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Wang J, Tang S, Zhang K. Quantitation of polyethylene glycol by size exclusion chromatography with charged aerosol, differential refractive index, and multi-angle light scattering detectors. J Pharm Biomed Anal 2024; 238:115854. [PMID: 38016231 DOI: 10.1016/j.jpba.2023.115854] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/29/2023] [Accepted: 11/05/2023] [Indexed: 11/30/2023]
Abstract
Polyethylene glycol (PEG) has found tremendous applications in pharmaceutical products and has played a critical role in PEGylated drug modalities to improve pharmacokinetic properties and biological efficacy. The characterization and quantitation of PEGs are essential to control manufacture process and drug product quality. However, the assay value of PEG could change dramatically depending on the structures of the PEG and the detection techniques used. In this study, we developed a size exclusion chromatographic (SEC) method for quantitative PEG analysis, and we systematically evaluated the performance of three online detectors with different operating principles: a charged aerosol detector (CAD), a differential refractive index (dRI) detector, and a multi-angle light scattering detector (MALS). Fourteen PEG compounds covering a wide range of molecular weight (MW, 1 - 40 kDa) and molecular architectures (linear, branched, Y-shaped and multi-arm geometries) were evaluated by these three detection techniques. Our study revealed that the dRI showed the most universal responses among all the PEGs regardless of their molecular weight or geometries. In the contrast, CAD and MALS detector showed MW-dependent and semi-universal geometry-dependent responses. Another key finding is that the relative response factor for each multi-arm PEG in the CAD and the MALS were inversely correlated, suggesting both can be applied to qualitatively assess polymers of different architectures, including the ones with subtle differences in their core structures. The comparison of the three detectors not only provides the fundamental and comprehensive understanding of PEG quantitation but also enables the process development and control of high-quality PEGs in producing PEGylated therapeutics in the pharmaceutical industry.
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Affiliation(s)
- Jenny Wang
- Synthetic Molecule Analytical Chemistry, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, United States
| | - Shijia Tang
- Synthetic Molecule Analytical Chemistry, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, United States
| | - Kelly Zhang
- Synthetic Molecule Analytical Chemistry, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, United States.
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2
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Tsutsumi K, Ueta E, Kato H, Matsumoto K, Horiguchi S, Okada H. Optimization of Isolation Method for Extracellular Vesicles from Pancreatic Juice and Impact of Protease Activity. Dig Dis Sci 2022; 67:4797-4804. [PMID: 35037137 DOI: 10.1007/s10620-021-07339-x] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/19/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUNDS Pancreatic juice (PJ) is directly associated with pancreatic lesions, including pancreatic ductal cancer and intraductal papillary mucinous neoplasm-derived cancer. Therefore, EVs secreted from these lesions into PJ can be promising biomarkers for early diagnosis. However, there are limited data from analysis of EVs in PJ samples. AIMS AND METHODS We aimed to determine the stability of EVs in PJ collected using endoscopic naso-pancreatic drainage (ENPD) tubes as well as catheter during endoscopic retrograde cholangiography (ERCP), with or without the impact of positive protease activity, and optimize the EV isolation method. RESULTS Size exclusion chromatography was found to be an optimal isolation method for EVs in PJ as it achieved higher recovery and purity of EVs compared with differential ultracentrifugation and polymer-based precipitation. Approximately 40% of the PJ samples collected during ERCP and more than 90% of those collected using ENPD tubes had positive protease activity. In vitro exposure to room temperature for less than 3 h was harmless to the structure of double-membrane EVs in PJ and the expression levels of TSG101, even with positive protease activity. CONCLUSIONS We clarified the physiobiological status of EVs in PJ and optimized the EV isolation method using suitable PJ samples; these findings can be utilized to discover biomarkers for cancer diagnosis and elucidate their function.
