa
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA
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55
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Ahn M, De Genst E, Kaminski Schierle GS, Erdelyi M, Kaminski CF, Dobson CM, Kumita JR. Analysis of the native structure, stability and aggregation of biotinylated human lysozyme. PLoS One 2012; 7:e50192. [PMID: 23166837 PMCID: PMC3500338 DOI: 10.1371/journal.pone.0050192] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 10/22/2012] [Indexed: 11/29/2022] Open
Abstract
Fibril formation by mutational variants of human lysozyme is associated with a fatal form of hereditary non-neuropathic systemic amyloidosis. Defining the mechanistic details of lysozyme aggregation is of crucial importance for understanding the origin and progression of this disease and related misfolding conditions. In this study, we show that a biotin moiety can be introduced site-specifically at Lys33 of human lysozyme. We demonstrate, using biophysical techniques, that the structure and stability of the native-state of the protein are not detectably altered by this modification, and that the ability to form amyloid fibrils is unchanged. By taking advantage of biotin-avidin interactions, we show that super-resolution fluorescence microscopy can generate detailed images of the mature fibrils. This methodology can readily enable the introduction of additional probes into the protein, thereby providing the means through which to understand, in detail, the nature of the aggregation process of lysozyme and its variants under a variety of conditions.
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Affiliation(s)
- Minkoo Ahn
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Erwin De Genst
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Miklos Erdelyi
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
- National Physics Laboratory, Teddington, United Kingdom
| | - Clemens F. Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | | | - Janet R. Kumita
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
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56
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Gust M, Gélinas M, Fortier M, Fournier M, Gagné F. In vitro immunotoxicity of environmentally representative antibiotics to the freshwater mussel Elliptio complanata. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2012; 169:50-58. [PMID: 22683480 DOI: 10.1016/j.envpol.2012.05.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/02/2012] [Accepted: 05/13/2012] [Indexed: 06/01/2023]
Abstract
The separate and combined in vitro toxic effects of antibiotics (ciprofloxacin, erythromycin, novobiocin, oxytetracycline, sulfamethazole and trimethoprim) commonly found in urban wastewater effluents were assessed on the immune parameters of Elliptio complanata at environmentally relevant concentrations. The observed responses were then compared to those produced by the physicochemical-treated wastewater effluent of a major city before and after the removal of microorganisms. Most of the selected antibiotics, separately and as mixture, induced changes in immune responses. The removal of microorganisms and fine particles from the effluent increased or decreased the resulting immunotoxic effects, depending of the observed parameter. The immunotoxic effects of erythromycin, sulfamethoxazole and trimethoprim were closely associated to the antibiotic mixture and the filtered effluent. In conclusion, the data revealed that the removal of fine particles and microorganisms from municipal effluents can alter the toxic nature of the effluent that is closely associated with the cumulative effects of antibiotics.
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Affiliation(s)
- M Gust
- Fluvial Ecosystem Research, Environment Canada, Montreal, Quebec, Canada.
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57
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Farcy E, Gagné F, Martel L, Fortier M, Trépanier S, Brousseau P, Fournier M. Short-term physiological effects of a xenobiotic mixture on the freshwater mussel Elliptio complanata exposed to municipal effluents. ENVIRONMENTAL RESEARCH 2011; 111:1096-1106. [PMID: 21831370 DOI: 10.1016/j.envres.2011.07.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 07/20/2011] [Accepted: 07/22/2011] [Indexed: 05/31/2023]
Abstract
The aim of this study was to investigate the short-term effects of tertiary-treated municipal effluents on the freshwater mussel Elliptio complanata. Caged mussels were immersed during 2 weeks in a river located North of Montreal Island, upstream/downstream the outfall and in one reference site located at the beginning of the Rivière des Prairies. A selection of biomarkers was analyzed to depict changes on various physiological systems: general physiology (mussel viability, condition index and gonado-somatic index), immune status (hemocyte viability, cellularity, phagocytosis efficiency, NK-like cytotoxic activity and lysozyme activity), inflammation (cyclo-oxygenase activity), detoxification (glutathione-S-transferases activity) and vitellogenesis (alkali-labile phosphate level). The analysis of total and fecal coliform counts in water and of heterotrophic bacteria levels in mussel tissues showed that the bacteriological quality of the water strongly decreased from the reference site to the downstream site. This was correlated with a significant loss of weight and an increase of mussel mortality. Cellularity and phagocytosis efficiency were significantly increased in the downstream site compared to the reference site. Though not statistically significant, lysozyme activity was also increased. NK-like cytotoxicity, activity of the pro-inflammatory enzyme COX and the levels of ALP and MT were not significantly changed. Conversely, the municipal effluents induced a significant increase of GST activity in downstream site, indicating a stimulation of detoxification metabolism. Altogether, these results confirm that a short-term exposure to a mixture of bacterial and chemical compounds released by the wastewater treatment plant La Pinière induces adverse physiological effects in E. complanata, as observed with the modulation of immune response and induction of detoxification metabolism.
