Modeling and simulation of protein elution in linear pH and salt gradients on weak, strong and mixed cation exchange resins applying an extended Donnan ion exchange model

Wittkopp, Felix; Peeck, Lars H.; Hafner, Mathias; Frech, Christian

doi:10.1016/j.chroma.2018.02.020

Cited by 10 publications

(8 citation statements)

References 84 publications

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“…Slight deviations on the equilibrium constant, for both proteins, can be observed at high pH values. This is due to the fact that at low salt concentration and high pH values, the Donnan effect is exacerbated [30]. This phenomenon is not included in the model used in this investigation, and in Section 4.3, the importance of the environmental conditions the protein is exposed will be discussed.…”

Section: Resultsmentioning

confidence: 99%

“…In this work, LGE experiments were performed by a linear increase in the counterion concentration over time at a fixed pH value. The correlation of the normalized gradient slope and the retention factor

A_{i}

is described as [30]:

\begin{matrix} true \\ left \frac{d G H_{salt}}{d c_{s, normalelu}} = \frac{1}{k_{d, i} \cdot A_{i} + k_{d, i} - 1} \\ left = {[k_{d, i} \cdot (\exp (- \frac{Δ {\overset{G}{true}}_{i}^{0}}{R T} + ν_{i} \cdot \frac{Δ {\overset{G}{true}}_{s}^{0}}{R T}) \cdot {((), \frac{normalΛ}{c_{s}})}^{ν_{i}}) + k_{d, i} - 1]}^{- 1} \end{matrix}

where

c_{s, normalelu}

is the eluting salt concentration,

k_{d, i}

is the exclusion factor of the protein, and the normalized gradient slope GH is given as [31]:

\begin{matrix} true \\ right G H_{salt} & = & left g_{normalsalt} \cdot ((), V_{c} \cdot ((), 1 - ε) \cdot ε_{P}) \\ = & left \frac{c_{normalsalt, normalfinal} - c_{normalsalt, normalinitial}}{V_{g}} \cdot ((), V_{c} \cdot ((), 1 - ε) \cdot ε_{P}) \end{matrix}

…”

Section: Theoretical Considerationsmentioning

confidence: 99%

“…The SD model has some limitations since it is derived assuming a complete exclusion of co‐ions in the stationary phase, and the maximum uptake of counterions in the resin phase is equivalent to the ligand density. These assumptions lead to a complete disregard for the change in the protein charge caused by electrostatic interactions with the adsorbent surface (e.g., differences in the intraparticle pH), even though this effect has been extensively studied and shown in the literature [30,35–38]. To investigate this effect further, the ratio of the ion concentrations between the adsorbate and the liquid phase (

r_{D}

) was calculated by using the equation presented by Wittkopp et al.…”

Section: Theoretical Considerationsmentioning

confidence: 99%

“…To investigate this effect further, the ratio of the ion concentrations between the adsorbate and the liquid phase (

r_{D}

) was calculated by using the equation presented by Wittkopp et al. [30]

r_{D} = \frac{c_{C l^{-}}^{R}}{c_{C l^{-}}^{B}} = \frac{normalΛ}{2 c_{C l^{-}}^{B}} + \sqrt{S_{C l^{-}, O H^{-}} S_{N a^{+}, H^{+}} + {((), \frac{normalΛ}{2 c_{C l^{-}}^{B}})}^{2}}

…”

Section: Theoretical Considerationsmentioning

confidence: 99%

“…As long as the system contains only NaCl, and the pH is not to low or high (i.e., the concentrations of OH − and H + are small compared to the concentration of other ions), Equation (27) can be applied. For simplicity, in this work, the selectivity of all ions was set to 1, an assumption that has been proven to be pertinent in previous publications [30,37,39]. Hence, the pH value in the resin phase pH R can be calculated as:

p {normalH}_{R} = p {normalH}_{B} + \log_{10} (r_{D})

where pH B refers to the pH value in the mobile phase.…”

Section: Theoretical Considerationsmentioning

confidence: 99%

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Mechanistic modeling of ligand density variations on anion exchange chromatography

Sanchez-Reyes

Graalfs

Hafner

et al. 2020

J of Separation Science

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Ion exchange chromatography is a powerful and ubiquitous unit operation in the purification of therapeutic proteins. However, the performance of an ion‐exchange process depends on a complex interrelationship between several parameters, such as protein properties, mobile phase conditions, and chromatographic resin characteristics. Consequently, batch variations of ion exchange resins play a significant role in the robustness of these downstream processing steps. Ligand density is known to be one of the main lot‐to‐lot variations, affecting protein adsorption and separation performance. The use of a model‐based approach can be an effective tool for comprehending the impact of parameter variations (e.g., ligand density) and their influence on the process. The objective of this work was to apply mechanistic modeling to gain a deeper understanding of the influence of ligand density variations in anion exchange chromatography. To achieve this, 13 prototype resins having the same support as the strong anion exchange resin Fractogel® EMD TMAE (M), but differing in ligand density, were analyzed. Linear salt gradient elution experiments were performed to observe the elution behavior of a monoclonal antibody and bovine serum albumin. A proposed isotherm model for ion exchange chromatography, describing the dependence of ligand density variations on protein retention, was successfully applied.

