1
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Patil U, Kourentzi K, Willson RC. Competitive protein adsorption in isocratic anion exchange chromatography. J Chromatogr A 2024; 1730:465114. [PMID: 38964160 DOI: 10.1016/j.chroma.2024.465114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 06/01/2024] [Accepted: 06/22/2024] [Indexed: 07/06/2024]
Abstract
Protein chromatography is the dominant method of purification of biopharmaceuticals. Although all practical chromatography involves competitive absorption and separation of M. species, competitive protein absorption has remained inadequately understood. We previously introduced the measurement of equilibrium protein adsorption isotherms with all intensive variables held constant, including competitor concentration. In this work, we introduce isocratic chromatographic retention measurements of dynamic protein adsorption in the presence of a constant concentration of a competitor protein. These measurements are achieved by establishing a dynamic equilibrium with a constant concentration of competitor (insulin) in the mobile phase flowing through an ion exchange adsorbent column and following the behavior of a test protein (α-lactalbumin) injected into this environment. We observed decreased retention times for α-lactalbumin in presence of the competitor. The presence of competitor also reduces the heterogeneity of the sites available for adsorption of the test protein. This investigation provides an approach to fundamental understanding of competitive dynamics of multicomponent protein chromatography.
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Affiliation(s)
- Ujwal Patil
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Katerina Kourentzi
- William A. Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas, USA
| | - Richard C Willson
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA; William A. Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas, USA; Escuela de Medicina y Ciencias de la Salud TecSalud, Monterrey, Nuevo León, NM.
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2
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Zhou Y, Ramirez A, Yuill EM, Wang Q. Mechanistic studies to understand peak tailing due to sulfinic acid- and carboxylic acid-silanophilic interactions in reversed-phase liquid chromatography. J Chromatogr A 2024; 1721:464819. [PMID: 38537485 DOI: 10.1016/j.chroma.2024.464819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 04/13/2024]
Abstract
Silanophilic interactions are a primary contributor to peak tailing of acidic pharmaceutical compounds, thus a thorough understanding is especially important for reversed-phase liquid chromatography (RPLC) method development. Herein, a sulfinic acid compound that exhibited severe peak tailing in RPLC with acidic mobile phases was carefully studied. Results indicated that the neutral protonated form of the sulfinic acid is involved in the strong interaction that leads to peak tailing, but that tailing can be mitigated with a blocking effect achieved through use of acetic acid modifier in the mobile phase. Peak tailing was also observed with other structurally-similar sulfinic acids and carboxylic acids but was, in general, less severe with the latter. The Hydrophobic Subtraction Model (HSM) was applied to six commercial C18 columns that exhibited different tailing behaviors for the sulfinic acid compound in attempts to identify key sites of interaction within the stationary phase. A combination of heated acid column wash experiments and density functional theory (DFT) calculations indicate that the differential interactions of the acids with vicinal silanol pairs in the stationary phase play a major role in peak tailing.
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Affiliation(s)
- Yiyang Zhou
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA.
| | - Antonio Ramirez
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA
| | - Elizabeth M Yuill
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA
| | - Qinggang Wang
- Chemical Process Development, Bristol Myers Squibb Company, 1 Squibb Drive, New Brunswick, NJ 08903, USA
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3
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Scrosati PM, Konermann L. Atomistic Details of Peptide Reversed-Phase Liquid Chromatography from Molecular Dynamics Simulations. Anal Chem 2023; 95:3892-3900. [PMID: 36745777 DOI: 10.1021/acs.analchem.2c05667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Peptide separations by reversed-phase liquid chromatography (RPLC) are an integral part of bottom-up proteomics. These separations typically employ C18 columns with water/acetonitrile gradient elution in the presence of formic acid. Despite the widespread use of such workflows, the exact nature of peptide interactions with the stationary and mobile phases is poorly understood. Here, we employ microsecond molecular dynamics (MD) simulations to uncover details of peptide RPLC. We examined two tryptic peptides, a hydrophobic and a hydrophilic species, in a slit pore lined with C18 chains that were grafted onto SiO2 support. Our simulations explored peptide trapping, followed by desorption and elution. Trapping in an aqueous mobile phase was initiated by C18 contacts with Lys butyl moieties. This was followed by extensive anchoring of nonpolar side chains (Leu/Ile/Val) in the C18 layer. Exposure to water/acetonitrile triggered peptide desorption in a stepwise fashion; charged sites close to the termini were the first to lift off, followed by the other residues. During water/acetonitrile elution, both peptides preferentially resided close to the pore center. The hydrophilic peptide exhibited no contacts with the stationary phase under these conditions. In contrast, the hydrophobic species underwent multiple transient Leu/Ile/Val binding interactions with C18 chains. These nonpolar interactions represent the foundation of differential peptide retention, in agreement with the experimental elution behavior of the two peptides. Extensive peptide/formate ion pairing was observed in water/acetonitrile, particularly at N-terminal sites. Overall, this work uncovers an unprecedented level of RPLC molecular details, paving the way for MD simulations as a future tool for improving retention prediction algorithms and for the design of novel column materials.
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Affiliation(s)
- Pablo M Scrosati
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
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4
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Monge Neria R, Kisley L. Single-Molecule Imaging in Commercial Stationary Phase Particles Using Highly Inclined and Laminated Optical Sheet Microscopy. Anal Chem 2023; 95:2245-2252. [PMID: 36652205 DOI: 10.1021/acs.analchem.2c03753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We resolve the three-dimensional, nanoscale locations of single-molecule analytes within commercial stationary phase materials using highly inclined and laminated optical sheet (HILO) microscopy. Single-molecule fluorescence microscopy of chromatography can reveal the molecular heterogeneities that lead to peak broadening, but past work has focused on surfaces designed to mimic stationary phases, which have different physical and chemical properties than the three-dimensional materials used in real columns and membranes. To extend single-molecule measurements to commercial stationary phases, we immobilize individual stationary phase particles and modify our microscope for imaging at further depths with HILO, a method which was originally developed to resolve single molecules in cells of comparable size to column packing materials (∼5-10 μm). We describe and characterize how to change the angle of incidence to achieve HILO so that other researchers can easily incorporate this method onto their existing epi- or total internal reflection fluorescence microscopes. We show improvements up to a 32% in signal-to-background ratio and 118% in the number of single molecules detected within stationary phase particles when using HILO compared to epifluorescence. By controlling the objective position relative to the sample, we produce three-dimensional maps of molecule locations throughout entire stationary phase particles at nanoscale lateral and axial resolutions. The number of localized molecules remains constant axially throughout isolated stationary phase particles and between different particles, indicating that heterogeneity in a separation would not be caused by such affinity differences at microscales but instead kinetic differences at nanoscales on identifiable and distinct adsorption sites.