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Affiliation(s)
- Koichiro Tsutsumi
- Department of Gastroenterology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama-city, Okayama, 700-8558, Japan.
| | - Eijiro Ueta
- Department of Gastroenterology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama-city, Okayama, 700-8558, Japan.,Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
| | - Hironari Kato
- Department of Gastroenterology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama-city, Okayama, 700-8558, Japan
| | - Kazuyuki Matsumoto
- Department of Gastroenterology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama-city, Okayama, 700-8558, Japan
| | - Shigeru Horiguchi
- Department of Gastroenterology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama-city, Okayama, 700-8558, Japan
| | - Hiroyuki Okada
- Department of Gastroenterology, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama-city, Okayama, 700-8558, Japan.,Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
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3
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Burgess-Brown NA, Mahajan P, Strain-Damerell C, Fernandez-Cid A, Gileadi O, Gräslund S. Screening and Production of Recombinant Human Proteins: Protein Production in E. coli. Methods Mol Biol 2021; 2199:45-66. [PMID: 33125644 DOI: 10.1007/978-1-0716-0892-0_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
In Chapter 3 , we described the Structural Genomics Consortium (SGC) process for generating multiple constructs of truncated versions of each protein using LIC. In this chapter we provide a step-by-step procedure of our E. coli system for test expressing intracellular (soluble) proteins in a 96-well format that enables us to identify which proteins or truncated versions are expressed in a soluble and stable form suitable for structural studies. In addition, we detail the process for scaling up cultures for large-scale protein purification. This level of production is required to obtain sufficient quantities (i.e., milligram amounts) of protein for further characterization and/or structural studies (e.g., crystallization or cryo-EM experiments). Our standard process is purification by immobilized metal affinity chromatography (IMAC) using nickel resin followed by size exclusion chromatography (SEC), with additional procedures arising from the complexity of the protein itself.
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Yang Y, Wang Y, Wei S, Zhou C, Yu J, Wang G, Wang W, Zhao L. Extracellular vesicles isolated by size-exclusion chromatography present suitability for RNomics analysis in plasma. J Transl Med 2021; 19:104. [PMID: 33712033 PMCID: PMC7953782 DOI: 10.1186/s12967-021-02775-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/04/2021] [Indexed: 12/12/2022] Open
Abstract
Background Extracellular vesicles (EVs), known as cell-derived membranous structures harboring a variety of biomolecules, have been widely used in liquid biopsy. Due to the complex biological composition of plasma, plasma RNA omics analysis (RNomics) is easily affected, thus it is necessary to select an optimal strategy from exiting methods according to the performance for intended application. Methods In this study, four different strategies for EVs isolation were performed and compared (i.e. ultracentrifugation (UC), size exclusion chromatography (SEC), and two most frequently-used commercially available isolation kit (ExoQuick and exoEasy). We compared the yield, purity, PCR quantification of RNAs, miRNA-seq analyses and mRNA-seq analyses of RNAs from EVs isolated using four methods. Results The results showed that the lowest miRNA binding protein AGO2 (Argonaute-2) and the highest EVs-specific miRNA and lncRNA were observed in EVs obtained through SEC, meanwhile the content of the non-specific miRNA was the lowest. Further RNA-Seq data revealed that RNAs obtained via SEC presented more useful reads for both miRNA and mRNA. Furthermore, the mRNA delivered via SEC tended to have a concentration comparable to the ideal FPKM (Fragments Per Kilobase Million) value. Conclusions SEC shall be used as an optimal strategy for the isolation of EVs in plasma RNomics analysis. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-021-02775-9.
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Affiliation(s)
- Yang Yang
- Department of General Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, Hebei, China
| | - Yaojie Wang
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, Hebei, China
| | - Sisi Wei
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, Hebei, China
| | - Chaoxi Zhou
- Department of General Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, Hebei, China
| | - Jiarui Yu
- Department of Radiation Oncology, North China University of Science and Technology Affiliated People's Hospital, Tangshan, 063000, Hebei, China
| | - Guiying Wang
- Department of General Surgery, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, Hebei, China
| | - Wenxi Wang
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, Hebei, China.
| | - Lianmei Zhao
- Research Center, The Fourth Hospital of Hebei Medical University, Shijiazhuang, 050011, Hebei, China.
