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Geraili Daronkola H, Vila Verde A. Prevalence and mechanism of synergistic carboxylate-cation-water interactions in halophilic proteins. Biophys J 2023; 122:2577-2589. [PMID: 37179455 PMCID: PMC10323026 DOI: 10.1016/j.bpj.2023.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/02/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023] Open
Abstract
The cytoplasmic proteins of some halophilic organisms remain stable and functional at multimolar concentrations of KCl, i.e., under conditions that most mesophilic proteins cannot withstand. Their stability arises from their unusual amino acid composition. The most dramatic difference between halophilic and mesophilic proteins is that the former are rich in acidic amino acids. It has been proposed that one of the evolutionary driving forces for this difference is the occurrence of synergistic interactions between multiple acidic amino acids at the surface of the protein, the potassium cations in solution, and water. We investigate this possibility with molecular dynamics simulations, using high-quality force fields for the protein-water, protein-ion, and ion-ion interactions. We create a rigorous thermodynamic definition of interactions between acidic amino acids on proteins that can be used to distinguish between synergistic, noninteracting and interfering interactions. Our results demonstrate that synergistic interactions between neighboring acidic amino acids in halophilic proteins are frequent at multimolar KCl concentration. Synergistic interactions have an electrostatic origin, and are associated with stronger water-to-carboxylate hydrogen bonds than for acidic amino acids without synergistic interactions. Synergistic interactions are not observed in minimal systems of carboxylates, indicating that the protein environment is critical for their emergence. Our results demonstrate that synergistic interactions are neither associated with rigid amino acid orientations nor with highly structured and slow moving water networks, as had been originally proposed. Moreover, synergistic interactions can also be found in unfolded protein conformations. However, because these conformations are only a small subset of the unfolded state ensemble, synergistic interactions should contribute to the net stabilization of the folded state.
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Affiliation(s)
- Hosein Geraili Daronkola
- Max Planck Institute of Colloids and Interfaces, Department of Theory & Bio-Systems, Potsdam, Germany
| | - Ana Vila Verde
- Max Planck Institute of Colloids and Interfaces, Department of Theory & Bio-Systems, Potsdam, Germany.
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Proteins maintain hydration at high [KCl] concentration regardless of content in acidic amino acids. Biophys J 2021; 120:2746-2762. [PMID: 34087206 PMCID: PMC8390907 DOI: 10.1016/j.bpj.2021.05.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/22/2021] [Accepted: 05/19/2021] [Indexed: 11/23/2022] Open
Abstract
Proteins of halophilic organisms, which accumulate molar concentrations of KCl in their cytoplasm, have a much higher content in acidic amino acids than proteins of mesophilic organisms. It has been proposed that this excess is necessary to maintain proteins hydrated in an environment with low water activity, either via direct interactions between water and the carboxylate groups of acidic amino acids or via cooperative interactions between acidic amino acids and hydrated cations. Our simulation study of five halophilic proteins and five mesophilic counterparts does not support either possibility. The simulations use the AMBER ff14SB force field with newly optimized Lennard-Jones parameters for the interactions between carboxylate groups and potassium ions. We find that proteins with a larger fraction of acidic amino acids indeed have higher hydration levels, as measured by the concentration of water in their hydration shell and the number of water/protein hydrogen bonds. However, the hydration level of each protein is identical at low (bKCl = 0.15 mol/kg) and high (bKCl = 2 mol/kg) KCl concentrations; excess acidic amino acids are clearly not necessary to maintain proteins hydrated at high salt concentration. It has also been proposed that cooperative interactions between acidic amino acids in halophilic proteins and hydrated cations stabilize the folded protein structure and would lead to slower dynamics of the solvation shell. We find that the translational dynamics of the solvation shell is barely distinguishable between halophilic and mesophilic proteins; if such a cooperative effect exists, it does not have that entropic signature.
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Kuo TC, Huang YC, Matulis D, Chen WY. Molecular self-interactions of ribonuclease A revealed by isothermal titration calorimetry and self-interaction chromatography – Effects of anisotropy of protein surface charges. J Taiwan Inst Chem Eng 2019. [DOI: 10.1016/j.jtice.2018.12.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Fuentes D, Muñoz NM, Guo C, Polak U, Minhaj AA, Allen WJ, Gustin MC, Cressman ENK. A molecular dynamics approach towards evaluating osmotic and thermal stress in the extracellular environment. Int J Hyperthermia 2018; 35:559-567. [PMID: 30303437 DOI: 10.1080/02656736.2018.1512161] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/13/2018] [Accepted: 08/12/2018] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE A molecular dynamics approach to understanding fundamental mechanisms of combined thermal and osmotic stress induced by thermochemical ablation (TCA) is presented. METHODS Structural models of fibronectin and fibronectin bound to its integrin receptor provide idealized models for the effects of thermal and osmotic stress in the extracellular matrix. Fibronectin binding to integrin is known to facilitate cell survival. The extracellular environment produced by TCA at the lesion boundary was modelled at 37 °C and 43 °C with added sodium chloride (NaCl) concentrations (0, 40, 80, 160, and 320 mM). Atomistic simulations of solvated proteins were performed using the GROMOS96 force field and TIP3P water model. Computational results were compared with the results of viability studies of human hepatocellular carcinoma (HCC) cell lines HepG2 and Hep3B under matching thermal and osmotic experimental conditions. RESULTS Cell viability was inversely correlated with hyperthermal and hyperosmotic stresses. Added NaCl concentrations were correlated with a root mean square fluctuation increase of the fibronectin arginylglycylaspartic acid (RGD) binding domain. Computed interaction coefficients demonstrate preferential hydration of the protein model and are correlated with salt-induced strengthening of hydrophobic interactions. Under the combined hyperthermal and hyperosmotic stress conditions (43 °C and 320 mM added NaCl), the free energy change required for fibronectin binding to integrin was less favorable than that for binding under control conditions (37 °C and 0 mM added NaCl). CONCLUSION Results quantify multiple measures of structural changes as a function of temperature increase and addition of NaCl to the solution. Correlations between cell viability and stability measures suggest that protein aggregates, non-functional proteins, and less favorable cell attachment conditions have a role in TCA-induced cell stress.