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Affiliation(s)
- Ricardo Monge Neria
- Department of Physics, Case Western Reserve University, Cleveland, Ohio44106-7079, United States
| | - Lydia Kisley
- Department of Physics, Case Western Reserve University, Cleveland, Ohio44106-7079, United States.,Department of Chemistry, Case Western Reserve University, Cleveland, Ohio44106-7079, United States
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5
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Drobota M, Ursache S, Aflori M. Surface Functionalities of Polymers for Biomaterial Applications. Polymers (Basel) 2022; 14:polym14122307. [PMID: 35745883 PMCID: PMC9229900 DOI: 10.3390/polym14122307] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/03/2022] [Accepted: 06/04/2022] [Indexed: 02/04/2023] Open
Abstract
Changes of a material biointerface allow for specialized cell signaling and diverse biological responses. Biomaterials incorporating immobilized bioactive ligands have been widely introduced and used for tissue engineering and regenerative medicine applications in order to develop biomaterials with improved functionality. Furthermore, a variety of physical and chemical techniques have been utilized to improve biomaterial functionality, particularly at the material interface. At the interface level, the interactions between materials and cells are described. The importance of surface features in cell function is then examined, with new strategies for surface modification being highlighted in detail.
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Affiliation(s)
- Mioara Drobota
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Aleea Gr. Ghica Voda, 700487 Iasi, Romania;
| | - Stefan Ursache
- Innovative Green Power, No. 5 Iancu Bacalu Street, 700029 Iasi, Romania;
| | - Magdalena Aflori
- “Petru Poni” Institute of Macromolecular Chemistry, 41A Aleea Gr. Ghica Voda, 700487 Iasi, Romania;
- Correspondence:
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6
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Misiura A, Shen H, Tauzin L, Dutta C, Bishop LDC, Carrejo NC, Zepeda O J, Ramezani S, Moringo NA, Marciel AB, Rossky PJ, Landes CF. Single-Molecule Dynamics Reflect IgG Conformational Changes Associated with Ion-Exchange Chromatography. Anal Chem 2021; 93:11200-11207. [PMID: 34346671 DOI: 10.1021/acs.analchem.1c01799] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Conformational changes of antibodies and other biologics can decrease the effectiveness of pharmaceutical separations. Hence, a detailed mechanistic picture of antibody-stationary phase interactions that occur during ion-exchange chromatography (IEX) can provide critical insights. This work examines antibody conformational changes and how they perturb antibody motion and affect ensemble elution profiles. We combine IEX, three-dimensional single-protein tracking, and circular dichroism spectroscopy to investigate conformational changes of a model antibody, immunoglobulin G (IgG), as it interacts with the stationary phase as a function of salt conditions. The results indicate that the absence of salt enhances electrostatic attraction between IgG and the stationary phase, promotes surface-induced unfolding, slows IgG motion, and decreases elution from the column. Our results reveal previously unreported details of antibody structural changes and their influence on macroscale elution profiles.
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Affiliation(s)
- Anastasiia Misiura
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Hao Shen
- Department of Chemistry and Biochemistry, Kent State University, 800 E Summit Street, Kent, Ohio 44240, United States
| | - Lawrence Tauzin
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Chayan Dutta
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Logan D C Bishop
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Nicole C Carrejo
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Jorge Zepeda O
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Shahryar Ramezani
- Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Nicholas A Moringo
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Amanda B Marciel
- Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Peter J Rossky
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Christy F Landes
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States.,Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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7
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Sánchez-Morán H, Weltz JS, Schwartz DK, Kaar JL. Understanding Design Rules for Optimizing the Interface between Immobilized Enzymes and Random Copolymer Brushes. ACS APPLIED MATERIALS & INTERFACES 2021; 13:26694-26703. [PMID: 34081428 DOI: 10.1021/acsami.1c02443] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A long-standing goal in the field of biotechnology is to develop and understand design rules for the stabilization of enzymes upon immobilization to materials. While immobilization has sometimes been successful as a strategy to stabilize enzymes, the design of synthetic materials that stabilize enzymes remains largely empirical. We sought to overcome this challenge by investigating the mechanistic basis for the stabilization of immobilized lipases on random copolymer brush surfaces comprised of poly(ethylene glycol) methacrylate (PEGMA) and sulfobetaine methacrylate (SBMA), which represent novel heterogeneous supports for immobilized enzymes. Using several related but structurally diverse lipases, including Bacillus subtilis lipase A (LipA), Rhizomucor miehei lipase, Candida rugosa lipase, and Candida antarctica lipase B (CALB), we showed that the stability of each lipase at elevated temperatures was strongly dependent on the fraction of PEGMA in the brush layer. This dependence was explained by developing and applying a new algorithm to quantify protein surface hydrophobicity, which involved using unsupervised cluster analysis to identify clusters of hydrophobic atoms. Characterization of the lipases showed that the optimal brush composition correlated with the free energy of solvation per enzyme surface area, which ranged from -17.1 kJ/mol·nm2 for LipA to -11.8 kJ/mol·nm2 for CALB. Additionally, using this algorithm, we found that hydrophobic patches consisting of aliphatic residues had a higher free energy than patches consisting of aromatic residues. By providing the basis for rationally tuning the interface between enzymes and materials, this understanding will transform the use of materials to reliably ruggedize enzymes under extreme conditions.
