1
|
Bolivar JM, Woodley JM, Fernandez-Lafuente R. Is enzyme immobilization a mature discipline? Some critical considerations to capitalize on the benefits of immobilization. Chem Soc Rev 2022; 51:6251-6290. [PMID: 35838107 DOI: 10.1039/d2cs00083k] [Citation(s) in RCA: 113] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Enzyme immobilization has been developing since the 1960s and although many industrial biocatalytic processes use the technology to improve enzyme performance, still today we are far from full exploitation of the field. One clear reason is that many evaluate immobilization based on only a few experiments that are not always well-designed. In contrast to many other reviews on the subject, here we highlight the pitfalls of using incorrectly designed immobilization protocols and explain why in many cases sub-optimal results are obtained. We also describe solutions to overcome these challenges and come to the conclusion that recent developments in material science, bioprocess engineering and protein science continue to open new opportunities for the future. In this way, enzyme immobilization, far from being a mature discipline, remains as a subject of high interest and where intense research is still necessary to take full advantage of the possibilities.
Collapse
Affiliation(s)
- Juan M Bolivar
- FQPIMA group, Chemical and Materials Engineering Department, Faculty of Chemical Sciences, Complutense University of Madrid, Madrid, 28040, Spain
| | - John M Woodley
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
| | - Roberto Fernandez-Lafuente
- Departamento de Biocatálisis. ICP-CSIC, C/Marie Curie 2, Campus UAM-CSIC Cantoblanco, Madrid 28049, Spain. .,Center of Excellence in Bionanoscience Research, External Scientific Advisory Academic, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| |
Collapse
|
2
|
Misiura A, Dutta C, Leung W, Zepeda O J, Terlier T, Landes CF. The competing influence of surface roughness, hydrophobicity, and electrostatics on protein dynamics on a self-assembled monolayer. J Chem Phys 2022; 156:094707. [DOI: 10.1063/5.0078797] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Surface morphology, in addition to hydrophobic and electrostatic effects, can alter how proteins interact with solid surfaces. Understanding the heterogeneous dynamics of protein adsorption on surfaces with varying roughness is experimentally challenging. In this work, we use single-molecule fluorescence microscopy to study the adsorption of α-lactalbumin protein on the glass substrate covered with a self-assembled monolayer (SAM) with varying surface concentrations. Two distinct interaction mechanisms are observed: localized adsorption/desorption and continuous-time random walk (CTRW). We investigate the origin of these two populations by simultaneous single-molecule imaging of substrates with both bare glass and SAM-covered regions. SAM-covered areas of substrates are found to promote CTRW, whereas glass surfaces promote localized motion. Contact angle measurements and atomic force microscopy imaging show that increasing SAM concentration results in both increasing hydrophobicity and surface roughness. These properties lead to two opposing effects: increasing hydrophobicity promotes longer protein flights, but increasing surface roughness suppresses protein dynamics resulting in shorter residence times. Our studies suggest that controlling hydrophobicity and roughness, in addition to electrostatics, as independent parameters could provide a means to tune desirable or undesirable protein interactions with surfaces.
Collapse
Affiliation(s)
| | - Chayan Dutta
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
| | - Wesley Leung
- Applied Physics Graduate Program, Rice University, Houston, Texas 77005, USA
| | - Jorge Zepeda O
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
| | - Tanguy Terlier
- SIMS Laboratory, Shared Equipment Authority, Rice University, Houston, Texas 77005, USA
| | - Christy F. Landes
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
- Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, USA
- Smalley-Curl Institute, Rice University, Houston, Texas 77005, USA
| |
Collapse
|
3
|
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.
Collapse
Affiliation(s)
- Logan D C Bishop
- Department of Chemistry, Rice University, Houston, Texas 77251, USA.