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Affiliation(s)
- David Fuentes
- a Department of Imaging Physics , M. D. Anderson Cancer Center, The University of Texas , Houston , TX , USA
| | - Nina M Muñoz
- b Department of Interventional Radiology , M. D. Anderson Cancer Center, The University of Texas, Houston , TX , USA
| | - Chunxiao Guo
- b Department of Interventional Radiology , M. D. Anderson Cancer Center, The University of Texas, Houston , TX , USA
| | - Urzsula Polak
- b Department of Interventional Radiology , M. D. Anderson Cancer Center, The University of Texas, Houston , TX , USA
| | - Adeeb A Minhaj
- b Department of Interventional Radiology , M. D. Anderson Cancer Center, The University of Texas, Houston , TX , USA
| | - William J Allen
- c Texas Advanced Computing Center , The University of Texas at Austin , Austin , TX , USA
| | - Michael C Gustin
- d Department of Biosciences , Rice University , Houston , TX , USA
| | - Erik N K Cressman
- b Department of Interventional Radiology , M. D. Anderson Cancer Center, The University of Texas, Houston , TX , USA
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5
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AUC measurements of diffusion coefficients of monoclonal antibodies in the presence of human serum proteins. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 47:709-722. [DOI: 10.1007/s00249-018-1319-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 05/07/2018] [Accepted: 07/04/2018] [Indexed: 12/21/2022]
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Platten F, Hansen J, Wagner D, Egelhaaf SU. Second Virial Coefficient As Determined from Protein Phase Behavior. J Phys Chem Lett 2016; 7:4008-4014. [PMID: 27662500 DOI: 10.1021/acs.jpclett.6b01714] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We quantitatively link the macroscopic phase behavior of protein solutions to protein-protein interactions based on a coarse-grained colloidal approach. We exploit the extended law of corresponding states and apply the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory in order to infer the second virial coefficient b2, an integral measure of the interaction potential, from the phase behavior, namely, cloud-point temperature (CPT) measurements under conditions favoring protein crystallization. This determination of b2 yields values that quantitatively agree with the results of static light scattering (SLS) experiments. The strength of the attractions is quantified in terms of an effective Hamaker constant, which accounts for van der Waals attractions as well as non-DLVO forces, such as hydration and hydrophobic interactions. Our approach based on simple lab experiments to determine the CPT in combination with the DLVO theory is expected to facilitate further biophysical research on protein-protein interactions in complex solution environments.
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Affiliation(s)
- Florian Platten
- Condensed Matter Physics Laboratory, Heinrich Heine University , 40225 Düsseldorf, Germany
| | - Jan Hansen
- Condensed Matter Physics Laboratory, Heinrich Heine University , 40225 Düsseldorf, Germany
| | - Dana Wagner
- Condensed Matter Physics Laboratory, Heinrich Heine University , 40225 Düsseldorf, Germany
| | - Stefan U Egelhaaf
- Condensed Matter Physics Laboratory, Heinrich Heine University , 40225 Düsseldorf, Germany
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Yano YF, Kobayashi Y, Ina T, Nitta K, Uruga T. Hofmeister Anion Effects on Protein Adsorption at an Air-Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:9892-9898. [PMID: 27575543 DOI: 10.1021/acs.langmuir.6b02352] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Hofmeister anion effects on adsorption kinetics of the positively charged lysozyme (pH < pI) at an air-water interface were studied by surface tension measurements and time-resolved X-ray reflectometry. In the salt-free solution, the protein adsorption rate increases with decreasing the net positive charge of lysozyme. When salt ions are dissolved in water, the protein adsorption rate drastically increases, and the rate is following an inverse Hoffmeister series (Br(-) > Cl(-) > F(-)). This is the result of the strongly polarized halide anion Br(-) being attracted to the adsorbed protein layer due to strong interaction with local electric field, while weakly polarized anion F(-) having no ability to penetrate the protein layer. In X-ray reflection studies, we observed that the lysozyme molecules initially adsorbed on the air-water interface have a flat unfolded structure as previously reported in the salt-free solution. In contrast, in the concentrated salt solutions, the lysozyme molecules begin to refold during adsorption. This protein refolding as a result of protein-protein rearrangements may be a precursor phenomenon of crystallization. The refolding is most significant for Cl(-), which is a good crystallization agent, whereas it is less observed for the strongly hydrated F(-). It is widely known in the bulk state that kosmotropic anions tend to precipitate proteins but at the same time stabilize proteins against denaturing. On the other hand, at the air-water interface where adsorbed proteins usually unfold, we observed chaotropic anions strongly bound to proteins that reduce electrostatic repulsion between protein molecules, and subsequently they induce protein refolding whereas the kosmotropic anions do not.
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Affiliation(s)
- Yohko F Yano
- Department of Physics, Kindai University , 3-4-1 Kowakae, Higashiosaka City, Osaka 577-8502, Japan
| | - Yuki Kobayashi
- Department of Physics, Kindai University , 3-4-1 Kowakae, Higashiosaka City, Osaka 577-8502, Japan
| | - Toshiaki Ina
- Japan Synchrotron Radiation Research Institute , 1-1-1 Kouto, Sayo-cyo, Sayo-gun, Hyogo 679-5198, Japan
| | - Kiyofumi Nitta
- Japan Synchrotron Radiation Research Institute , 1-1-1 Kouto, Sayo-cyo, Sayo-gun, Hyogo 679-5198, Japan
| | - Tomoya Uruga
- Japan Synchrotron Radiation Research Institute , 1-1-1 Kouto, Sayo-cyo, Sayo-gun, Hyogo 679-5198, Japan
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Self-Interaction Chromatography of mAbs: Accurate Measurement of Dead Volumes. Pharm Res 2015; 32:3975-85. [PMID: 26268546 PMCID: PMC4628098 DOI: 10.1007/s11095-015-1758-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/14/2015] [Indexed: 10/31/2022]
Abstract
PURPOSE Measurement of the second virial coefficient B22 for proteins using self-interaction chromatography (SIC) is becoming an increasingly important technique for studying their solution behaviour. In common with all physicochemical chromatographic methods, measuring the dead volume of the SIC packed column is crucial for accurate retention data; this paper examines best practise for dead volume determination. METHOD SIC type experiments using catalase, BSA, lysozyme and a mAb as model systems are reported, as well as a number of dead column measurements. RESULTS It was observed that lysozyme and mAb interacted specifically with Toyopearl AF-Formyl dead columns depending upon pH and [NaCl], invalidating their dead volume usage. Toyopearl AF-Amino packed dead columns showed no such problems and acted as suitable dead columns without any solution condition dependency. Dead volume determinations using dextran MW standards with protein immobilised SIC columns provided dead volume estimates close to those obtained using Toyopearl AF-Amino dead columns. CONCLUSION It is concluded that specific interactions between proteins, including mAbs, and select SIC support phases can compromise the use of some standard approaches for estimating the dead volume of SIC columns. Two other methods were shown to provide good estimates for the dead volume.