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Affiliation(s)
- Héctor Sánchez-Morán
- Department of Chemical and Biological Engineering, University of Colorado, Campus Box 596, Boulder, Colorado 80309, United States
| | - James S Weltz
- Department of Chemical and Biological Engineering, University of Colorado, Campus Box 596, Boulder, Colorado 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado, Campus Box 596, Boulder, Colorado 80309, United States
| | - Joel L Kaar
- Department of Chemical and Biological Engineering, University of Colorado, Campus Box 596, Boulder, Colorado 80309, United States
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8
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Bishop LDC, Misiura A, Landes CF. A new metric for relating macroscopic chromatograms to microscopic surface dynamics: the distribution function ratio (DFR). Analyst 2021; 146:4268-4279. [PMID: 34105529 DOI: 10.1039/d1an00370d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heterogeneous stationary phase chemistry causes chromatographic tailing that lowers separation efficiency and complicates optimizing mobile phase conditions. Model-free metrics are attractive for assessing optimal separation conditions due to the low quantity of information required, but often do not reveal underlying mechanisms that cause tailing, for example, heterogeneous retention modes. We report a new metric, which we call the Distribution Function Ratio (DFR), based on a graphical comparison between the chromatogram and Gaussian cumulative distribution functions, achieving correspondence to ground truth surface dynamics with a single chromatogram. Using a Monte Carlo framework, we show that the DFR can predict the prevalence of heterogeneous retention modes with high precision when the relative desorption rate between modes is known, as in during surface dynamics experiments. Ground truth comparisons reveal that the DFR outperforms both the asymmetry factor and skewness by yielding a one-to-one correspondence with heterogeneous retention mode prevalence over a broad range of experimentally realistic values. Perhaps of more value, we illustrate that the DFR, when combined with the asymmetry factor and skewness, can estimate microscopic surface dynamics, providing valuable insights into surface chemistry using existing chromatographic instrumentation. Connecting ensemble results to microscopic quantities through the lens of simulation establishes a new chemistry-driven route to measuring and advancing separations.
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Affiliation(s)
- Logan D C Bishop
- Department of Chemistry, Rice University, Houston, Texas 77251, USA.
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9
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Meazza M, Cruz CM, Ortuño AM, Cuerva JM, Crovetto L, Rios R. Studying the reactivity of alkyl substituted BODIPYs: first enantioselective addition of BODIPY to MBH carbonates. Chem Sci 2021; 12:4503-4508. [PMID: 34163715 PMCID: PMC8179495 DOI: 10.1039/d0sc06574a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/03/2021] [Indexed: 12/27/2022] Open
Abstract
The first enantioselective addition of alkyl BODIPYs to Morita-Baylis-Hillman (MBH) carbonates is reported. This is the first reported enantioselective methodology using the methylene position of BODIPYs as a nucleophile. The reaction is efficiently catalyzed by cinchona alkaloids, achieving high enantioselectivities and total diastereoselectivity. The use of cinchona alkaloid pseudo enantiomers (chinine/cinchonine) allows us to obtain both pairs of enantiomers in similar yields and enantioselectivities, a common issue in this type of reaction. The photophysical study of these dyes (absorption and fluorescence) has been performed in order to determine their parameters and explore future possible application in bioimaging. In addition, electronic circular dichroism (ECD) studies supported by time-dependent density functional theory (TD-DFT) calculations were also performed.
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Affiliation(s)
- Marta Meazza
- Faculty of Engineering & Physical Sciences, University of Southampton Highfield Campus Southampton SO17 1BJ UK
| | - Carlos M Cruz
- Departamento de Química Orgánica, Facultad de Ciencias, Unidad de Excelencia de Química Aplicada a la Biomedicina y Medioambiente (UEQ), Universidad de Granada Campus Fuentenueva 18071 Granada Spain
| | - Ana M Ortuño
- Departamento de Química Orgánica, Facultad de Ciencias, Unidad de Excelencia de Química Aplicada a la Biomedicina y Medioambiente (UEQ), Universidad de Granada Campus Fuentenueva 18071 Granada Spain
| | - Juan M Cuerva
- Departamento de Química Orgánica, Facultad de Ciencias, Unidad de Excelencia de Química Aplicada a la Biomedicina y Medioambiente (UEQ), Universidad de Granada Campus Fuentenueva 18071 Granada Spain
| | - Luis Crovetto
- Departamento de Fisicoquímica, Facultad de Farmacia, Unidad de Excelencia de Química Aplicada a la Biomedicina y Medioambiente (UEQ), Universidad de Granada Campus Cartuja 18071 Granada Spain
| | - Ramon Rios
- Faculty of Engineering & Physical Sciences, University of Southampton Highfield Campus Southampton SO17 1BJ UK
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10
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Armstrong MJ, Rodriguez JB, Dahl P, Salamon P, Hess H, Katira P. Power Law Behavior in Protein Desorption Kinetics Originating from Sequential Binding and Unbinding. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13527-13534. [PMID: 33152250 DOI: 10.1021/acs.langmuir.0c02260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The study of protein adsorption at the single molecule level has recently revealed that the adsorption is reversible, but with a long-tailed residence time distribution which can be approximated with a sum of exponential functions putatively related to distinct adsorption sites. Here it is proposed that the shape of the residence time distribution results from an adsorption process with sequential and reversible steps that contribute to overall binding strength resembling "zippering". In this model, the survival function of the residence time distribution of single proteins varies from an exponential distribution for a single adsorption step to a power law distribution with exponent -1/2 for a large number of adsorption steps. The adsorption of fluorescently labeled fibrinogen to glass surfaces is experimentally studied with single molecule imaging. The experimental residence time distribution can be readily fit by the proposed model. This demonstrates that the observed long residence times can arise from stepwise adsorption rather than rare but strong binding sites and provides guidance for the control of protein adsorption to biomaterials.
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Affiliation(s)
- Megan J Armstrong
- Department of Biomedical Engineering, Columbia University, New York, New York 10027, United States
| | - Juan B Rodriguez
- Department of Biomedical Engineering, Columbia University, New York, New York 10027, United States
| | - Peter Dahl
- Department of Mechanical Engineering, San Diego State University, San Diego, California 98182, United States
| | - Peter Salamon
- Department of Mathematics and Statistics and Viral Information Institute, San Diego State University, San Diego, California 98182, United States
| | - Henry Hess
- Department of Biomedical Engineering, Columbia University, New York, New York 10027, United States
| | - Parag Katira
- Department of Mechanical Engineering, San Diego State University, San Diego, California 98182, United States
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11
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Calabrase W, Bishop LDC, Dutta C, Misiura A, Landes CF, Kisley L. Transforming Separation Science with Single-Molecule Methods. Anal Chem 2020; 92:13622-13629. [PMID: 32936608 DOI: 10.1021/acs.analchem.0c02572] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Empirical optimization of the multiscale parameters underlying chromatographic and membrane separations leads to enormous resource waste and production costs. A bottom-up approach to understand the physical phenomena underlying challenges in separations is possible with single-molecule observations of solute-stationary phase interactions. We outline single-molecule fluorescence techniques that can identify key interactions under ambient conditions. Next, we describe how studying increasingly complex samples heightens the relevance of single-molecule results to industrial applications. Finally, we illustrate how separation methods that have not been studied at the single-molecule scale can be advanced, using chiral chromatography as an example case. We hope new research directions based on a molecular approach to separations will emerge based on the ideas, technologies, and open scientific questions presented in this Perspective.