| | | | | |
Collapse
|
4
|
Dong Z, Hou Y, Han W, Liu M, Wang J, Qiu Y. Protein corona-mediated transport of nanoplastics in seawater-saturated porous media. WATER RESEARCH 2020; 182:115978. [PMID: 32622130 DOI: 10.1016/j.watres.2020.115978] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/13/2020] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
The offshore aquaculture environment is a potential water area with high concentrations of tiny plastics and feeding proteins. In this study, the negatively charged bovine serum albumin (BSA) and the positively charged lysozyme (LSZ) were used to explore the effects of protein corona on the aggregation, transport, and retention of polystyrene nanoplastics (NPs; 200, 500, and 1000 nm) in sea sand saturated with seawater of 35 practical salinity units (PSU). The BSA corona, which was formed by the adsorption of BSA on the surface of NPs, drove the dispersion of NPs (200 and 500 nm) due dominantly to the induced colloidal steric hindrance. For example, the aggregate sizes of 500 nm NP decreased from 1740 ± 87 nm to 765 ± 8 nm at 40 min, which resulted in the enhanced transportation of NP. The calculated interaction energies indicated the BSA corona-induced high energy barriers (>104 KBT) between 1000 nm NPs and sand surface, demonstrating the BSA-enhanced transport of 1000 nm NPs. The mass percentage recovered from the effluent (Meff) increased from 33.4% to 61.7%. Inversely, the LSZ corona triggered the aggregation of 200 nm NPs into the large aggregates via electrostatic adsorption and bridging effect, thereby inhibiting the transport of 200 nm NPs. Nevertheless, no LSZ corona was formed on the surface of 500 and 1000 nm NPs due to extremely low protein adsorption. Accordingly, LSZ cannot affect the stability and transport of these NPs. In the diluted seawater (3.5 PSU), the strong electrostatic attraction between positively charged LSZ and 500 nm NPs significantly increased and the LSZ corona formed, which induced the aggregation of 500 nm NPs. The Meff of NPs therefore decreased from 53.1% to 11.2%. Overall, the protein corona-mediated transport of NPs in seawater-saturated porous media depends on protein type, NP size, and seawater salinity.
Collapse
Affiliation(s)
- Zhiqiang Dong
- State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Yuanzhang Hou
- State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Wenhui Han
- State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Mengping Liu
- State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Junliang Wang
- College of the Environment, Zhejiang University of Technology, Hangzhou, 310014, China
| | - Yuping Qiu
- State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
| |
Collapse
|
5
|
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]
|
6
|
Dutta C, Bishop LDC, Zepeda O J, Chatterjee S, Flatebo C, Landes CF. Imaging Switchable Protein Interactions with an Active Porous Polymer Support. J Phys Chem B 2020; 124:4412-4420. [PMID: 32441098 DOI: 10.1021/acs.jpcb.0c01807] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mechanistic details about how local physicochemistry of porous interfaces drives protein transport mechanisms are necessary to optimize biomaterial applications. Cross-linked hydrogels made of stimuli-responsive polymers have potential for active protein capture and release through tunable steric and chemical transformations. Simultaneous monitoring of dynamic changes in both protein transport and interfacial polymer structure is an experimental challenge. We use single-particle tracking (SPT) and fluorescence correlation spectroscopy Super-resolution Optical Fluctuation Imaging (fcsSOFI) to relate the switchable changes in size and structure of a pH-responsive hydrogel to the interfacial transport properties of a model protein, lysozyme. SPT analysis reveals the reversible switching of protein transport dynamics in and at the hydrogel polymer in response to pH changes. fcsSOFI allows us to relate tunable heterogeneity of the hydrogels and pores to reversible changes in the distribution of confined diffusion and adsorption/desorption. We find that physicochemical heterogeneity of the hydrogels dictates protein confinement and desorption dynamics, particularly at pH conditions in which the hydrogels are swollen.
Collapse
Affiliation(s)
- Chayan Dutta
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Logan D. C. Bishop
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Jorge Zepeda O
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Sudeshna Chatterjee
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Charlotte Flatebo
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Applied Physics Program, Rice University, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, HoustonTexas 77005, United States
| |
Collapse
|
7
|
Dutta C, Bishop LDC, Zepeda O J, Chatterjee S, Flatebo C, Landes CF. Imaging Switchable Protein Interactions With an Active Porous Polymer Support. J Phys Chem A 2020. [DOI: 10.1021/acs.jpca.0c01807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
8
|
Moringo NA, Shen H, Tauzin LJ, Wang W, Landes CF. Polymer Free Volume Effects on Protein Dynamics in Polystyrene Revealed by Single-Molecule Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2330-2338. [PMID: 32078328 DOI: 10.1021/acs.langmuir.9b03535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Protein-polymer interactions are critical to applications ranging from biomedical devices to chromatographic separations. The mechanistic relationship between the microstructure of polymer chains and protein interactions is challenging to quantify and not well studied. Here, single-molecule microscopy is used to compare the dynamics of two model proteins, α-lactalbumin and lysozyme, at the interface of uncharged polystyrene with varied molecular weights. The two proteins exhibit different surface interaction mechanisms despite having a similar size and structure. α-Lactalbumin exhibits interfacial adsorption-desorption with residence times that depend on polymer molecular weight. Lysozyme undergoes a continuous time random walk at the polystyrene surface with residence times that also depend on the molecular weight of polystyrene. Single-molecule observables suggest that the hindered continuous time random walk dynamics displayed by lysozyme are determined by the polystyrene free volume, a finding supported by thermal annealing and solvent quality studies. Hindered dynamics are dominated by short-range hydrophobic interactions where the contributions of electrostatic forces are negligible. This work establishes a relationship between the microscale structure (i.e., free volume) of polystyrene polymer chains to nanoscale interfacial protein dynamics.