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Pethica BA. Misuse of thermodynamics in the interpretation of isothermal titration calorimetry data for ligand binding to proteins. Anal Biochem 2015; 472:21-9. [DOI: 10.1016/j.ab.2014.11.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 11/07/2014] [Accepted: 11/12/2014] [Indexed: 10/24/2022]
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Johnson DH, Wilson WW, DeLucas LJ. Protein solubilization: a novel approach. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 971:99-106. [PMID: 25270058 DOI: 10.1016/j.jchromb.2014.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2013] [Revised: 08/27/2014] [Accepted: 09/04/2014] [Indexed: 11/25/2022]
Abstract
Formulation development presents significant challenges with respect to protein therapeutics. One component of these challenges is to attain high protein solubility (>50mg/ml for immunoglobulins) with minimal aggregation. Protein-protein interactions contribute to aggregation and the integral sum of these interactions can be quantified by a thermodynamic parameter known as the osmotic second virial coefficient (B-value). The method presented here utilizes high-throughput measurement of B-values to identify the influence of additives on protein-protein interactions. The experiment design uses three tiers of screens to arrive at final solution conditions that improve protein solubility. The first screen identifies individual additives that reduce protein interactions. A second set of B-values are then measured for different combinations of these additives via an incomplete factorial screen. Results from the incomplete factorial screen are used to train an artificial neural network (ANN). The "trained" ANN enables predictions of B-values for more than 4000 formulations that include additive combinations not previously experimentally measured. Validation steps are incorporated throughout the screening process to ensure that (1) the protein's thermal and aggregation stability characteristics are not reduced and (2) the artificial neural network predictive model is accurate. The ability of this approach to reduce aggregation and increase solubility is demonstrated using an IgG protein supplied by Minerva Biotechnologies, Inc.
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Affiliation(s)
- David H Johnson
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - W William Wilson
- Department of Chemistry, Mississippi State University, Starkville, MS, USA
| | - Lawrence J DeLucas
- Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, 1530 Third Avenue South, Birmingham, AL 35294, USA.
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Wilson WW, Delucas LJ. Applications of the second virial coefficient: protein crystallization and solubility. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2014; 70:543-54. [PMID: 24817708 PMCID: PMC4014317 DOI: 10.1107/s2053230x1400867x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 04/16/2014] [Indexed: 11/10/2022]
Abstract
This article begins by highlighting some of the ground-based studies emanating from NASA's Microgravity Protein Crystal Growth (PCG) program. This is followed by a more detailed discussion of the history of and the progress made in one of the NASA-funded PCG investigations involving the use of measured second virial coefficients (B values) as a diagnostic indicator of solution conditions conducive to protein crystallization. A second application of measured B values involves the determination of solution conditions that improve or maximize the solubility of aqueous and membrane proteins. These two important applications have led to several technological improvements that simplify the experimental expertise required, enable the measurement of membrane proteins and improve the diagnostic capability and measurement throughput.
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Affiliation(s)
| | - Lawrence J Delucas
- Center for Structural Biology, University of Alabama at Birmingham, 1720 Second Avenue South, Birmingham, AL 35294, USA
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McBride DW, Rodgers V. Interpretation of negative second virial coefficients from non-attractive protein solution osmotic pressure data: An alternate perspective. Biophys Chem 2013; 184:79-86. [DOI: 10.1016/j.bpc.2013.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 09/17/2013] [Accepted: 09/23/2013] [Indexed: 10/26/2022]
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Binabaji E, Rao S, Zydney AL. Improved method for evaluating the dead volume and protein-protein interactions by self-interaction chromatography. Anal Chem 2013; 85:9101-6. [PMID: 23971517 DOI: 10.1021/ac4017242] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Self-interaction chromatography (SIC) is a well-established method for studying protein-protein interactions. The second virial coefficient in SIC is evaluated directly from the measured retention coefficient for the protein using a column packed with resin on which the same protein has been immobilized on the pore surface. One of the challenges in determining the retention coefficient is the evaluation of the dead volume, which is the retention volume that would be measured for a noninteracting solute with the same effective size as the protein of interest. Previous studies of SIC have used a "dead column" packed with the same resin but without the immobilized protein to evaluate the dead volume, but this creates several experimental and theoretical challenges. We have developed a new approach using a dextran standard with effective size equal to that of the protein (as determined by size exclusion chromatography). The second virial coefficient was evaluated for a monoclonal antibody over a range of buffer conditions using this new approach. The data were in good agreement with independent measurements obtained by membrane osmometry under conditions dominated by repulsive interactions. The simplicity and accuracy of this method should facilitate the use of self-interaction chromatography for quantifying protein-protein interactions.
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Affiliation(s)
- Elaheh Binabaji
- Department of Chemical Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
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Thakkar SV, Allegre KM, Joshi SB, Volkin DB, Middaugh CR. An Application of Ultraviolet Spectroscopy to Study Interactions in Proteins Solutions at High Concentrations. J Pharm Sci 2012; 101:3051-61. [DOI: 10.1002/jps.23188] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 04/12/2012] [Accepted: 04/24/2012] [Indexed: 11/11/2022]
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Siderius DW, Krekelberg WP, Roberts CJ, Shen VK. Osmotic virial coefficients for model protein and colloidal solutions: Importance of ensemble constraints in the analysis of light scattering data. J Chem Phys 2012; 136:175102. [DOI: 10.1063/1.4709613] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sule SV, Cheung JK, Antochshuk V, Bhalla AS, Narasimhan C, Blaisdell S, Shameem M, Tessier PM. Solution pH that minimizes self-association of three monoclonal antibodies is strongly dependent on ionic strength. Mol Pharm 2012; 9:744-51. [PMID: 22221144 DOI: 10.1021/mp200448j] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Monoclonal antibodies display highly variable solution properties such as solubility and viscosity at elevated concentrations (>50 mg/mL), which complicates antibody formulation and delivery. To understand this complex behavior, it is critical to measure the underlying protein self-interactions that govern the solution properties of antibody suspensions. We have evaluated the pH-dependent self-association behavior of three monoclonal antibodies using self-interaction chromatography for a range of pH values commonly used in antibody formulations (pH 4.4-6). At low ionic strength (<25 mM), we find that each antibody is more associative at near-neutral pH (pH 6) than at low pH (pH 4.4). At high ionic strength (>100 mM), we observe the opposite pH-dependent pattern of antibody self-association. Importantly, this inversion in self-association behavior is not unique to multidomain antibodies, as similar pH-dependent behavior is observed for some small globular proteins (e.g., ribonuclease A and α-chymotrypsinogen). We also find that the opalescence of concentrated antibody solutions (90 mg/mL) is minimized at low ionic strength at pH 4.4 and high ionic strength at pH 6, in agreement with the self-interaction measurements conducted at low antibody concentrations (5 mg/mL). Our results highlight the complexity of antibody self-association and emphasize the need for systematic approaches to optimize the solution properties of concentrated antibody formulations.