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5
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Falcicchio P, Levisson M, Kengen SWM, Koutsopoulos S, van der Oost J. (Hyper)Thermophilic Enzymes: Production and Purification. Methods Mol Biol 2021; 2178:469-78. [PMID: 33128766 DOI: 10.1007/978-1-0716-0775-6_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The discovery of thermophilic and hyperthermophilic microorganisms, thriving at environmental temperatures near or above 100 °C, has revolutionized our ideas about the upper temperature limit at which life can exist. The characterization of (hyper)thermostable proteins has broadened our understanding and presented new opportunities for solving one of the most challenging problems in biophysics: how are structural stability and biological function maintained at high temperatures where "normal" proteins undergo dramatic structural changes? In our laboratory, we have purified and studied many thermostable and hyperthermostable proteins in an attempt to determine the molecular basis of heat stability. Here, we present methods to express such proteins and enzymes in E. coli and provide a general protocol for overproduction and purification. The ability to produce enzymes that retain their stability and activity at elevated temperatures creates exciting opportunities for a wide range of biocatalytic applications.
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6
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Ly QV, Nghiem LD, Cho J, Maqbool T, Hur J. Organic carbon source-dependent properties of soluble microbial products in sequencing batch reactors and its effects on membrane fouling. J Environ Manage 2019; 244:40-47. [PMID: 31108309 DOI: 10.1016/j.jenvman.2019.05.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 01/30/2019] [Revised: 05/07/2019] [Accepted: 05/10/2019] [Indexed: 06/09/2023]
Abstract
This study investigated the influence of three different organic carbon sources including sodium acetate (SOD), glucose (GLU), and starch (STAR), on soluble microbial products (SMP), which presumably have dissimilar uptake rates and metabolic pathways, in sequencing batch reactors (SBR) and their subsequent effects on membrane fouling of ultrafiltration (UF). SMP were mainly characterized by fluorescence excitation emission matrix coupled with parallel factor analysis (EEM-PARAFAC) and size exclusion chromatography (SEC). SMP produced in SOD-fed SBR showed higher abundances of protein-like fluorescent component and large sized aliphatic biopolymer (BP) than GLU- or STAR-fed counterpart did, while the STAR-based operation resulted in more SMP enriched with humic-like fluorescence. The differences in SMP exerted marked effects on UF membrane fouling as indicated by the highest fouling potential with reversibility shown for the SMP from the SOD-fed reactor. Regardless of the carbon source, BP fraction and protein-like component exhibited the greatest extent of reversible fouling, suggesting that size exclusion plays a critical role. However, notable differences in the reversible fouling propensity of relatively smaller size fractions among the three SBRs signified the possible involvement of chemical interactions as a secondary fouling mechanism and its dependency on different carbon sources. Our results provide a new insight into the roles of carbon sources in the characteristics of SMP in biological treatment systems and their effects on the post-treatment using membrane filtration, which is ultimately beneficial to the optimization of biological treatment design and membrane filtration operation.
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Affiliation(s)
- Quang Viet Ly
- Department of Environment & Energy, Sejong University, Seoul, 05006, South Korea; State Key Laboratory of Separation Membranes and Membrane Processes/National Center for International Joint Research on Membrane Science and Technology, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin, 300387, PR China
| | - Long D Nghiem
- Centre for Technology in Water and Wastewater, University of Technology Sydney, Ultimo NSW, 2007, Australia
| | - Jinwoo Cho
- Department of Environment & Energy, Sejong University, Seoul, 05006, South Korea
| | - Tahir Maqbool
- Department of Environment & Energy, Sejong University, Seoul, 05006, South Korea
| | - Jin Hur
- Department of Environment & Energy, Sejong University, Seoul, 05006, South Korea.