Collapse
|
9
|
Warning LA, Zhang Q, Baiyasi R, Landes CF, Link S. Nanoscale Surface-Induced Unfolding of Single Fibronectin Is Restricted by Serum Albumin Crowding. J Phys Chem Lett 2020; 11:1170-1177. [PMID: 31967479 DOI: 10.1021/acs.jpclett.9b03446] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Understanding nanoscale protein conformational changes at solid-liquid interfaces is critical for predicting how proteins will impact the performance of biomaterials in vivo. Crowding is an important contributor to conformational stability. Here we apply single-molecule high resolution imaging with photobleaching to directly measure dye-conjugated fibronectin's unfolding in varying conditions of crowding with human serum albumin on aminosilanized glass. Using this approach, we identify serum albumin's crowding mechanism. We find that fibronectin achieves larger degrees of unfolding when not crowded by coadsorbed serum albumin. Serum albumin does not as effectively constrict fibronectin's conformation if it is sequentially, rather than simultaneously, introduced, suggesting that serum albumin's crowding mechanism is dependent on its ability to sterically block fibronectin's unfolding during the process of adsorption. Because fibronectin's conformation is dependent on interfacial macromolecular crowding under in vitro conditions, it is important to consider the role of in vivo crowding on protein activity.
Collapse
|
10
|
Bolivar JM, Nidetzky B. On the relationship between structure and catalytic effectiveness in solid surface-immobilized enzymes: Advances in methodology and the quest for a single-molecule perspective. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1868:140333. [PMID: 31778816 DOI: 10.1016/j.bbapap.2019.140333] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 11/05/2019] [Accepted: 11/22/2019] [Indexed: 12/31/2022]
Abstract
The integration of enzymes with solid materials is important in many biotechnological applications, including the use of immobilized enzymes for biocatalytic synthesis. The development of functional enzyme-material composites is restrained by the lack of molecular-level insight into the behavior of enzymes in confined, surface-near environments. Here, we review recent advances in surface-sensitive spectroscopic techniques that push boundaries for the determination of enzyme structure and orientation at the solid-liquid interface. We discuss recent evidence from single-molecule studies showing that analyses sensitive to the temporal and spatial heterogeneities in immobilized enzymes can succeed in disentangling the effects of conformational stability and active-site accessibility on activity. Different immobilization methods involve distinct trade-off between these effects, thus emphasizing the need for a holistic (systems) view of immobilized enzymes for the rational development of practical biocatalysts.
Collapse
Affiliation(s)
- Juan M Bolivar
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010 Graz, Austria; Austrian Centre of Industrial Biotechnology, Petersgasse 12, A-8010 Graz, Austria; Chemical and Materials Engineering Department, Complutense University of Madrid, 28040 Madrid, Spain
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010 Graz, Austria; Austrian Centre of Industrial Biotechnology, Petersgasse 12, A-8010 Graz, Austria.