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Affiliation(s)
- Shantanu V Sule
- Center for Biotechnology & Interdisciplinary Studies, Department of Chemical & Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
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Blanco MA, Sahin E, Li Y, Roberts CJ. Reexamining protein-protein and protein-solvent interactions from Kirkwood-Buff analysis of light scattering in multi-component solutions. J Chem Phys 2011; 134:225103. [PMID: 21682538 DOI: 10.1063/1.3596726] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The classic analysis of Rayleigh light scattering (LS) is re-examined for multi-component protein solutions, within the context of Kirkwood-Buff (KB) theory as well as a more generalized canonical treatment. Significant differences arise when traditional treatments that approximate constant pressure and neglect concentration fluctuations in one or more (co)solvent/co-solute species are compared with more rigorous treatments at constant volume and with all species free to fluctuate. For dilute solutions, it is shown that LS can be used to rigorously and unambiguously obtain values for the osmotic second virial coefficient (B(22)), in contrast with recent arguments regarding protein interactions deduced from LS experiments. For more concentrated solutions, it is shown that conventional analysis over(under)-estimates the magnitude of B(22) for significantly repulsive(attractive) conditions, and that protein-protein KB integrals (G(22)) are the more relevant quantity obtainable from LS. Published data for α-chymotrypsinogen A and a series of monoclonal antibodies at different pH and salt concentrations are re-analyzed using traditional and new treatments. The results illustrate that while traditional analysis may be sufficient if one is interested in only the sign of B(22) or G(22), the quantitative values can be significantly in error. A simple approach is illustrated for determining whether protein concentration (c(2)) is sufficiently dilute for B(22) to apply, and for correcting B(22) values from traditional LS regression at higher c(2) values. The apparent molecular weight M(2, app) obtained from LS is shown to generally not be equal to the true molecular weight, with the differences arising from a combination of protein-solute and protein-cosolute interactions that may, in principle, also be determined from LS.
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Affiliation(s)
- Marco A Blanco
- Department of Chemical Engineering and Center for Molecular and Engineering Thermodynamics, University of Delaware, Newark, Delaware 19716, USA
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Refolding of proteins from inclusion bodies: rational design and recipes. Appl Microbiol Biotechnol 2011; 92:241-51. [DOI: 10.1007/s00253-011-3513-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 07/18/2011] [Accepted: 07/24/2011] [Indexed: 01/31/2023]
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Sokolová L, Williamson H, Sýkora J, Hof M, Gray HB, Brutschy B, Vlcek A. Mass spectrometric characterization of oligomers in Pseudomonas aeruginosa azurin solutions. J Phys Chem B 2011; 115:4790-800. [PMID: 21452827 DOI: 10.1021/jp110460k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have employed laser-induced liquid bead ion desorption mass spectroscopy (LILBID MS) to study the solution behavior of Pseudomonas aeruginosa azurin as well as two mutants and corresponding Re-labeled derivatives containing a Re(CO)(3)(4,7-dimethyl-1,10-phenanthroline)(+) chromophore appended to a surface histidine. LILBID spectra show broad oligomer distributions whose particular patterns depend on the solution composition (pure H(2)O, 20-30 mM NaCl, 20 and 50 mM NaP(i) or NH(4)P(i) at pH = 7). The distribution maximum shifts to smaller oligomers upon decreasing the azurin concentration and increasing the buffer concentration. Oligomerization is less extensive for native azurin than its mutants. The oligomerization propensities of unlabeled and Re-labeled proteins are generally comparable, and only Re126 shows some preference for the dimer that persists even in highly diluted solutions. Peak shifts to higher masses and broadening in 20-50 mM NaP(i) confirm strong azurin association with buffer ions and solvation. We have found that LILBID MS reveals the solution behavior of weakly bound nonspecific protein oligomers, clearly distinguishing individual components of the oligomer distribution. Independently, average data on oligomerization and the dependence on solution composition were obtained by time-resolved anisotropy of the Re-label photoluminescence that confirmed relatively long rotation correlation times, 6-30 ns, depending on Re-azurin and solution composition. Labeling proteins with Re-chromophores that have long-lived phosphorescence extends the time scale of anisotropy measurements to hundreds of nanoseconds, thereby opening the way for investigations of large oligomers with long rotation times.
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Affiliation(s)
- Lucie Sokolová
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt am Main, Germany
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Saluja A, Fesinmeyer RM, Hogan S, Brems DN, Gokarn YR. Diffusion and sedimentation interaction parameters for measuring the second virial coefficient and their utility as predictors of protein aggregation. Biophys J 2011; 99:2657-65. [PMID: 20959107 DOI: 10.1016/j.bpj.2010.08.020] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/05/2010] [Accepted: 08/10/2010] [Indexed: 12/28/2022] Open
Abstract
The concentration-dependence of the diffusion and sedimentation coefficients (k(D) and k(s), respectively) of a protein can be used to determine the second virial coefficient (B₂), a parameter valuable in predicting protein-protein interactions. Accurate measurement of B₂ under physiologically and pharmaceutically relevant conditions, however, requires independent measurement of k(D) and k(s) via orthogonal techniques. We demonstrate this by utilizing sedimentation velocity (SV) and dynamic light scattering (DLS) to analyze solutions of hen-egg white lysozyme (HEWL) and a monoclonal antibody (mAb1) in different salt solutions. The accuracy of the SV-DLS method was established by comparing measured and literature B₂ values for HEWL. In contrast to the assumptions necessary for determining k(D) and k(s) via SV alone, k(D) and ks were of comparable magnitudes, and solution conditions were noted for both HEWL and mAb1 under which 1), k(D) and k(s) assumed opposite signs; and 2), k(D) ≥k(s). Further, we demonstrate the utility of k(D) and k(s) as qualitative predictors of protein aggregation through agitation and accelerated stability studies. Aggregation of mAb1 correlated well with B₂, k(D), and k(s), thus establishing the potential for k(D) to serve as a high-throughput predictor of protein aggregation.
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Affiliation(s)
- Atul Saluja
- Process and Product Development, Amgen, Seattle, Washington
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Abstract
A novel miniaturized system has been developed for measuring protein-protein interactions in solution with high efficiency and speed, and minimal use of protein. A chromatographic monolith synthesized in a capillary is used in the method to make interaction measurements by self-interaction chromatography (SIC) in a manner that, compared to column methods, is more efficient as well as more readily practicable even if only small amounts of protein are available. The microfluidic monolith requires much less protein for both column synthesis and the chromatographic measurements than a conventional SIC system, and in addition offers improved mass transfer and hence higher chromatographic efficiency than for previous SIC miniaturization systems. Protein self-interactions for catalase as a model protein, quantified by measurement of second virial coefficients, B(22), were determined by SIC and follow trends that are consistent with previously reported values. Different column derivatization conditions were studied in order to optimize the chromatographic behavior of the microfluidic system for SIC measurements. Chromatographic sensitivity can be further increased by using different column synthesis conditions.