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7
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Lee YK, Lee MH, Hur J. A new molecular weight (MW) descriptor of dissolved organic matter to represent the MW-dependent distribution of aromatic condensation: Insights from biodegradation and pyrene binding experiments. Sci Total Environ 2019; 660:169-176. [PMID: 30640085 DOI: 10.1016/j.scitotenv.2019.01.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 12/05/2018] [Revised: 12/31/2018] [Accepted: 01/05/2019] [Indexed: 06/09/2023]
Abstract
In this study, we utilized a size exclusion chromatography (SEC) system that was equipped with a fluorescence emission scanning mode to explore the heterogeneous distribution of the humification index (HIX) values within bulk dissolved organic matter (DOM). The HIX-based SEC chromatograms showed that the molecular weight (MW)-dependent distribution of aromatic condensation was heavily affected by the DOM sources and the progress of biodegradation. The HIX heterogeneity across different MW was more pronounced for terrestrial versus aquatic DOM sources. Microbial incubation of leaf litter DOM led to the initial enhancement of the HIX at a relatively low MW, followed by a gradual increase at larger MW values. The dynamic changes of the HIX can be attributed to (1) the preferential removal of non-aromatic or less-aromatic molecules by microorganisms, (2) the production of microbial metabolites, (3) microbial humification, and (4) self-assemblage of humic-like molecules. From the SEC chromatograms, the HIX-based average molecular weight (or MWHIX) was proposed as a unifying surrogate to represent an MW that was highly associated with aromatic condensation. The MWHIX discriminated four different DOM sources and described well the biodegradation-induced changes. The MWHIX also presented a good positive correlation with pyrene organic carbon-normalized binding coefficients (Koc). The prediction capability of the MWHIX for pyrene Koc was higher than those based on the single descriptors of bulk DOM, such as HIX and MW, which revealed its superior linkage with the DOM reactivity related to both MW and HIX.
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Affiliation(s)
- Yun Kyung Lee
- Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, South Korea
| | - Mi-Hee Lee
- Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, South Korea
| | - Jin Hur
- Department of Environment and Energy, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, South Korea.
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8
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Ly QV, Nghiem LD, Sibag M, Maqbool T, Hur J. Effects of COD/N ratio on soluble microbial products in effluent from sequencing batch reactors and subsequent membrane fouling. Water Res 2018; 134:13-21. [PMID: 29407647 DOI: 10.1016/j.watres.2018.01.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [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: 10/26/2017] [Revised: 12/29/2017] [Accepted: 01/10/2018] [Indexed: 06/07/2023]
Abstract
The relative ratios of chemical oxygen demand (COD) to nitrogen (N) in wastewater are known to have profound effects on the characteristics of soluble microbial products (SMP) from activated sludge. In this study, the changes in the SMP characteristics upon different COD/N ratios and the subsequent effects on ultrafiltration (UF) membrane fouling potentials were examined in sequencing batch reactors (SBR) using excitation emission matrix-parallel factor analysis (EEM-PARAFAC) and size exclusion chromatography (SEC). Three unique fluorescent components were identified from the SMP samples in the bioreactors operated at the COD/N ratios of 100/10 (N rich), 100/5 (N medium), and 100/2 (N deficient). The tryptophan-like component (C1) was the most depleted at the N medium condition. Fulvic-like (C2) and humic-like (C3) components were more abundant with N rich wastewater. Greater abundances of large size biopolymer (BP) and low molecular weight neutrals (LMWN) were found under the N deficient and N rich conditions, respectively. SMPs from various COD/N exhibited a greater degree on membrane fouling following the order of 100/2 > 100/10 > 100/5. C1 and C2 had close associations with reversible and irreversible fouling, respectively, while the reversible fouling potential of C3 depended on the COD/N ratios. No significant impact of COD/N ratio was observed on the relative contributions of SMP size fractions to either reversible or irreversible fouling potential. However, the COD/N ratios likely altered the BP foulants' composition with greater contribution of proteinaceous substances to reversible fouling under the N deficient condition than at other N richer conditions. The opposite trend was observed for irreversible fouling. Our results provided further insight into changes in different SMP constitutes and their membrane fouling in response to microbial activities under different COD/N ratios.
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Affiliation(s)
- Quang Viet Ly
- Department of Environment & Energy, Sejong University, Seoul 05006, South Korea
| | - Long D Nghiem
- Centre for Technology in Water and Wastewater, University of Technology Sydney, NSW 2007, Australia
| | - Mark Sibag
- Department of Environment & Energy, Sejong University, Seoul 05006, South Korea
| | - Tahir Maqbool
- Department of Environment & Energy, Sejong University, Seoul 05006, South Korea
| | - Jin Hur
- Department of Environment & Energy, Sejong University, Seoul 05006, South Korea.