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Affiliation(s)
- E Farcy
- Environment Canada, Fluvial Ecosystem Research, 105 McGill Avenue, Montreal, Quebec, Canada H2Y 2E7.
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58
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Kumita JR, Helmfors L, Williams J, Luheshi LM, Menzer L, Dumoulin M, Lomas DA, Crowther DC, Dobson CM, Brorsson AC. Disease-related amyloidogenic variants of human lysozyme trigger the unfolded protein response and disturb eye development in Drosophila melanogaster. FASEB J 2011; 26:192-202. [PMID: 21965601 PMCID: PMC3250245 DOI: 10.1096/fj.11-185983] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We have created a Drosophila model of lysozyme amyloidosis to investigate the in vivo behavior of disease-associated variants. To achieve this objective, wild-type (WT) protein and the amyloidogenic variants F57I and D67H were expressed in Drosophila melanogaster using the UAS-gal4 system and both the ubiquitous and retinal expression drivers Act5C-gal4 and gmr-gal4. The nontransgenic w(1118) Drosophila line was used as a control throughout. We utilized ELISA experiments to probe lysozyme protein levels, scanning electron microscopy for eye phenotype classification, and immunohistochemistry to detect the unfolded protein response (UPR) activation. We observed that expressing the destabilized F57I and D67H lysozymes triggers UPR activation, resulting in degradation of these variants, whereas the WT lysozyme is secreted into the fly hemolymph. Indeed, the level of WT was up to 17 times more abundant than the variant proteins. In addition, the F57I variant gave rise to a significant disruption of the eye development, and this correlated to pronounced UPR activation. These results support the concept that the onset of familial amyloid disease is linked to an inability of the UPR to degrade completely the amyloidogenic lysozymes prior to secretion, resulting in secretion of these destabilized variants, thereby leading to deposition and associated organ damage.
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Affiliation(s)
- Janet R Kumita
- Department of Chemistry, University of Cambridge, Cambridge, UK
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59
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Zhang Y, Wang Z, Zhang J, Chen C, Wu Q, Zhang L, Zhang X. Quantitative determination of chitinolytic activity of lysozyme using half-deacetylated chitosan as a substrate. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2011.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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60
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Tsai PJ, Chen YS, Sheu CH, Chen CY. Effect of nanogrinding on the pigment and bioactivity of Djulis ( Chenopodium formosanum Koidz.). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:1814-1820. [PMID: 21306107 DOI: 10.1021/jf1041273] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Betanin is an antioxidant pigment found in djulis, a grain native to Taiwan, and is a natural source food coloring, but the bright red color degrades rapidly if submitted to light, heat, or oxygen. The effects of nanogrinding on the stability of pigments and bioactive components are unknown. In this study, the color characteristics and bioactivity (antioxidant capacity and enzyme activity) of nanoparticle (NP) djulis was compared with those of intact granules (IG) and microparticles (MP). Results showed that the NP samples exhibited the highest betanin content (2.04 mg/g), which was almost twice that of IG. It was observed that nanogrinding resulted in higher pigment extraction efficiency. However, during storage (5-35 °C for 56 days), NP samples showed the most serious pigment degradation, and this color degradation, as expected, had the lowest activation energy. This was more evident when the storage temperature was high. Antioxidant capacities showed the same trends. MP and NP exhibited significantly higher activity of superoxide dismutaste-like activity, lactoperoxidase (LPO), and lysozyme than IG. Gel permeation chromatography confirmed the degradation of larger particles during nanogrinding, which might favor enzyme extraction and their activities. Statistical analysis revealed a close relationship between betanin and antioxidant capacity.