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Affiliation(s)
- Cristina Martin
- Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA
| | - Abraham M. Lenhoff
- Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA
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Li Y, Ogunnaike BA, Roberts CJ. Multi-variate approach to global protein aggregation behavior and kinetics: Effects of pH, NaCl, and temperature for α-chymotrypsinogen A. J Pharm Sci 2010; 99:645-62. [DOI: 10.1002/jps.21869] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Bengali AN, Tessier PM. Biospecific protein immobilization for rapid analysis of weak protein interactions using self-interaction nanoparticle spectroscopy. Biotechnol Bioeng 2009; 104:240-50. [DOI: 10.1002/bit.22392] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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26
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Tesarík R, Sedlácek V, Plocková J, Wimmerová M, Turánek J, Kucera I. Heterologous expression and molecular characterization of the NAD(P)H:acceptor oxidoreductase (FerB) of Paracoccus denitrificans. Protein Expr Purif 2009; 68:233-8. [PMID: 19651218 DOI: 10.1016/j.pep.2009.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 07/26/2009] [Accepted: 07/28/2009] [Indexed: 11/15/2022]
Abstract
FerB is a flavoenzyme capable of reducing quinones, ferric complexes and chromate. Its expression in Escherichia coli as a hexahistidine fusion resulted in a functional product only when the tag was placed on the C-terminus. The molecular mass values estimated by gel permeation chromatography were compatible with the existence of either dimer or trimer, whereas the light scattering data, together with cross-linking experiments that yielded exclusively monomer and dimer bands on dodecyl sulfate-polyacrylamide gels, strongly supported a dimeric nature of both native and tagged form of FerB. These two proteins also exhibited almost identical secondary structure as judged by Fourier transform infra red spectrometry. The presence of tag, however, shifted the temperature of thermal inactivation as well as the thermal denaturation curve towards lower temperatures. Despite somewhat lower thermal stability, the fusion protein is considered a better candidate for crystallization than the wild-type one due to a more negative value of its second optical viral coefficient.
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Affiliation(s)
- Radek Tesarík
- Department of Vaccinology and Immunotherapy, Veterinary Research Institute, Hudcova 70, CZ-62100 Brno, Czech Republic
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27
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Deshpande KS, Ahamed T, ter Horst JH, Jansens PJ, van der Wielen LAM, Ottens M. The use of self-interaction chromatography in stable formulation and crystallization of proteins. Biotechnol J 2009; 4:1266-77. [DOI: 10.1002/biot.200800226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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28
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Le Brun V, Friess W, Schultz-Fademrecht T, Muehlau S, Garidel P. Lysozyme-lysozyme self-interactions as assessed by the osmotic second virial coefficient: Impact for physical protein stabilization. Biotechnol J 2009; 4:1305-19. [DOI: 10.1002/biot.200800274] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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Demeule B, Palais C, Machaidze G, Gurny R, Arvinte T. New methods allowing the detection of protein aggregates: a case study on trastuzumab. MAbs 2009; 1:142-50. [PMID: 20061815 DOI: 10.4161/mabs.1.2.7632] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Aggregation compromises the safety and efficacy of therapeutic proteins. According to the manufacturer, the therapeutic immunoglobulin trastuzumab (Herceptin) should be diluted in 0.9% sodium chloride before administration. Dilution in 5% dextrose solutions is prohibited. The reason for the interdiction is not mentioned in the Food and Drug Administration (FDA) documentation, but the European Medicines Agency (EMEA) Summary of Product Characteristics states that dilution of trastuzumab in dextrose solutions results in protein aggregation. In this paper, asymmetrical flow field-flow fractionation (FFF), fluorescence spectroscopy, fluorescence microscopy and transmission electron microscopy (TEM) have been used to characterize trastuzumab samples diluted in 0.9% sodium chloride, a stable infusion solution, as well as in 5% dextrose (a solution prone to aggregation). When trastuzumab samples were injected in the FFF channel using a standard separation method, no difference could be seen between trastuzumab diluted in sodium chloride and trastuzumab diluted in dextrose. However, during FFF measurements made with appropriate protocols, aggregates were detected in 5% dextrose. The parameters enabling the detection of reversible trastuzumab aggregates are described. Aggregates could also be documented by fluorescence microscopy and TEM. Fluorescence spectroscopy data were indicative of conformational changes consistent with increased aggregation and adsorption to surfaces. The analytical methods presented in this study were able to detect and characterize trastuzumab aggregates.
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Affiliation(s)
- Barthélemy Demeule
- Department of Pharmaceutics and Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
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30
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Self-interaction of native and denatured lysozyme in the presence of osmolytes, l-arginine and guanidine hydrochloride. Biochem Eng J 2009. [DOI: 10.1016/j.bej.2008.10.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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31
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Dumetz AC, Lewus RA, Lenhoff AM, Kaler EW. Effects of ammonium sulfate and sodium chloride concentration on PEG/protein liquid-liquid phase separation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:10345-10351. [PMID: 18702478 DOI: 10.1021/la801180n] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
When added to protein solutions, poly(ethylene glycol) (PEG) creates an effective attraction between protein molecules due to depletion forces. This effect has been widely used to crystallize proteins, and PEG is among the most successful crystallization agents in current use. However, PEG is almost always used in combination with a salt at either low or relatively high concentrations. Here the effects of sodium chloride and ammonium sulfate concentration on PEG 8000/ovalbumin liquid-liquid (L-L) phase separation are investigated. At low salt the L-L phase separation occurs at decreasing protein concentration with increasing salt concentration, presumably due to repulsive electrostatic interactions between proteins. At high salt concentration, the behavior depends on the nature of the salt. Sodium chloride has little effect on the L-L phase separation, but ammonium sulfate decreases the protein concentration at which the L-L phase separation occurs. This trend is attributed to the effects of critical fluctuations on depletion forces. The implications of these results for designing solution conditions optimal for protein crystallization are discussed.
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Affiliation(s)
- André C Dumetz
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, DE 19716, USA
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32
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Lou C, Shindel M, Graham L, Wang SW. Molecular self-assembly of solid-supported protein crystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:8111-8118. [PMID: 18605704 DOI: 10.1021/la8004008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Highly ordered protein arrays have been proposed as a means for templating the organization of nanomaterials. Toward this end, we investigate the ability of the protein streptavidin to self-assemble into various configurations on solid-supported phospholipids. We identify two genetic variants of streptavidin (comprising amino acids 14-136 and 13-139) and examine their molecular organization at the liquid-solid interface. Our results demonstrate that the structural differences between these two protein variants affect both crystalline lattice and domain morphology. In general, these results for the liquid-solid interface are similar and consistent with those at the air-water interface with a few notable differences. Analogous to crystallization at the air-water interface, both forms of streptavidin yield H-like domains with lattice parameters that have C222 symmetry at pH 7. At pH 4, the native, truncated form of streptavidin yields needle-like domains consisting of molecules arranged in P1 symmetry. Unlike crystalline domains grown at the air-water interface, however, the lattice parameters of this P1 crystal are unique and have not yet been reported. The presence of a solid substrate does not appear to dramatically alter streptavidin's two-dimensional crystallization behavior, suggesting that local intermolecular interactions between proteins are more significant than interactions between the interface and protein. Our results also demonstrate that screening the electrostatic repulsion between protein molecules by modulating ionic strength will increase growth rate while decreasing crystalline domain size and macroscopic defects. Finally, we show that these domains are indeed functional by attaching biotinylated gold nanoparticles to the crystals. The ability to modulate molecular configuration, crystalline defects, and domain size on a functional array supports the potential application of this system toward materials assembly.