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9
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Taube R, Ganzert L, Grossart HP, Gleixner G, Premke K. Organic matter quality structures benthic fatty acid patterns and the abundance of fungi and bacteria in temperate lakes. Sci Total Environ 2018; 610-611:469-481. [PMID: 28818662 DOI: 10.1016/j.scitotenv.2017.07.256] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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: 04/18/2017] [Revised: 07/27/2017] [Accepted: 07/29/2017] [Indexed: 05/25/2023]
Abstract
Benthic microbial communities (BMCs) play important roles in the carbon cycle of lakes, and benthic littoral zones in particular have been previously highlighted as biogeochemical hotspots. Dissolved organic matter (DOM) presents the major carbon pool in lakes, and although the effect of DOM composition on the pelagic microbial community composition is widely accepted, little is known about its effect on BMCs, particularly aquatic fungi. Therefore, we investigated the composition of benthic littoral microbial communities in twenty highly diverse lakes in northeast Germany. DOM quality was analyzed via size exclusion chromatography (SEC), fluorescence parallel factor analyses (PRAFACs) and UV-Vis spectroscopy. We determined the BMC composition and biomass using phospholipid-derived fatty acids (PLFA) and extended the interpretation to the analysis of fungi by applying a Bayesian mixed model. We present evidence that the quality of DOM structures the BMCs, which are dominated by heterotrophic bacteria and show low fungal biomass. The fungal biomass increases when the DOM pool is processed by microorganisms of allochthonous origin, whereas the opposite is true for bacteria.
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Affiliation(s)
- Robert Taube
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Chemical Analytics and Biogeochemistry, 12587 Berlin, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Biogeochemistry, 15374 Müncheberg, Germany.
| | - Lars Ganzert
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Experimental Limnology, 16775 Stechlin, Germany
| | - Hans-Peter Grossart
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Experimental Limnology, 16775 Stechlin, Germany; Potsdam University, Institute for Biochemistry and Biology, 14469 Potsdam, Germany
| | - Gerd Gleixner
- Max Planck Institute for Biogeochemistry, Jena, Germany
| | - Katrin Premke
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Dept. Chemical Analytics and Biogeochemistry, 12587 Berlin, Germany; Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Biogeochemistry, 15374 Müncheberg, Germany
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10
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Lee YK, Hur J. Using two-dimensional correlation size exclusion chromatography (2D-CoSEC) to explore the size-dependent heterogeneity of humic substances for copper binding. Environ Pollut 2017; 227:490-497. [PMID: 28494401 DOI: 10.1016/j.envpol.2017.04.099] [Citation(s) in RCA: 4] [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: 03/06/2017] [Revised: 04/13/2017] [Accepted: 04/13/2017] [Indexed: 06/07/2023]
Abstract
Knowledge of the heterogeneous distribution of humic substances (HS) reactivities along a continuum of molecular weight (MW) is crucial for the systems where the HS MW is subject to change. In this study, two dimensional correlation spectroscopy combined with size exclusion chromatography (2D-CoSEC) was first utilized to obtain a continuous and heterogeneous presence of copper binding characteristics within bulk HS with respect to MW. HS solutions with varying copper concentrations were directly injected into a size exclusion chromatography (SEC) system with Tris-HCl buffer as a mobile phase. Several validation tests confirmed neither structural disruption of HS nor competition effect of the mobile phase used. Similar to batch systems, fluorescence quenching was observed in the chromatograms over a wide range of HS MW. 2D-CoSEC maps of a soil-derived HS (Elliot soil humic acid) showed the greater fluorescence quenching degrees with respect to the apparent MW on the order of 12500 Da > 10600 Da > 7000 Da > 15800 Da. The binding constants calculated based on modified Stern-Volmer equation were consistent with the 2D-CoSEC results. More heterogeneity of copper binding affinities within bulk HS was found for the soil-derived HS versus an aquatic HS. The traditional fluorescence quenching titration method using ultrafiltered HS size fractions failed to delineate detailed distribution of the copper binding characteristics, exhibiting a much shorter range of the binding constants than those obtained from the 2D-CoSEC. Our proposed technique demonstrated a great potential to describe metal binding characteristics of HS at high MW resolution, providing a clear picture of the size-dependent metal-HS interactions.