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Section: Resultsmentioning

confidence: 99%

A_{i}

is described as [30]:

\begin{matrix} true \\ left \frac{d G H_{salt}}{d c_{s, normalelu}} = \frac{1}{k_{d, i} \cdot A_{i} + k_{d, i} - 1} \\ left = {[k_{d, i} \cdot (\exp (- \frac{Δ {\overset{G}{true}}_{i}^{0}}{R T} + ν_{i} \cdot \frac{Δ {\overset{G}{true}}_{s}^{0}}{R T}) \cdot {((), \frac{normalΛ}{c_{s}})}^{ν_{i}}) + k_{d, i} - 1]}^{- 1} \end{matrix}

where

c_{s, normalelu}

is the eluting salt concentration,

k_{d, i}

is the exclusion factor of the protein, and the normalized gradient slope GH is given as [31]:

\begin{matrix} true \\ right G H_{salt} & = & left g_{normalsalt} \cdot ((), V_{c} \cdot ((), 1 - ε) \cdot ε_{P}) \\ = & left \frac{c_{normalsalt, normalfinal} - c_{normalsalt, normalinitial}}{V_{g}} \cdot ((), V_{c} \cdot ((), 1 - ε) \cdot ε_{P}) \end{matrix}

…”

Section: Theoretical Considerationsmentioning

confidence: 99%

r_{D}

) was calculated by using the equation presented by Wittkopp et al.…”

Section: Theoretical Considerationsmentioning

confidence: 99%

“…To investigate this effect further, the ratio of the ion concentrations between the adsorbate and the liquid phase (

r_{D}

) was calculated by using the equation presented by Wittkopp et al. [30]

r_{D} = \frac{c_{C l^{-}}^{R}}{c_{C l^{-}}^{B}} = \frac{normalΛ}{2 c_{C l^{-}}^{B}} + \sqrt{S_{C l^{-}, O H^{-}} S_{N a^{+}, H^{+}} + {((), \frac{normalΛ}{2 c_{C l^{-}}^{B}})}^{2}}

…”

Section: Theoretical Considerationsmentioning

confidence: 99%

p {normalH}_{R} = p {normalH}_{B} + \log_{10} (r_{D})

where pH B refers to the pH value in the mobile phase.…”

Section: Theoretical Considerationsmentioning

confidence: 99%

See 3 more Smart Citations

Mechanistic modeling of ligand density variations on anion exchange chromatography

Sanchez-Reyes

Graalfs

Hafner

et al. 2020

J of Separation Science

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Selection of Chromatographic Systems*

Schulte

2020

Preparative Chromatography

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A novel lipid droplets‐targeting fluorescent probe based on dicyanisophorone and carbazole for Cu²⁺ and its application

Cui

Meng

et al. 2022

J Chinese Chemical Soc

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A novel fluorescent probe, LCH, based on dicyanisophorone and carbazole, was prepared for the visual detection of Cu2+. The probe LCH could recognize Cu2+ by fluorescence quenching in EtOH/H2O (1/4, v/v) solution, which could be easily identified under the 365 nm UV lamp, and the detection limit was as low as 0.785 μM. The recognition mechanism of probe LCH with Cu2+ was determined by combining 1H NMR titration, MS, and theoretical calculations. Practical application experiments showed that probe LCH could be used to detect Cu2+ in the test strip experiments. Cell imaging experiments showed that the probe LCH owned good cell permeability and could be applied to the imaging of Cu2+ in HepG2 cells. In addition, fluorescence colocalization experiments showed that LCH could target lipid droplets. These results indicate that the probe LCH will have a good application prospect in environmental detection and clinical medicine.

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Modeling and simulation of protein elution in linear pH and salt gradients on weak, strong and mixed cation exchange resins applying an extended Donnan ion exchange model

Cited by 10 publications

References 84 publications

Mechanistic modeling of ligand density variations on anion exchange chromatography

Mechanistic modeling of ligand density variations on anion exchange chromatography

Selection of Chromatographic Systems*

A novel lipid droplets‐targeting fluorescent probe based on dicyanisophorone and carbazole for Cu²⁺ and its application

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Modeling and simulation of protein elution in linear pH and salt gradients on weak, strong and mixed cation exchange resins applying an extended Donnan ion exchange model

Cited by 10 publications

References 84 publications

Mechanistic modeling of ligand density variations on anion exchange chromatography

Mechanistic modeling of ligand density variations on anion exchange chromatography

Selection of Chromatographic Systems*

A novel lipid droplets‐targeting fluorescent probe based on dicyanisophorone and carbazole for Cu2+ and its application

Contact Info

Product

Resources

About

A novel lipid droplets‐targeting fluorescent probe based on dicyanisophorone and carbazole for Cu²⁺ and its application