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Affiliation(s)
- Chengfei Lou
- Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697-2575, USA
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33
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Su R, Qi W, He Z, Zhang Y, Jin F. Multilevel structural nature and interactions of bovine serum albumin during heat-induced aggregation process. Food Hydrocoll 2008. [DOI: 10.1016/j.foodhyd.2007.05.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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34
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Tessier PM, Jinkoji J, Cheng YC, Prentice JL, Lenhoff AM. Self-Interaction Nanoparticle Spectroscopy: A Nanoparticle-Based Protein Interaction Assay. J Am Chem Soc 2008; 130:3106-12. [DOI: 10.1021/ja077624q] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter M. Tessier
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716
| | - Jun Jinkoji
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716
| | - Yu-Chia Cheng
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716
| | - Jessica L. Prentice
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716
| | - Abraham M. Lenhoff
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716
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35
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Dumetz AC, Snellinger-O'brien AM, Kaler EW, Lenhoff AM. Patterns of protein protein interactions in salt solutions and implications for protein crystallization. Protein Sci 2007; 16:1867-77. [PMID: 17766383 PMCID: PMC2206983 DOI: 10.1110/ps.072957907] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 06/19/2007] [Accepted: 06/20/2007] [Indexed: 10/22/2022]
Abstract
The second osmotic virial coefficients of seven proteins-ovalbumin, ribonuclease A, bovine serum albumin, alpha-lactalbumin, myoglobin, cytochrome c, and catalase-were measured in salt solutions. Comparison of the interaction trends in terms of the dimensionless second virial coefficient b(2) shows that, at low salt concentrations, protein-protein interactions can be either attractive or repulsive, possibly due to the anisotropy of the protein charge distribution. At high salt concentrations, the behavior depends on the salt: In sodium chloride, protein interactions generally show little salt dependence up to very high salt concentrations, whereas in ammonium sulfate, proteins show a sharp drop in b(2) with increasing salt concentration beyond a particular threshold. The experimental phase behavior of the proteins corroborates these observations in that precipitation always follows the drop in b(2). When the proteins crystallize, they do so at slightly lower salt concentrations than seen for precipitation. The b(2) measurements were extended to other salts for ovalbumin and catalase. The trends follow the Hofmeister series, and the effect of the salt can be interpreted as a water-mediated effect between the protein and salt molecules. The b(2) trends quantify protein-protein interactions and provide some understanding of the corresponding phase behavior. The results explain both why ammonium sulfate is among the best crystallization agents, as well as some of the difficulties that can be encountered in protein crystallization.
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Affiliation(s)
- André C Dumetz
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716, USA
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36
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Gitlin I, Carbeck JD, Whitesides GM. Why are proteins charged? Networks of charge-charge interactions in proteins measured by charge ladders and capillary electrophoresis. Angew Chem Int Ed Engl 2007; 45:3022-60. [PMID: 16619322 DOI: 10.1002/anie.200502530] [Citation(s) in RCA: 196] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Almost all proteins contain charged amino acids. While the function in catalysis or binding of individual charges in the active site can often be identified, it is less clear how to assign function to charges beyond this region. Are they necessary for solubility? For reasons other than solubility? Can manipulating these charges change the properties of proteins? A combination of capillary electrophoresis (CE) and protein charge ladders makes it possible to study the roles of charged residues on the surface of proteins outside the active site. This method involves chemical modification of those residues to generate a large number of derivatives of the protein that differ in charge. CE separates those derivatives into groups with the same number of modified charged groups. By studying the influence of charge on the properties of proteins using charge ladders, it is possible to estimate the net charge and hydrodynamic radius and to infer the role of charged residues in ligand binding and protein folding.
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Affiliation(s)
- Irina Gitlin
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138, USA
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37
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Ghosh T, Kalra A, Garde S. On the salt-induced stabilization of pair and many-body hydrophobic interactions. J Phys Chem B 2007; 109:642-51. [PMID: 16851057 DOI: 10.1021/jp0475638] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Salting-out of hydrophobic solutes in aqueous salt solutions and their relevance to salt effects on biophysical phenomena are now well appreciated. Although salt effects on hydrophobic transfer have been well studied, to our knowledge, no quantitative molecular simulation study of salt-induced strengthening of hydrophobic interactions has yet been reported. Here we present quantitative characterization of salt-induced strengthening of hydrophobic interactions at the molecular and nanoscopic length scales through molecular dynamics simulations. Specifically, we quantify the effect of NaCl on the potential of mean force between molecular hydrophobic solutes (methanes) and on conformational equilibria of a 25-mer hydrophobic polymer that efficiently samples ensembles of compact and extended states in water. In both cases, we observe relative stabilization of compact conformations that is accompanied by a clear depletion of salt density (preferential exclusion) and a slight enhancement of water density (preferential hydration) in the solute vicinity. We show that the structural details of salt exclusion can be related to the salt-induced free energy changes using preferential interaction coefficients. We also test the applicability of surface-area-based models to describe the salt-induced free energy changes. These models provide a useful empirical description that can be used to predict the effects of salt on conformational equilibria of hydrophobic solutes. However, we find that the effective increase in the surface tension of the solute-aqueous solution interface depends on the type and concentration of salt as well as the length-scale (i.e., molecular vs nanoscopic) of the conformational change. These calculations underscore the utility of simulation studies to connect quantitatively structural details at the molecular level (described by preferential hydration/exclusion) to macroscopic solvation thermodynamics. The hydrophobic polymer also provides a useful model for studies of effect of thermodynamic variables (P, T, salt/additives) on many-body hydrophobic interactions at nanometer length scales.