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Affiliation(s)
- Pi-Jen Tsai
- Department of Food Science, National Pingtung University of Technology and Science , 1 Hsueh Fu Road, Nei-Pu Hsiang, 91207 Pingtung, Taiwan, Republic of China
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61
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Lasanta C, Roldán A, Caro I, Pérez L, Palacios V. Use of lysozyme for the prevention and treatment of heterolactic fermentation in the biological aging of sherry wines. Food Control 2010. [DOI: 10.1016/j.foodcont.2010.03.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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62
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Scanlon TC, Teneback CC, Gill A, Bement JL, Weiner JA, Lamppa JW, Leclair LW, Griswold KE. Enhanced antimicrobial activity of engineered human lysozyme. ACS Chem Biol 2010; 5:809-18. [PMID: 20604527 DOI: 10.1021/cb1001119] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lysozymes contain a disproportionately large fraction of cationic residues, and are thereby attracted toward the negatively charged surface of bacterial targets. Importantly, this conserved biophysical property may inhibit lysozyme antibacterial function during acute and chronic infections. A mouse model of acute pulmonary Pseudomonas aeruginosa infection demonstrated that anionic biopolymers accumulate to high concentrations in the infected lung, and the presence of these species correlates with decreased endogenous lysozyme activity. To develop antibacterial enzymes designed specifically to be used as antimicrobial agents in the infected airway, the electrostatic potential of human lysozyme (hLYS) was remodeled by protein engineering. A novel, high-throughput screen was implemented to functionally interrogate combinatorial libraries of charge-engineered hLYS proteins, and variants with improved bactericidal activity were isolated and characterized in detail. These studies illustrate a general mechanism by which polyanions inhibit lysozyme function, and they are the first direct demonstration that decreasing hLYS's net cationic character improves its antibacterial activity in the presence of disease-associated biopolymers. In addition to avoiding electrostatic sequestration, at least one charge-engineered variant also kills bacteria more rapidly in the absence of inhibitory biopolymers; this observation supports a novel hypothesis that tuning the cellular affinity of peptidoglycan hydrolases may be a general strategy for improving kinetics of bacterial killing.
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Affiliation(s)
| | - Charlotte C. Teneback
- The Vermont Lung Center, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405
| | | | - Jenna L. Bement
- The Vermont Lung Center, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405
| | | | | | - Laurie W. Leclair
- The Vermont Lung Center, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05405
| | - Karl E. Griswold
- Thayer School of Engineering
- Program in Molecular and Cellular Biology
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755
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63
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Xu Z, Liu XW, Ma YS, Gao HW. Interaction of nano-TiO2 with lysozyme: insights into the enzyme toxicity of nanosized particles. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2010; 17:798-806. [PMID: 19390888 DOI: 10.1007/s11356-009-0153-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Accepted: 04/01/2009] [Indexed: 05/27/2023]
Abstract
BACKGROUND, AIM, AND SCOPE Nanomaterials have been used increasingly in industrial production and daily life, but their human exposure may cause health risks. The interactions of nanomaterial with functional biomolecules are often applied as a precondition for its cytotoxicity and organ toxicity where various proteins have been investigated in the past years. In the present study, nano-TiO(2) was selected as the representative of nanomaterials and lysozyme as a representative for enzymes. By investigating their interaction by various instrumentations, the objective is to identify the action sites and types, estimate the effect on the enzyme structure and activity, and reveal the toxicity mechanism of nanomaterial. MATERIALS AND METHODS Laboratory-scale experiments were carried out to investigate the interactions of nano-TiO(2) with lysozyme. The interaction of nano-TiO(2) particles with lysozyme has been studied in the analogous physiological media in detail by UV spectrometry, fluorophotometry, circular dichroism (CD), scanning electron microscope, zeta-potential, and laser particle size. RESULTS The interaction accorded with the Langmuir isothermal adsorption and the saturation number of lysozyme is determined to be 580 per nano-TiO(2) particle (60 nm of size) with 4.7 x 10(6) M(-1) of the stability constant in the physiological media. The acidity and ion strength of the media obviously affected the binding of lysozyme. The warping and deformation of the lysozyme bridging were demonstrated by the conversion of its spatial structure from alpha-helix into a beta-sheet, measured by CD. In the presence of nano-TiO(2), the bacteriolysis activity of lysozyme was subjected to an obvious inhibition. DISCUSSION The two-step binding model of lysozyme was proposed, in which lysozyme was adsorbed on nano-TiO(2) particle surface by electrostatic interaction and then the hydrogen bond (N-H...O and O-H...O) formed between nano-TiO(2) particle and polar side groups of lysozyme. The adsorption of lysozyme obeyed the Langmuir isothermal model. The binding of lysozyme is dependent on the acidity and ion strength of the media. The bigger TiO(2) aggregate was formed in the presence of lysozyme where lysozyme may bridge between nano-TiO(2) particles. The coexistence of nano-TiO(2) particles resulted in the transition of lysozyme conformation from an alpha-helix into a beta-sheet and a substantial inactivation of lysozyme. The beta-sheet can induce the formation of amyloid fibrils, a process which plays a major role in pathology. CONCLUSIONS Lysozyme was adsorbed on the nano-TiO(2) particle surface via electrostatic attraction and hydrogen bonds, and they also bridged among global nano-TiO(2) particles to form the colloidal particles. As a reasonable deduction of this study, nano-TiO(2) might have some toxic impacts on biomolecules. Our data suggest that careful attention be paid to the interaction of protein and nanomaterials. This could contribute to nanomaterial toxicity assessment. RECOMMENDATIONS AND PERSPECTIVES Our results strongly suggest that nano-TiO(2) has an obvious impact on biomolecules. Our data suggest that more attention should be paid to the potential toxicity of nano-TiO(2) on biomolecules. Further research into the toxicity of nanosized particles needs to be carried out prior to their cell toxicity and tissue toxicity. These investigations might serve as the basis for determining the toxicity and application of nanomaterials.