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Affiliation(s)
- William Calabrase
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Logan D C Bishop
- Department of Chemistry, Rice University, Houston, Texas 77251, United States
| | - Chayan Dutta
- Department of Chemistry, Rice University, Houston, Texas 77251, United States
| | - Anastasiia Misiura
- Department of Chemistry, Rice University, Houston, Texas 77251, United States
| | - Christy F Landes
- Department of Chemistry, Rice University, Houston, Texas 77251, United States.,Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77251, United States.,Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77251, United States.,Smalley-Curl Institute, Rice University, Houston, Texas 77251, United States
| | - Lydia Kisley
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106, United States.,Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
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12
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Bishop LD, Misiura A, Moringo NA, Landes CF. Unraveling peak asymmetry in chromatography through stochastic theory powered Monte Carlo simulations. J Chromatogr A 2020; 1625:461323. [DOI: 10.1016/j.chroma.2020.461323] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 12/29/2022]
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13
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Traeger JC, Schwartz DK. Interplay of electrostatic repulsion and surface grafting density on surface-mediated DNA hybridization. J Colloid Interface Sci 2020; 566:369-374. [DOI: 10.1016/j.jcis.2020.01.070] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 12/14/2022]
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14
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Recent advances in optical microscopic methods for single-particle tracking in biological samples. Anal Bioanal Chem 2019; 411:4445-4463. [PMID: 30790020 DOI: 10.1007/s00216-019-01638-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 12/20/2018] [Accepted: 01/23/2019] [Indexed: 12/31/2022]
Abstract
With the rapid development of optical microscopic techniques, explorations on the chemical and biological properties of target objects in biological samples at single-molecule/particle level have received great attention recently. In the past decades, various powerful techniques have been developed for single-particle tracking (SPT) in biological samples. In this review, we summarize the commonly used optical microscopic methods for SPT, such as total internal reflection fluorescence microscopy (TIRFM), super-resolution fluorescence microscopy (SRM), dark-field optical microscopy (DFM), total internal reflection scattering microscopy (TIRSM), and differential interference contrast microscopy (DICM). We then discuss the image processing and data analysis methods, including particle localization, trajectory reconstruction, and diffusion behavior analysis. The application of SPT on the cell membrane, within the cell, and the cellular invading process of viruses are introduced. Finally, the challenges and prospects of optical microscopic technologies for SPT are delineated.
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15
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Niu Q, Wang D. Probing the polymer anomalous dynamics at solid/liquid interfaces at the single-molecule level. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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16
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Žuvela P, Skoczylas M, Jay Liu J, Ba Czek T, Kaliszan R, Wong MW, Buszewski B, Héberger K. Column Characterization and Selection Systems in Reversed-Phase High-Performance Liquid Chromatography. Chem Rev 2019; 119:3674-3729. [PMID: 30604951 DOI: 10.1021/acs.chemrev.8b00246] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Reversed-phase high-performance liquid chromatography (RP-HPLC) is the most popular chromatographic mode, accounting for more than 90% of all separations. HPLC itself owes its immense popularity to it being relatively simple and inexpensive, with the equipment being reliable and easy to operate. Due to extensive automation, it can be run virtually unattended with multiple samples at various separation conditions, even by relatively low-skilled personnel. Currently, there are >600 RP-HPLC columns available to end users for purchase, some of which exhibit very large differences in selectivity and production quality. Often, two similar RP-HPLC columns are not equally suitable for the requisite separation, and to date, there is no universal RP-HPLC column covering a variety of analytes. This forces analytical laboratories to keep a multitude of diverse columns. Therefore, column selection is a crucial segment of RP-HPLC method development, especially since sample complexity is constantly increasing. Rationally choosing an appropriate column is complicated. In addition to the differences in the primary intermolecular interactions with analytes of the dispersive (London) type, individual columns can also exhibit a unique character owing to specific polar, hydrogen bond, and electron pair donor-acceptor interactions. They can also vary depending on the type of packing, amount and type of residual silanols, "end-capping", bonding density of ligands, and pore size, among others. Consequently, the chromatographic performance of RP-HPLC systems is often considerably altered depending on the selected column. Although a wide spectrum of knowledge is available on this important subject, there is still a lack of a comprehensive review for an objective comparison and/or selection of chromatographic columns. We aim for this review to be a comprehensive, authoritative, critical, and easily readable monograph of the most relevant publications regarding column selection and characterization in RP-HPLC covering the past four decades. Future perspectives, which involve the integration of state-of-the-art molecular simulations (molecular dynamics or Monte Carlo) with minimal experiments, aimed at nearly "experiment-free" column selection methodology, are proposed.
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Affiliation(s)
- Petar Žuvela
- Department of Chemistry , National University of Singapore , Singapore 117543 , Singapore
| | - Magdalena Skoczylas
- Department of Environmental Chemistry and Bioanalytics, Center for Modern Interdisciplinary Technologies , Nicolaus Copernicus University , Wileńska 4 , 87-100 Toruń , Poland
| | - J Jay Liu
- Department of Chemical Engineering , Pukyong National University , 365 Sinseon-ro , Nam-gu, 48-513 Busan , Korea
| | | | | | - Ming Wah Wong
- Department of Chemistry , National University of Singapore , Singapore 117543 , Singapore
| | - Bogusław Buszewski
- Department of Environmental Chemistry and Bioanalytics, Center for Modern Interdisciplinary Technologies , Nicolaus Copernicus University , Wileńska 4 , 87-100 Toruń , Poland
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17
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Bishop LDC, Landes CF. From a Protein's Perspective: Elution at the Single-Molecule Level. Acc Chem Res 2018; 51:2247-2254. [PMID: 30132321 DOI: 10.1021/acs.accounts.8b00211] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Column chromatography is a widely used analytical technique capable of identifying and isolating a desired chemical species from a more complicated mixture. Despite the method's prevalence, theoretical descriptions have not advanced to accommodate today's common analyte, proteins. Proteins are increasingly used as biologics, a term that refers to biological pharmaceuticals, and present new complexities for chromatographic separation. Large variations in surface charge, chemistry, and structure among protein analytes expose the limits in the current theoretical framework's ability to predict the efficiency of a column without empirical data. The bottleneck created by empirical optimization is a strong motivation for a renewed effort to achieve an in-depth understanding of the range of interactions that occur between a protein analyte and the stationary phase that together enable its selective separation from other constituents of a mixture. The physical and chemical processes that dictate the amount of time an analyte spends in the column are often abstracted by theory and treated as statistical distributions. Until recently, these distributions could not be mapped experimentally as traditional experimental techniques could not reveal underlying heterogeneity in structure, charge, and dynamics. Aligning the latest experimental and theoretical advances is thus a hurdle to be overcome so that significant progress can be made toward a predictive chromatographic theory. In this Account, we detail the work of the Landes Lab in developing single-molecule techniques that refine the stochastic theory of chromatography as a first step toward predictive chromatographic column design. We provide a brief review of the development of stochastic theory and establish a mathematical framework to put the discussed physical chemistry in context. We describe our investigations of three pertinent phenomena: mobile/stationary phase exchange, adsorption/desorption kinetics, and hindered diffusion. We highlight experimental evidence that points to nonuniform behavior. Then, we describe our work in developing single-molecule techniques that can evaluate these effects on a protein-by-protein basis. We highlight two developments: fast imaging via super temporal-resolved microscopy (STReM) and visualizing diffusion within pores via a combination of fluorescence correlation spectroscopy and super-resolution optical fluctuation imaging (fcsSOFI). Both methods offer new ways to study chromatographic elution at the single-protein level. Such methods can identify the rare heterogeneities that prevent efficient separations and advance the field closer to predictively optimized protein separations.