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Affiliation(s)
- Tuhin Ghosh
- The Howard P. Isermann Department of Chemical & Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
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38
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To BCS, Lenhoff AM. Hydrophobic interaction chromatography of proteins. J Chromatogr A 2007; 1141:235-43. [PMID: 17207494 DOI: 10.1016/j.chroma.2006.12.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 12/02/2006] [Accepted: 12/05/2006] [Indexed: 11/21/2022]
Abstract
A general thermodynamic relation was derived to correlate protein solubility to retention in hydrophobic interaction chromatography (HIC). This relation is built on a thermodynamic formulation presented previously by Melander, Horváth and co-workers in the context of the solvophobic theory, but the final result is independent of this model framework. The relation reflects an increase in protein retention in HIC under conditions that promote precipitation or crystallization, consistent with early descriptions of HIC. To examine the contribution of protein solubility to retention in HIC, isocratic elution experiments were performed with four different commercially available agarose media and four model proteins (ribonuclease A (RNA), lysozyme (LYS), myoglobin (MYO), and ovalbumin (OVA)). A wide variety of retention trends were observed as a function of protein, adsorbent type, salt type and concentration, and pH. In general, however, the results show that solubility, or its surrogate, the second osmotic virial coefficient, which reflects solution thermodynamic properties, correlates well with HIC retention in many cases; this includes correctly predicting reverse Hofmeister effects, which cannot be explained by retention models based on the solvophobic theory and preferential interaction theory. However, solution properties could not explain retention behavior under some conditions. In those cases, effects such as protein-surface interactions or conformational change could be important determinants of protein adsorption.
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Affiliation(s)
- Brian C S To
- Merck Research Laboratories, Sumneytown Pike, West Point, PA 19486, USA
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39
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Berger BW, Gendron CM, Lenhoff AM, Kaler EW. Effects of additives on surfactant phase behavior relevant to bacteriorhodopsin crystallization. Protein Sci 2006; 15:2682-96. [PMID: 17088325 PMCID: PMC2242436 DOI: 10.1110/ps.062370506] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The interactions leading to crystallization of the integral membrane protein bacteriorhodopsin solubilized in n-octyl-beta-D-glucoside were investigated. Osmotic second virial coefficients (B(22)) were measured by self-interaction chromatography using a wide range of additives and precipitants, including polyethylene glycol (PEG) and heptane-1,2,3-triol (HT). In all cases, attractive protein-detergent complex (PDC) interactions were observed near the surfactant cloud point temperature, and there is a correlation between the surfactant cloud point temperatures and PDC B(22) values. Light scattering, isothermal titration calorimetry, and tensiometry reveal that although the underlying reasons for the patterns of interaction may be different for various combinations of precipitants and additives, surfactant phase behavior plays an important role in promoting crystallization. In most cases, solution conditions that led to crystallization fell within a similar range of slightly negative B(22) values, suggesting that weakly attractive interactions are important as they are for soluble proteins. However, the sensitivity of the cloud point temperatures and resultant coexistence curves varied significantly as a function of precipitant type, which suggests that different types of forces are involved in driving phase separation depending on the precipitant used.
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Affiliation(s)
- Bryan W Berger
- Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716, USA.
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40
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Demeule B, Lawrence MJ, Drake AF, Gurny R, Arvinte T. Characterization of protein aggregation: the case of a therapeutic immunoglobulin. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1774:146-53. [PMID: 17142116 DOI: 10.1016/j.bbapap.2006.10.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 10/12/2006] [Indexed: 11/19/2022]
Abstract
In this paper, a therapeutic immunoglobulin (Antibody A) has been characterized in two solutions: (1) 0.1% acetic acid containing 50 mM magnesium chloride, a solution in which the immunoglobulin is stable, and (2) 10 mM sodium phosphate buffer pH approximately 7. The protein solutions were characterized by microscopy, asymmetrical flow field-flow fractionation (FFF), light scattering, circular dichroism, fluorescence and fluorescence lifetime spectroscopy. The results show that Antibody A dissolved in 0.1% acetic acid containing 50 mM magnesium chloride exists as 88% monomer, 2% low molecular weight aggregates and 10% high molecular weight aggregates (>1 million Dalton). In phosphate buffer, Antibody A formed micrometre-sized aggregates that were best characterized by fluorescence microscopy. The aggregation of Antibody A in phosphate buffer was shown to be concomitant with conformational changes in amino acid residue side chains. The aggregates formed in phosphate buffer were easily disrupted during FFF analysis, indicating that they are formed by weak interactions. The combination of microscopy, asymmetrical flow field-flow fractionation (FFF) and spectroscopy allowed a reliable assessment of protein self association and aggregation.
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Affiliation(s)
- Barthélemy Demeule
- Department of Pharmaceutics and Biopharmaceutics, School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland
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41
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Saluja A, Badkar AV, Zeng DL, Nema S, Kalonia DS. Application of high‐frequency rheology measurements for analyzing protein–protein interactions in high protein concentration solutions using a model monoclonal antibody (IgG2). J Pharm Sci 2006; 95:1967-83. [PMID: 16847932 DOI: 10.1002/jps.20663] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The purpose of this work was to explore the utilization of high-frequency rheology analysis for assessing protein-protein interactions in high protein concentration solutions. Rheology analysis of a model monoclonal immunoglobulin G2 solutions was conducted on indigenously developed ultrasonic shear rheometer at frequency of 10 MHz. Solutions at pH 9.0 behaved as most viscous and viscoelastic whereas those at pH 4.0 and 5.4 exhibited lower viscosity and viscoelasticity, respectively. Intrinsic viscosity, hydrophobicity, and conformational analysis could not account for the rheological behavior of IgG2 solutions. Zeta potential and light scattering measurements showed the significance of electroviscous and specific protein-protein interactions in governing rheology of IgG2 solutions. Specific protein-protein interactions resulted in formation of reversible higher order species of monomer. Solution storage modulus (G'), and not loss modulus or complex viscosity, was the more reliable parameter for predicting protein-protein interactions. Predictions about the nature of protein-protein interactions made on the basis of solution G' were found to be consistent with observed effect of pH and ionic strength on zeta potential and scattered intensity of IgG2 solutions. Results demonstrated the potential of high-frequency storage modulus measurements for understanding behavior of proteins in solutions and predicting the nature of protein-protein interactions.
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Affiliation(s)
- Atul Saluja
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, U-3092, 69 North Eagleville Road, Storrs, Connecticut 06269-3092, USA
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42
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Valente JJ, Fryksdale BG, Dale DA, Gaertner AL, Henry CS. Screening for physical stability of a Pseudomonas amylase using self-interaction chromatography. Anal Biochem 2006; 357:35-42. [PMID: 16843425 DOI: 10.1016/j.ab.2006.06.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 05/16/2006] [Accepted: 06/05/2006] [Indexed: 11/29/2022]
Abstract
Formulation development is an integral step in the successful commercialization of protein-based products in both the biotechnology and pharmaceutical industries. As the number of these protein formulations increases, so does the need for innovative approaches to characterize physical and chemical product stability. In this study, the osmotic second virial coefficient (B) of a commercial amylase was evaluated by self-interaction chromatography (SIC) as an innovative approach to characterize physical protein stability. B was measured as a function of pH and several common formulation additives (cosolvents), including sodium chloride, sucrose, and sorbitol. Cosolvent- and pH-induced physical stabilization of amylase is discussed in terms of positive shifts in B. Liquid chromatographic measurements of total soluble amylase and enzymatic activity measurements correlated qualitatively with trends in B except near the pI of amylase, where physical stability was minimal.