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Affiliation(s)
- Zhen Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
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64
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Bouchard B, Gagné F, Fortier M, Fournier M. An in-situ study of the impacts of urban wastewater on the immune and reproductive systems of the freshwater mussel Elliptio complanata. Comp Biochem Physiol C Toxicol Pharmacol 2009; 150:132-40. [PMID: 19362165 DOI: 10.1016/j.cbpc.2009.04.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 04/02/2009] [Accepted: 04/02/2009] [Indexed: 11/27/2022]
Abstract
The goal of this study was to examine the disruptive effects of municipal effluents on the immune and reproductive systems of freshwater mussels. For 30 days, caged mussels were immersed in the Rivière des Mille Iles (Quebec, Canada), 150 m both upstream and downstream from two urban wastewater treatment plants: station F (Fabreville) and station A (Auteuil), which serve the city of Laval. Station F is 12 km upstream from station A. The immune and reproductive statuses of the mussels were thereafter determined. Though the weight/shell length ratio was not affected, the effluent induced mortality up to 60% at downstream sites. Total hemocyte counts increased, and phagocytosis and lysozyme activities were induced at station F, whereas these responses were suppressed at station A. Heterotrophic bacteria levels in mussels were negatively correlated with phagocytosis, showing the importance of this process in defending against infection. Inflammation biomarkers such as nitric oxide and cyclooxygenase activity were the same for all sites but were positively correlated with phagocytosis activity. The production of vitellogenin (Vtg)-like proteins was significantly induced at the site downstream from station A and was strongly associated with phagocytosis. This was further supported through analysis of covariance, of Vtg responses against phagocytosis, revealing that Vtg was no longer induced at the sites upstream and downstream from station A. The data support the contention that Vtg was involved, in part at least, in the immune system in mussels. Both Vtg and immune status are impacted by urban effluents and should be considered when using the Vtg biomarker to search for the presence of (xeno)estrogens in contaminated environments.
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Affiliation(s)
- B Bouchard
- Environment Canada, Fluvial Ecosystem Research, 105 McGill, 7th Floor, Montréal, Quebec, Canada
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65
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Chen FF, Tang YN, Wang SL, Gao HW. Binding of brilliant red compound to lysozyme: insights into the enzyme toxicity of water-soluble aromatic chemicals. Amino Acids 2008; 36:399-407. [DOI: 10.1007/s00726-008-0069-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2008] [Accepted: 03/18/2008] [Indexed: 10/22/2022]
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66
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Jiang ZL, Huang GX. Resonance scattering spectra of micrococcus lysodeikticus and its application to assay of lysozyme activity. Clin Chim Acta 2007; 376:136-41. [PMID: 16979609 DOI: 10.1016/j.cca.2006.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/02/2006] [Accepted: 08/02/2006] [Indexed: 11/23/2022]
Abstract
BACKGROUND Several methods, including turbidimetric and colorimetric methods, have been reported for the detection of lysozyme activity. However, there is no report about the resonance scattering spectral (RSS) assay, which is based on the catalytic effect of lysozyme on the hydrolysis of micrococcus lysodeikticus (ML) and its resonance scattering effect. METHODS RESULTS ML has 5 resonance scattering peaks at 360 400, 420, 470, and 520 nm with the strongest one at 470 nm. The concentration of ML in the range of 2.0x10(6)-9.3x10(8) cells/ml is proportional to the RS intensity at 470 nm (I(470 nm)). A new catalytic RSS method has been proposed for 0.24-40.0 U/ml (or 0.012-2.0 mug/ml) lysozyme activity, with a detection limit (3sigma) of 0.014 U/ml (or 0.0007 microg/ml). Saliva samples were assayed by this method, and it is in agreement with the results of turbidimetric method. The slope, intercept and the correlation coefficient of the regression analysis of the 2 assays were 0.9665, -87.50, and 0.9973, respectively. CONCLUSION The assay has high sensitivity and simplicity.