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18
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Moringo NA, Shen H, Bishop LDC, Wang W, Landes CF. Enhancing Analytical Separations Using Super-Resolution Microscopy. Annu Rev Phys Chem 2018; 69:353-375. [PMID: 29490205 DOI: 10.1146/annurev-physchem-052516-045018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Super-resolution microscopy is becoming an invaluable tool to investigate structure and dynamics driving protein interactions at interfaces. In this review, we highlight the applications of super-resolution microscopy for quantifying the physics and chemistry that occur between target proteins and stationary-phase supports during chromatographic separations. Our discussion concentrates on the newfound ability of super-resolved single-protein spectroscopy to inform theoretical parameters via quantification of adsorption-desorption dynamics, protein unfolding, and nanoconfined transport.
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Affiliation(s)
| | - Hao Shen
- Department of Chemistry, Rice University, Houston, Texas 77251, USA;
| | - Logan D C Bishop
- Department of Chemistry, Rice University, Houston, Texas 77251, USA;
| | - Wenxiao Wang
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77251, USA
| | - Christy F Landes
- Department of Chemistry, Rice University, Houston, Texas 77251, USA; .,Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77251, USA.,Smalley-Curl Institute, Rice University, Houston, Texas 77251, USA
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19
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Shen H, Tauzin LJ, Baiyasi R, Wang W, Moringo N, Shuang B, Landes CF. Single Particle Tracking: From Theory to Biophysical Applications. Chem Rev 2017; 117:7331-7376. [PMID: 28520419 DOI: 10.1021/acs.chemrev.6b00815] [Citation(s) in RCA: 264] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
After three decades of developments, single particle tracking (SPT) has become a powerful tool to interrogate dynamics in a range of materials including live cells and novel catalytic supports because of its ability to reveal dynamics in the structure-function relationships underlying the heterogeneous nature of such systems. In this review, we summarize the algorithms behind, and practical applications of, SPT. We first cover the theoretical background including particle identification, localization, and trajectory reconstruction. General instrumentation and recent developments to achieve two- and three-dimensional subdiffraction localization and SPT are discussed. We then highlight some applications of SPT to study various biological and synthetic materials systems. Finally, we provide our perspective regarding several directions for future advancements in the theory and application of SPT.
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Affiliation(s)
- Hao Shen
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Lawrence J Tauzin
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Rashad Baiyasi
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Wenxiao Wang
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Nicholas Moringo
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Bo Shuang
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
| | - Christy F Landes
- Department of Chemistry and ‡Department of Electrical and Computer Engineering, §Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
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20
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Kisley L, Patil U, Dhamane S, Kourentzi K, Tauzin LJ, Willson RC, Landes CF. Competitive multicomponent anion exchange adsorption of proteins at the single molecule level. Analyst 2017; 142:3127-3131. [DOI: 10.1039/c7an00701a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Super-resolution imaging of multicomponent, competitive adsorption demonstrates that competitors block certain ligands from the analyte without changing analyte adsorption kinetics.
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Affiliation(s)
- Lydia Kisley
- Department of Chemistry
- Rice University
- Houston
- USA
| | - Ujwal Patil
- Department of Biology & Biochemistry
- University of Houston
- Houston
- USA
| | - Sagar Dhamane
- Department of Biology & Biochemistry
- University of Houston
- Houston
- USA
| | - Katerina Kourentzi
- Department of Chemical & Biomolecular Engineering
- University of Houston
- Houston
- USA
| | | | - Richard C. Willson
- Department of Chemical & Biomolecular Engineering
- University of Houston
- Houston
- USA
- Department of Biology & Biochemistry
| | - Christy F. Landes
- Department of Chemistry
- Rice University
- Houston
- USA
- Department of Electrical and Computer Engineering
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21
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Wang W, Shen H, Shuang B, Hoener BS, Tauzin LJ, Moringo NA, Kelly KF, Landes CF. Super Temporal-Resolved Microscopy (STReM). J Phys Chem Lett 2016; 7:4524-4529. [PMID: 27797527 DOI: 10.1021/acs.jpclett.6b02098] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Super-resolution microscopy typically achieves high spatial resolution, but the temporal resolution remains low. We report super temporal-resolved microscopy (STReM) to improve the temporal resolution of 2D super-resolution microscopy by a factor of 20 compared to that of the traditional camera-limited frame rate. This is achieved by rotating a phase mask in the Fourier plane during data acquisition and then recovering the temporal information by fitting the point spread function (PSF) orientations. The feasibility of this technique is verified with both simulated and experimental 2D adsorption/desorption and 2D emitter transport. When STReM is applied to measure protein adsorption at a glass surface, previously unseen dynamics are revealed.