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Affiliation(s)
- Joseph J Valente
- Department of Chemistry, Colorado State University, Fort Collins, 80523, USA
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43
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Gitlin I, Carbeck JD, Whitesides GM. Warum sind Proteine geladen? Netzwerke aus Ladungs-Ladungs-Wechselwirkungen in Proteinen, analysiert über Ladungsleitern und Kapillarelektrophorese. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200502530] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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45
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Van roosmalen D, Dohmen-speelmans M, Dietz C, Van den broeke L, Van der Wielen L, Keurentjes J. Bioseparations in Aqueous Micellar Systems Based on Excluded-Volume Interactions. FOOD AND BIOPRODUCTS PROCESSING 2006. [DOI: 10.1205/fbp.05159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Valente JJ, Verma KS, Manning MC, Wilson WW, Henry CS. Second virial coefficient studies of cosolvent-induced protein self-interaction. Biophys J 2005; 89:4211-8. [PMID: 16199499 PMCID: PMC1366986 DOI: 10.1529/biophysj.105.068551] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Protein self-interaction is important in protein crystal growth, solubilization, and aggregation, both in vitro and in vivo, as with protein misfolding diseases, such as Alzheimer's. Although second virial coefficient studies can supply invaluable quantitative information, their emergence as a systematic approach to evaluating protein self-interaction has been slowed by the limitations of traditional measurement methods, such as static light scattering. Comparatively, self-interaction chromatography is an inexpensive, high-throughput method of evaluating the osmotic second virial coefficient (B) of proteins in solution. In this work, we used self-interaction chromatography to measure B of lysozyme in the presence of various cosolvents, including sucrose, trehalose, mannitol, glycine, arginine, and combinations of arginine and glutamic acid and arginine and sucrose in an effort to develop a better fundamental understanding of protein self-interaction in complex cosolvent systems. All of these cosolvents, alone or in combination, increased B, indicating a reduction in intermolecular attraction. However, the magnitude of cosolvent-induced changes in B was found to be largely dependent on the ability to control long-range electrostatic repulsion. To the best of our knowledge, this work represents the most comprehensive virial coefficient study to date focusing on complex cosolvent-induced effects on the self-interaction of lysozyme.
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Affiliation(s)
- Joseph J Valente
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, USA
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Ahamed T, Ottens M, van Dedem GWK, van der Wielen LAM. Design of self-interaction chromatography as an analytical tool for predicting protein phase behavior. J Chromatogr A 2005; 1089:111-24. [PMID: 16130779 DOI: 10.1016/j.chroma.2005.06.065] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Solution conditions under which proteins have a tendency to crystallize correspond to a slightly negative osmotic second virial coefficient (B22). A positive B22 value guarantees no crystallization to occur. On the other hand, a B22 value within the so called "crystallization slot" thermodynamically supports the crystallization processes but does not guarantee successful crystal growth. It is, however, a prerequisite for protein crystallization that the B22 value must be in the slightly negative regime. Self-interaction chromatography (SIC) is designed in this work as an analytical tool for determining B22 in a precise and reproducible way. The methodology was demonstrated in detail in terms of its theoretical basis, experimental methodology, troubleshooting and data analysis for different protein samples and solution conditions. The inherent error limit of SIC is found to be comparatively less than other B22 measurement techniques. The designed experimental approach was applied for mapping crystallization conditions of a model protein, i.e. lysozyme. Good agreement between the obtained lysozyme B22 values and literature values confirms the accuracy of the approach.
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Affiliation(s)
- Tangir Ahamed
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
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Cvetkovic A, Picioreanu C, Straathof AJJ, Krishna R, van der Wielen LAM. Quantification of Binary Diffusion in Protein Crystals. J Phys Chem B 2005; 109:10561-6. [PMID: 16852280 DOI: 10.1021/jp050289c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The use of confocal laser scanning microscopy for visualization and quantification of binary diffusion within anisotropic porous material is described here for the first time. The dynamics of adsorption profiles of dianionic fluorescein, zwitterionic rhodamine B, and their mixture in the cationic native orthorhombic lysozyme crystal were subsequently analyzed. All data could be described by a classical pore diffusion model. There was no change in the adsorption characteristics, but diffusion decreased with the introduction of a second solute in the solution. It was found that diffusion is determined by the combination of steric and electrostatic interactions,while adsorption is dependent on electrostatic and hydrophobic interactions. Thus, it was established that the outcome of binary transport depends on the solute, protein, and crystal characteristics.
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Affiliation(s)
- Aleksandar Cvetkovic
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
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Liu W, Cellmer T, Keerl D, Prausnitz JM, Blanch HW. Interactions of lysozyme in guanidinium chloride solutions from static and dynamic light-scattering measurements. Biotechnol Bioeng 2005; 90:482-90. [PMID: 15778988 DOI: 10.1002/bit.20442] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The interactions of partially unfolded proteins provide insight into protein folding and protein aggregation. In this work, we studied partially unfolded hen egg lysozyme interactions in solutions containing up to 7 M guanidinium chloride (GdnHCl). The osmotic second virial coefficient (B(22)) of lysozyme was measured using static light scattering in GdnHCl aqueous solutions at 20 degrees C and pH 4.5. B(22) is positive in all solutions, indicating repulsive protein-protein interactions. At low GdnHCl concentrations, B(22) decreases with rising ionic strength: in the absence of GdnHCl, B(22) is 1.1 x 10(-3) mLmol/g(2), decreasing to 3.0 x 10(-5) mLmol/g(2) in the presence of 1 M GdnHCl. Lysozyme unfolds in solutions at GdnHCl concentrations higher than 3 M. Under such conditions, B(22) increases with ionic strength, reaching 8.0 x 10(-4) mLmol/g(2) at 6.5 M GdnHCl. Protein-protein hydrodynamic interactions were evaluated from concentration-dependent diffusivity measurements, obtained from dynamic light scattering. At moderate GdnHCl concentrations, lysozyme interparticle interactions are least repulsive and hydrodynamic interactions are least attractive. The lysozyme hydrodynamic radius was calculated from infinite-dilution diffusivity and did not change significantly during protein unfolding. Our results contribute toward better understanding of protein interactions of partially unfolded states in the presence of a denaturant; they may be helpful for the design of protein refolding processes that avoid protein aggregation.
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Affiliation(s)
- Wei Liu
- Chemical Engineering Department, University of California, Berkeley, CA 94720, USA
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