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Affiliation(s)
- Zhi-Liang Jiang
- Department of Material Science and Chemical Engineering, Guilin University of Technology, Guilin 541004, China.
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Li J, He XW, Wu YL, Li WY, Zhang YK. Determination of Lysozyme at the Nanogram Level by a Resonance Light-Scattering Technique with Functionalized CdTe Nanoparticles. ANAL SCI 2007; 23:331-5. [PMID: 17372378 DOI: 10.2116/analsci.23.331] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Nanoparticles of cadmium telluride coated with mercaptoacetic acid were prepared in the water phase. Further, an assay of lysozyme with a sensitivity at the nanogram level is proposed. At pH 7.28, lysozyme with positive charges can interact with CdTe nanoparticles. The resonance light-scattering (RLS) signals of functionalized nano-CdTe were greatly enhanced by lysozyme in the region of 300-600 nm, characterized with peaks located at 367, 470 and 533 nm. A linear relationship could be established between the enhanced RLS intensity and the lysozyme concentration in the range of 0.06-4.0 microg mL-1. The limit of detection was 9.5 ng mL-1. The contents of lysozyme were determined with recoveries of 95.6-104.8% and RSD of 1.5-2.3%, respectively. This method is sensitive, rapid, accurate and simple, and provides a new and reliable means for the quantity determination of lysozyme.
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Affiliation(s)
- Juan Li
- Department of Chemistry, Nankai University, Tianjin, China
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Kumita JR, Johnson RJK, Alcocer MJC, Dumoulin M, Holmqvist F, McCammon MG, Robinson CV, Archer DB, Dobson CM. Impact of the native-state stability of human lysozyme variants on protein secretion by Pichia pastoris. FEBS J 2006; 273:711-20. [PMID: 16441658 DOI: 10.1111/j.1742-4658.2005.05099.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We report the secreted expression by Pichia pastoris of two human lysozyme variants F57I and W64R, associated with systemic amyloid disease, and describe their characterization by biophysical methods. Both variants have a substantially decreased thermostability compared with wild-type human lysozyme, a finding that suggests an explanation for their increased propensity to form fibrillar aggregates and generate disease. The secreted yields of the F57I and W64R variants from P. pastoris are 200- and 30-fold lower, respectively, than that of wild-type human lysozyme. More comprehensive analysis of the secretion levels of 10 lysozyme variants shows that the low yields of these secreted proteins, under controlled conditions, can be directly correlated with a reduction in the thermostability of their native states. Analysis of mRNA levels in this selection of variants suggests that the lower levels of secretion are due to post-transcriptional processes, and that the reduction in secreted protein is a result of degradation of partially folded or misfolded protein via the yeast quality control system. Importantly, our results show that the human disease-associated mutations do not have levels of expression that are out of line with destabilizing mutations at other sites. These findings indicate that a complex interplay between reduced native-state stability, lower secretion levels, and protein aggregation propensity influences the types of mutation that give rise to familial forms of amyloid disease.