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Affiliation(s)
- Wenxiao Wang
- Department of Electrical and Computer Engineering, Rice University , MS 366, Houston, Texas 77251-1892, United States
| | - Hao Shen
- Department of Chemistry, Rice University , MS 60, Houston, Texas 77251-1892, United States
| | - Bo Shuang
- Department of Chemistry, Rice University , MS 60, Houston, Texas 77251-1892, United States
| | - Benjamin S Hoener
- Department of Chemistry, Rice University , MS 60, Houston, Texas 77251-1892, United States
| | - Lawrence J Tauzin
- Department of Chemistry, Rice University , MS 60, Houston, Texas 77251-1892, United States
| | - Nicholas A Moringo
- Department of Chemistry, Rice University , MS 60, Houston, Texas 77251-1892, United States
| | - Kevin F Kelly
- Department of Electrical and Computer Engineering, Rice University , MS 366, Houston, Texas 77251-1892, United States
| | - Christy F Landes
- Department of Electrical and Computer Engineering, Rice University , MS 366, Houston, Texas 77251-1892, United States
- Department of Chemistry, Rice University , MS 60, Houston, Texas 77251-1892, United States
- Smalley-Curl Institute, Rice University , Houston, Texas 77251, United States
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22
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Shuang B, Wang W, Shen H, Tauzin LJ, Flatebo C, Chen J, Moringo NA, Bishop LDC, Kelly KF, Landes CF. Generalized recovery algorithm for 3D super-resolution microscopy using rotating point spread functions. Sci Rep 2016; 6:30826. [PMID: 27488312 PMCID: PMC4973222 DOI: 10.1038/srep30826] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/11/2016] [Indexed: 01/17/2023] Open
Abstract
Super-resolution microscopy with phase masks is a promising technique for 3D imaging and tracking. Due to the complexity of the resultant point spread functions, generalized recovery algorithms are still missing. We introduce a 3D super-resolution recovery algorithm that works for a variety of phase masks generating 3D point spread functions. A fast deconvolution process generates initial guesses, which are further refined by least squares fitting. Overfitting is suppressed using a machine learning determined threshold. Preliminary results on experimental data show that our algorithm can be used to super-localize 3D adsorption events within a porous polymer film and is useful for evaluating potential phase masks. Finally, we demonstrate that parallel computation on graphics processing units can reduce the processing time required for 3D recovery. Simulations reveal that, through desktop parallelization, the ultimate limit of real-time processing is possible. Our program is the first open source recovery program for generalized 3D recovery using rotating point spread functions.
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Affiliation(s)
- Bo Shuang
- Department of Chemistry, Rice University, Houston, TX 77251, USA
| | - Wenxiao Wang
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251, USA
| | - Hao Shen
- Department of Chemistry, Rice University, Houston, TX 77251, USA
| | | | | | - Jianbo Chen
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251, USA
| | | | | | - Kevin F. Kelly
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251, USA
| | - Christy F. Landes
- Department of Chemistry, Rice University, Houston, TX 77251, USA
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251, USA
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23
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Wei L, Ye Z, Luo W, Chen B, Xiao L. Redistribution of fluorescent molecules at the solid/liquid interface with total internal reflection illumination. Talanta 2016; 155:229-34. [PMID: 27216678 DOI: 10.1016/j.talanta.2016.04.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 04/06/2016] [Accepted: 04/09/2016] [Indexed: 10/21/2022]
Abstract
Many intriguing physical and chemical processes commonly take place at the solid/liquid interface. Total internal reflection illumination, together with single molecule spectroscopy, provides a robust platform for the selective exploration of kinetic processes close the interface. With these techniques, it was observed that the distribution of Rhodamine B molecules close to a solid/liquid interface could be regulated in a photo-induced route. The laser-induced repulsion force at this interface is enough to compromise the Brownian diffusion of single molecules in a range of several hundred nanometers normal to the solid/liquid interface. This observation is fundamentally and practically interesting because moderate laser intensity is enough to initiate this repulsion effect. Therefore, it might display extensive applications in the development of photo-modulation technique with high throughput capability.
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Affiliation(s)
- Lin Wei
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Zhongju Ye
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Wenjuan Luo
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Bo Chen
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Lehui Xiao
- Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, PR China.
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24
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Pasti L, Marchetti N, Guzzinati R, Catani M, Bosi V, Dondi F, Sepsey A, Felinger A, Cavazzini A. Microscopic models of liquid chromatography: From ensemble-averaged information to resolution of fundamental viewpoint at single-molecule level. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2015.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Faulón Marruecos D, Kastantin M, Schwartz DK, Kaar JL. Dense Poly(ethylene glycol) Brushes Reduce Adsorption and Stabilize the Unfolded Conformation of Fibronectin. Biomacromolecules 2016; 17:1017-25. [PMID: 26866385 DOI: 10.1021/acs.biomac.5b01657] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Polymer brushes, in which polymers are end-tethered densely to a grafting surface, are commonly proposed for use as stealth coatings for various biomaterials. However, although their use has received considerable attention, a mechanistic understanding of the impact of brush properties on protein adsorption and unfolding remains elusive. We investigated the effect of the grafting density of poly(ethylene glycol) (PEG) brushes on the interactions of the brush with fibronectin (FN) using high-throughput single-molecule tracking methods, which directly measure protein adsorption and unfolding within the brush. We observed that, as grafting density increased, the rate of FN adsorption decreased; however, surface-adsorbed FN unfolded more readily, and unfolded molecules were retained on the surface for longer residence times relative to those of folded molecules. These results, which are critical for the rational design of PEG brushes, suggest that there is a critical balance between protein adsorption and conformation that underlies the utility of such brushes in physiological environments.
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Affiliation(s)
- David Faulón Marruecos
- Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States
| | - Mark Kastantin
- Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States
| | - Joel L Kaar
- Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States
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26
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Weltz JS, Schwartz DK, Kaar JL. Surface-Mediated Protein Unfolding as a Search Process for Denaturing Sites. ACS NANO 2016; 10:730-738. [PMID: 26580418 DOI: 10.1021/acsnano.5b05787] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surface-induced protein denaturation has important implications for the development of materials that are resistant and/or innocuous to biomolecules. Here, we studied the mechanism of lysozyme (T4L) unfolding on fused silica (FS) using single-molecule methods that provided direct insight into the cause of denaturation. Unfolding of T4L was monitored by Förster resonance energy transfer while simultaneously tracking the adsorption, diffusion, and desorption of individual molecules at the solid-solution interface. Results of high-throughput single-molecule analysis suggested that the unfolding of T4L on FS was mediated by surface diffusion and occurred on isolated nanoscale sites, which were relatively rare and distinct from the majority of the surface. These observations suggest that surface-mediated protein unfolding is a search process that is based on the exploration for denaturing sites by the protein. Ultimately, these findings have important implications for the design of protein-compatible surfaces.