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Affiliation(s)
- Yun-Kyung Lee
- Department of Environment and Energy, Sejong University, Seoul 05006, South Korea
| | - Jin Hur
- Department of Environment and Energy, Sejong University, Seoul 05006, South Korea.
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11
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Wagner BM, Schuster SA, Boyes BE, Shields TJ, Miles WL, Haynes MJ, Moran RE, Kirkland JJ, Schure MR. Superficially porous particles with 1000Å pores for large biomolecule high performance liquid chromatography and polymer size exclusion chromatography. J Chromatogr A 2017; 1489:75-85. [PMID: 28213987 DOI: 10.1016/j.chroma.2017.01.082] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/20/2017] [Accepted: 01/29/2017] [Indexed: 10/20/2022]
Abstract
To facilitate mass transport and column efficiency, solutes must have free access to particle pores to facilitate interactions with the stationary phase. To ensure this feature, particles should be used for HPLC separations which have pores sufficiently large to accommodate the solute without restricted diffusion. This paper describes the design and properties of superficially porous (also called Fused-Core®, core shell or porous shell) particles with very large (1000Å) pores specifically developed for separating very large biomolecules and polymers. Separations of DNA fragments, monoclonal antibodies, large proteins and large polystyrene standards are used to illustrate the utility of these particles for efficient, high-resolution applications.
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Affiliation(s)
- Brian M Wagner
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA
| | - Stephanie A Schuster
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA.
| | - Barry E Boyes
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA
| | - Taylor J Shields
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA
| | - William L Miles
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA
| | - Mark J Haynes
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA
| | - Robert E Moran
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA
| | - Joseph J Kirkland
- Advanced Materials Technology, Inc., 3521 Silverside Rd., Ste. 1-K, Quillen Bldg, Wilmington, DE 19810, USA
| | - Mark R Schure
- Theoretical Separation Science Laboratory, Kroungold Analytical, Inc., 1299 Butler Pike, Blue Bell, PA 19422, USA
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12
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Maspolim Y, Zhou Y, Guo C, Xiao K, Ng WJ. The effect of pH on solubilization of organic matter and microbial community structures in sludge fermentation. Bioresour Technol 2015; 190:289-98. [PMID: 25965254 DOI: 10.1016/j.biortech.2015.04.087] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [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: 02/25/2015] [Revised: 04/20/2015] [Accepted: 04/24/2015] [Indexed: 05/24/2023]
Abstract
Sludge fermentation between pH 4 and 11 was investigated to generate volatile fatty acids (VFA). Despite the highest sludge solubilization of 25.9% at pH 11, VFA accumulation was optimized at pH 8 (12.5% out of 13.1% sludge solubilization). 454 pyrosequencing identified wide diversity of acidogens in bioreactors operated at the various pHs, with Tissierella, Petrimonas, Proteiniphilum, Levilinea, Proteiniborus and Sedimentibacter enriched and contributing to the enhanced fermentation at pH 8. Hydrolytic enzymatic assays determined abiotic effect to be the leading cause for improved solubilization under high alkaline condition but the environmental stress at pH 9 and above might lead to disrupt biological activities and eventually VFA production. Furthermore, molecular weight (MW) characterization of the soluble fractions found large MW aromatic substances at pH 9 and above, that is normally associated with poor biodegradability, making them disadvantageous for subsequent bioprocesses. The findings provided information to better understand and control sludge fermentation.
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Affiliation(s)
- Yogananda Maspolim
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Yan Zhou
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Chenghong Guo
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
| | - Keke Xiao
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Wun Jern Ng
- Advanced Environmental Biotechnology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
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