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Johnson RJK, Christodoulou J, Dumoulin M, Caddy GL, Alcocer MJC, Murtagh GJ, Kumita JR, Larsson G, Robinson CV, Archer DB, Luisi B, Dobson CM. Rationalising Lysozyme Amyloidosis: Insights from the Structure and Solution Dynamics of T70N Lysozyme. J Mol Biol 2005; 352:823-36. [PMID: 16126226 DOI: 10.1016/j.jmb.2005.07.040] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 07/06/2005] [Accepted: 07/12/2005] [Indexed: 11/23/2022]
Abstract
T70N human lysozyme is the only known naturally occurring destabilised lysozyme variant that has not been detected in amyloid deposits in human patients. Its study and a comparison of its properties with those of the amyloidogenic variants of lysozyme is therefore important for understanding the determinants of amyloid disease. We report here the X-ray crystal structure and the solution dynamics of T70N lysozyme, as monitored by hydrogen/deuterium exchange and NMR relaxation experiments. The X-ray crystal structure shows that a substantial structural rearrangement results from the amino acid substitution, involving residues 45-51 and 68-75 in particular, and gives rise to a concomitant separation of these two loops of up to 6.5A. A marked decrease in the magnitudes of the generalised order parameter (S2) values of the amide nitrogen atom, for residues 70-74, shows that the T70N substitution increases the flexibility of the peptide backbone around the site of mutation. Hydrogen/deuterium exchange protection factors measured by NMR spectroscopy were calculated for the T70N variant and the wild-type protein. The protection factors for many of backbone amide groups in the beta-domain of the T70N variant are decreased relative to those in the wild-type protein, whereas those in the alpha-domain display wild-type-like values. In pulse-labelled hydrogen/deuterium exchange experiments monitored by mass spectrometry, transient but locally cooperative unfolding of the beta-domain of the T70N variant and the wild-type protein was observed, but at higher temperatures than for the amyloidogenic variants I56T and D67H. These findings reveal that such partial unfolding is an intrinsic property of the human lysozyme structure, and suggest that the readiness with which it occurs is a critical feature determining whether or not amyloid deposition occurs in vivo.
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Affiliation(s)
- Russell J K Johnson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
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71
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Karlsson H, Leanderson P, Tagesson C, Lindahl M. Lipoproteomics I: mapping of proteins in low-density lipoprotein using two-dimensional gel electrophoresis and mass spectrometry. Proteomics 2005; 5:551-65. [PMID: 15627967 DOI: 10.1002/pmic.200300938] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The molecular mechanisms underlying the relationship between low-density lipoprotein (LDL) and the risk of atherosclerosis are not clear. Therefore, detailed information about the protein composition of LDL may contribute to reveal its role in atherogenesis and the mechanisms that lead to coronary disease in humans. Here, we sought to map the proteins in human LDL by a proteomic approach. LDL was isolated by two-step discontinuous density-gradient ultracentrifugation and the proteins were separated with two-dimensional gel electrophoresis and identified with peptide mass fingerprinting, using matrix assisted laser desorption/ionization-time of flight-mass spectrometry and with amino acid sequencing using electrospray ionization tandem mass spectrometry. These procedures identified apo B-100, apo C-II, apo C-III (three isoforms), apo E (four isoforms), apo A-I (two isoforms), apo A-IV, apo J and apo M (three isoforms not previously described). In addition, three proteins that have not previously been identified in LDL were found: serum amyloid A-IV (two isoforms), calgranulin A, and lysozyme C. The identities of apo M, calgranulin A, and lysozyme C were confirmed by sequence information obtained after collision-induced dissociation fragmentation of peptides characteristic for these proteins. Moreover, the presence of lysozyme C was further corroborated by demonstrating enriched hydrolytic activity in LDL against Micrococcus lysodeikticus. These results indicate that in addition to the dominating apo B-100, LDL contains a number of other apolipoproteins, many of which occur in different isoforms. The demonstration, for the first time, that LDL contains calgranulin A and lysozyme C raises the possibility that LDL proteins may play hitherto unknown role(s) in immune and inflammatory reactions of the arterial wall.
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MESH Headings
- Apolipoprotein A-I/analysis
- Apolipoprotein B-100
- Apolipoprotein C-III
- Apolipoproteins/analysis
- Apolipoproteins A/analysis
- Apolipoproteins B/analysis
- Apolipoproteins C/analysis
- Apolipoproteins E/analysis
- Apolipoproteins M
- Calgranulin A/analysis
- Centrifugation, Density Gradient
- Chromatography, Gel
- Clusterin
- Electrophoresis, Gel, Two-Dimensional
- Glycoproteins/analysis
- Humans
- Lipocalins
- Lipoproteins, LDL/analysis
- Lipoproteins, LDL/isolation & purification
- Mass Spectrometry
- Molecular Chaperones/analysis
- Peptide Mapping
- Protein Isoforms/analysis
- Proteome/analysis
- Proteomics
- Sequence Analysis, Protein
- Spectrometry, Mass, Electrospray Ionization
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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Affiliation(s)
- Helen Karlsson
- Division of Occupational and Environmental Medicine, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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