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Affiliation(s)
- James S Weltz
- Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States
| | - Joel L Kaar
- Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States
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27
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Cai Y, Schwartz DK. Influence of Protein Surface Coverage on Anomalously Strong Adsorption Sites. ACS APPLIED MATERIALS & INTERFACES 2016; 8:511-520. [PMID: 26651508 DOI: 10.1021/acsami.5b09459] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Serum albumin is commonly used as a blocking agent to reduce nonspecific protein adsorption in bioassays and biodevices; however, the details of this process remain poorly understood. Using single molecule techniques, we investigated the dynamics of human serum albumin (HSA) on four model surfaces as a function of protein concentration. By constructing super-resolution maps, identifying anomalously strong adsorption sites, and quantifying surface heterogeneity, we found that the concentration required for site blocking varied dramatically with surface chemistry. When expressed in terms of protein surface coverage, however, a more consistent picture emerged, where a significant fraction of strong sites were passivated at a fractional coverage of 10(-4). On fused silica (FS), "non-fouling" oligo (ethylene glycol) functionalized FS, and hydrophobically modified FS, a modest additional site blocking effect continued at higher coverage. However, on amine-functionalized surfaces, the surface heterogeneity exhibited a minimum at a coverage of ∼10(-4). Using intermolecular Förster resonance energy transfer (FRET), we determined that new anomalous strong sites were created at higher coverage on amine surfaces and that adsorption to these sites was associated with protein-protein interactions, i.e., surface-induced aggregation.
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Affiliation(s)
- Yu Cai
- Department of Chemical and Biological Engineering, University of Colorado Boulder , 596 UCB, Boulder, Colorado 80309-0596, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder , 596 UCB, Boulder, Colorado 80309-0596, United States
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28
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Tauzin LJ, Shen H, Moringo NA, Roddy MH, Bothof CA, Griesgraber GW, McNulty AK, Rasmussen JK, Landes CF. Variable surface transport modalities on functionalized nylon films revealed with single molecule spectroscopy. RSC Adv 2016. [DOI: 10.1039/c5ra25592a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Functionalization of separation membranes with ion-exchange ligands allows control of the surface mobility of protein molecules facilitating optimized membrane design.
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Affiliation(s)
| | - Hao Shen
- Department of Chemistry
- Rice University
- Houston
- USA
| | | | | | - Cathy A. Bothof
- 3M Corporate Research Laboratories
- 3M Center 201-3E-03
- St. Paul
- USA
| | | | - Amy K. McNulty
- 3M Corporate Research Laboratories
- 3M Center 201-3E-03
- St. Paul
- USA
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29
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Kisley L, Poongavanam MV, Kourentzi K, Willson RC, Landes CF. pH-dependence of single-protein adsorption and diffusion at a liquid chromatographic interface. J Sep Sci 2015; 39:682-8. [DOI: 10.1002/jssc.201500809] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/04/2015] [Accepted: 09/05/2015] [Indexed: 12/22/2022]
Affiliation(s)
- Lydia Kisley
- Department of Chemistry; Rice University; Houston TX USA
| | | | - Katerina Kourentzi
- Department of Chemical & Biomolecular Engineering; University of Houston; Houston TX USA
| | - Richard C. Willson
- Department of Biology & Biochemistry; University of Houston; Houston TX USA
- Department of Chemical & Biomolecular Engineering; University of Houston; Houston TX USA
- Houston Methodist Research Institute; Houston TX USA
- Centro de Biotecnología FEMSA, Departamento de Biotecnología e Ingeniería de Alimentos; Tecnológico de Monterrey; Monterrey NL Mexico
| | - Christy F. Landes
- Department of Chemistry; Rice University; Houston TX USA
- Department of Electrical and Computer Engineering; Rice University; Houston TX USA
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30
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Langdon BB, Kastantin M, Schwartz DK. Surface Chemistry Influences Interfacial Fibrinogen Self-Association. Biomacromolecules 2015; 16:3201-8. [DOI: 10.1021/acs.biomac.5b00869] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Blake B. Langdon
- Department of Chemical and
Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Mark Kastantin
- Department of Chemical and
Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Daniel K. Schwartz
- Department of Chemical and
Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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31
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Mabry JN, Kastantin M, Schwartz DK. Capturing Conformation-Dependent Molecule-Surface Interactions When Surface Chemistry Is Heterogeneous. ACS NANO 2015; 9:7237-7247. [PMID: 26079177 DOI: 10.1021/acsnano.5b02071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Molecular building blocks, such as carbon nanotubes and DNA origami, can be fully integrated into electronic and optical devices if they can be assembled on solid surfaces using biomolecular interactions. However, the conformation and functionality of biomolecules depend strongly on the local chemical environment, which is highly heterogeneous near a surface. To help realize the potential of biomolecular self-assembly, we introduce here a technique to spatially map molecular conformations and adsorption, based on single-molecule fluorescence microscopy. On a deliberately patterned surface, with regions of varying hydrophobicity, we characterized the conformations of adsorbed helicogenic alanine-lysine copeptides using Förster resonance energy transfer. The peptides adopted helical conformations on hydrophilic regions of the surface more often than on hydrophobic regions, consistent with previous ensemble-averaged observations of α-helix surface stability. Interestingly, this dependence on surface chemistry was not due to surface-induced unfolding, as the apparent folding and unfolding dynamics were usually much slower than desorption. The most significant effect of surface chemistry was on the adsorption rate of molecules as a function of their initial conformational state. In particular, regions with higher adsorption rates attracted more molecules in compact, disordered coil states, and this difference in adsorption rates dominated the average conformation of the ensemble. The correlation between adsorption rate and average conformation was also observed on nominally uniform surfaces. Spatial variations in the functional state of adsorbed molecules would strongly affect the success rates of surface-based molecular assembly and can be fully understood using the approach developed in this work.
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Affiliation(s)
- Joshua N Mabry
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Mark Kastantin
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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32
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McUmber AC, Randolph TW, Schwartz DK. Electrostatic Interactions Influence Protein Adsorption (but Not Desorption) at the Silica-Aqueous Interface. J Phys Chem Lett 2015; 6:2583-7. [PMID: 26266737 DOI: 10.1021/acs.jpclett.5b00933] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
High-throughput single-molecule total internal reflection fluorescence microscopy was used to investigate the effects of pH and ionic strength on bovine serum albumin (BSA) adsorption, desorption, and interfacial diffusion at the aqueous-fused silica interface. At high pH and low ionic strength, negatively charged BSA adsorbed slowly to the negatively charged fused silica surface. At low pH and low ionic strength, where BSA was positively charged, or in solutions at higher ionic strength, adsorption was approximately 1000 times faster. Interestingly, neither surface residence times nor the interfacial diffusion coefficients of BSA were influenced by pH or ionic strength. These findings suggested that adsorption kinetics were dominated by energy barriers associated with electrostatic interactions, but once adsorbed, protein-surface interactions were dominated by short-range nonelectrostatic interactions. These results highlight the ability of single-molecule techniques to isolate elementary processes (e.g., adsorption and desorption) under steady-state conditions, which would be impossible to measure using ensemble-averaging methods.