| |
Collapse
|
11
|
Moringo NA, Bishop LDC, Shen H, Misiura A, Carrejo NC, Baiyasi R, Wang W, Ye F, Robinson JT, Landes CF. A mechanistic examination of salting out in protein-polymer membrane interactions. Proc Natl Acad Sci U S A 2019; 116:22938-22945. [PMID: 31659038 PMCID: PMC6859367 DOI: 10.1073/pnas.1909860116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Developing a mechanistic understanding of protein dynamics and conformational changes at polymer interfaces is critical for a range of processes including industrial protein separations. Salting out is one example of a procedure that is ubiquitous in protein separations yet is optimized empirically because there is no mechanistic description of the underlying interactions that would allow predictive modeling. Here, we investigate peak narrowing in a model transferrin-nylon system under salting out conditions using a combination of single-molecule tracking and ensemble separations. Distinct surface transport modes and protein conformational changes at the negatively charged nylon interface are quantified as a function of salt concentration. Single-molecule kinetics relate macroscale improvements in chromatographic peak broadening with microscale distributions of surface interaction mechanisms such as continuous-time random walks and simple adsorption-desorption. Monte Carlo simulations underpinned by the stochastic theory of chromatography are performed using kinetic data extracted from single-molecule observations. Simulations agree with experiment, revealing a decrease in peak broadening as the salt concentration increases. The results suggest that chemical modifications to membranes that decrease the probability of surface random walks could reduce peak broadening in full-scale protein separations. More broadly, this work represents a proof of concept for combining single-molecule experiments and a mechanistic theory to improve costly and time-consuming empirical methods of optimization.
Collapse
Affiliation(s)
| | | | - Hao Shen
- Department of Chemistry, Rice University, Houston, TX 77251
| | | | | | - Rashad Baiyasi
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251
| | - Wenxiao Wang
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251
| | - Fan Ye
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251
| | - Jacob T Robinson
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251
- Department of Bioengineering, Rice University, Houston, TX 77251
| | - Christy F Landes
- Department of Chemistry, Rice University, Houston, TX 77251;
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77251
- Smalley-Curl Institute, Rice University, Houston, TX 77251
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX 77251
| |
Collapse
|
12
|
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]
|
13
|
Coceancigh H, Higgins DA, Ito T. Optical Microscopic Techniques for Synthetic Polymer Characterization. Anal Chem 2018; 91:405-424. [PMID: 30350610 DOI: 10.1021/acs.analchem.8b04694] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Herman Coceancigh
- Department of Chemistry , Kansas State University , 213 CBC Building , Manhattan , Kansas 66506-0401 , United States
| | - Daniel A Higgins
- Department of Chemistry , Kansas State University , 213 CBC Building , Manhattan , Kansas 66506-0401 , United States
| | - Takashi Ito
- Department of Chemistry , Kansas State University , 213 CBC Building , Manhattan , Kansas 66506-0401 , United States
| |
Collapse
|
14
|
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.
Collapse
|
15
|
Wang W, Shen H, Moringo NA, Carrejo NC, Ye F, Robinson JT, Landes CF. Super-Temporal-Resolved Microscopy Reveals Multistep Desorption Kinetics of α-Lactalbumin from Nylon. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6697-6702. [PMID: 29763567 DOI: 10.1021/acs.langmuir.8b00686] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Insight into the mechanisms driving protein-polymer interactions is constantly improving due to advances in experimental and computational methods. In this study, we used super-temporal-resolved microscopy (STReM) to study the interfacial kinetics of a globular protein, α-lactalbumin (α-LA), adsorbing at the water-nylon 6,6 interface. The improved temporal resolution of STReM revealed that residence time distributions involve an additional step in the desorption process. Increasing the ionic strength in the bulk solution accelerated the desorption rate of α-LA, attributed to adsorption-induced conformational changes. Ensemble circular dichroism measurements were used to support a consecutive reaction mechanism. Without the improved temporal resolution of STReM, the desorption intermediate was not resolvable, highlighting both STReM's potential to uncover new kinetic mechanisms and the continuing need to push for better time and space resolution.
Collapse
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
| | - Nicholas A Moringo
- Department of Chemistry , Rice University , MS 60 , Houston , Texas 77251-1892 , United States
| | - Nicole C Carrejo
- Department of Chemistry , Rice University , MS 60 , Houston , Texas 77251-1892 , United States
| | - Fan Ye
- Department of Electrical and Computer Engineering , Rice University , MS 366 , Houston , Texas 77251-1892 , United States
| | - Jacob T Robinson
- Department of Electrical and Computer Engineering , Rice University , MS 366 , Houston , Texas 77251-1892 , United States
- Department of Bioengineering , Rice University , MS 142 , 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
| |
Collapse
|