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Affiliation(s)
- Aaron C McUmber
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Theodore W Randolph
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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33
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Chin HY, Wang D, Schwartz DK. Dynamic Molecular Behavior on Thermoresponsive Polymer Brushes. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00729] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Huai-Ying Chin
- Department of Chemical and
Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Dapeng Wang
- Department of Chemical and
Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Daniel K. Schwartz
- Department of Chemical and
Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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Nelson N, Schwartz DK. Unbiased Clustering of Molecular Dynamics for Spatially Resolved Analysis of Chemically Heterogeneous Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:6099-6106. [PMID: 26001158 DOI: 10.1021/acs.langmuir.5b01251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A technique is described for resolving and interpreting molecular interactions with a chemically heterogeneous surface. Using total internal reflection fluorescence microscopy, dynamic single molecule trajectories were accumulated simultaneously for fluorescently labeled fatty acid (interacting primarily via hydrophobic interactions) and dextran (interacting via hydrogen-bonding interactions) probe molecules at the interface between an aqueous solvent and a photopatterned solid surface with distinct regions of amine-terminated and poly(ethylene glycol) self-assembled monolayers. Using dynamic properties of the probe molecules (adsorption rate, surface diffusion coefficient, residence time), an unsupervised Gaussian mixture model algorithm was used to identify areas of the surface that were chemically related to each other, and the dynamic behaviors of the probe molecules were studied statistically on these distinct regions. The dynamic data were compared to data from homogeneous surfaces of known chemistry to provide a chemical identification of each location on the surface. Spatial maps were also constructed, allowing for spatial visualization of surface chemistry on a hydrophilic substrate. This work enables the direct study of interactions between single-molecule probes and distinct surface chemistries, even in the presence of spatial heterogeneity, without human bias, assumptions about surface structure, or model-dependent analysis.
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Affiliation(s)
- Nathaniel Nelson
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
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Mabry JN, Schwartz DK. Tuning the Flight Length of Molecules Diffusing on a Hydrophobic Surface. J Phys Chem Lett 2015; 6:2065-2069. [PMID: 26266503 DOI: 10.1021/acs.jpclett.5b00799] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Transport at solid-liquid interfaces is critical to self-assembly, biosensing, and heterogeneous catalysis, but surface diffusion remains difficult to characterize and rationally manipulate, due to the inherent heterogeneity of adsorption on solid surfaces. Using single-molecule tracking, we characterized the diffusion of a fluorescent long-chain surfactant on a hydrophobic surface, which involved periods of confinement alternating with bulk-mediated "flights". The concentration of methanol in solution was varied to tune the strength of the hydrophobic surface-molecule interaction. The frequency of confinement had a nonmonotonic dependence on methanol concentration that reflected the relative influence of anomalously strong adsorption sites. By carefully accounting for the effect of this surface heterogeneity, we demonstrated that flight lengths increased monotonically as the hydrophobic attraction decreased, in agreement with theoretical predictions for bulk-mediated surface diffusion. The theory provided an accurate description of surface diffusion, despite the system being heterogeneous, and can be leveraged to optimize molecular search and assembly processes.
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Affiliation(s)
- Joshua N Mabry
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309-0596, United States
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Langdon BB, Mirhossaini RB, Mabry JN, Sriram I, Lajmi A, Zhang Y, Rojas OJ, Schwartz DK. Single-molecule resolution of protein dynamics on polymeric membrane surfaces: the roles of spatial and population heterogeneity. ACS APPLIED MATERIALS & INTERFACES 2015; 7:3607-3617. [PMID: 25611782 DOI: 10.1021/am507730k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although polymeric membranes are widely used in the purification of protein pharmaceuticals, interactions between biomolecules and membrane surfaces can lead to reduced membrane performance and damage to the product. In this study, single-molecule fluorescence microscopy provided direct observation of bovine serum albumin (BSA) and human monoclonal antibody (IgG) dynamics at the interface between aqueous buffer and polymeric membrane materials including regenerated cellulose and unmodified poly(ether sulfone) (PES) blended with either polyvinylpyrrolidone (PVP), polyvinyl acetate-co-polyvinylpyrrolidone (PVAc-PVP), or polyethylene glycol methacrylate (PEGM) before casting. These polymer surfaces were compared with model surfaces composed of hydrophilic bare fused silica and hydrophobic trimethylsilane-coated fused silica. At extremely dilute protein concentrations (10(-3)-10(-7) mg/mL), protein surface exchange was highly dynamic with protein monomers desorbing from the surface within ∼1 s after adsorption. Protein oligomers (e.g., nonspecific dimers, trimers, or larger aggregates), although less common, remained on the surface for 5 times longer than monomers. Using newly developed super-resolution methods, we could localize adsorption sites with ∼50 nm resolution and quantify the spatial heterogeneity of the various surfaces. On a small anomalous subset of the adsorption sites, proteins adsorbed preferentially and tended to reside for significantly longer times (i.e., on "strong" sites). Proteins resided for shorter times overall on surfaces that were more homogeneous and exhibited fewer strong sites (e.g., PVAc-PVP/PES). We propose that strong surface sites may nucleate protein aggregation, initiated preferentially by protein oligomers, and accelerate ultrafiltration membrane fouling. At high protein concentrations (0.3-1.0 mg/mL), fewer strong adsorption sites were observed, and surface residence times were reduced. This suggests that at high concentrations, adsorbed proteins block strong sites from further protein adsorption. Importantly, this demonstrates that strong binding sites can be modified by changing solution conditions. Membrane surfaces are intrinsically heterogeneous; by employing single-molecule techniques, we have provided a new framework for understanding protein interactions with such surfaces.
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Affiliation(s)
- Blake B Langdon
- Department of Chemical and Biological Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States
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Affiliation(s)
- Lydia Kisley
- Department of Chemistry and Department of Electrical and Computer
Engineering,
Rice Quantum Institute, Rice University, 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department of Chemistry and Department of Electrical and Computer
Engineering,
Rice Quantum Institute, Rice University, 6100 Main Street, MS-60, Houston, Texas 77005, United States
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