Adsorption of human immunoglobulin G onto ethacrylate and histidine-linked methacrylate

Abstract

The adsorption of human IgG onto GMA (a semirigid methacrylate-based chromatography matrix) and His-GMA adsorbents was studied by chromatography and batch equilibrium binding analysis. IgG molecules adsorbed onto GMA gel by nonspecific hydrophobic interactions and the specificities were similar for both adsorbents. Adsorption data were analyzed using three isotherm models, namely the Langmuir, Freundlich and Langmuir-Freundlich models, and the adsorption parameters were computed. The experimental isotherms were best described by a combined Langmuir-Freundlich model, which indicated the presence of unequal binding sites on both adsorbents and/or positive cooperativity in the binding of the IgG molecules

Dual targeting improves microbubble contrast agent adhesion to VCAM-1 and P-selectin under flow

“…The Langmuir-Freundlich isotherm for protein adsorption[21] was used to fit all protein adsorption results. This isotherm is given by $B=\frac{B_{max}\ast F^n}{K_a+F^n}$, where B corresponds to bound molecules/μm 2 , F denotes the free molecules available for binding, B max is the maximum binding capacity, K a denotes the adsorption constant for the protein and n is the Langmuir-Freundlich parameter.…”

Characterisation of an industrial affinity process used in the manufacturing of digoxin-specific polyclonal Fab fragments

“…The data obtained from these 24 h equilibrium experiments were evaluated employing the Langmuir-Freundlich correlation given in Eq. (1) [17][18][19][20]:…”

“…3). A positive initial slope, characteristics of positive coopperativity [17][18][19][20] in Table 3 Comparison between production (data from Protherics UK Ltd., DigiFab TM manufacturing run) and scale down runs c Papain concentration (contamination from previous digestion stage) − product specification = 0.1% (w/w) (weight of papain/weight of total protein in elution). d Fc concentration − product specification = 0.2% (w/w) (weight of Fc/weight of total protein in elution).…”

“…3) indicates deviation from Langmuir behaviour and so a Langmuir-Freundlich (this can describe both concave up and concave down curves) model was used to calculate the maximum capacity of the column (Q m ), by fitting experimental values of C s and C m to Eq. (1) [17,18] using SigmaPlot (Systat Software Ltd.). SigmaPlot uses iteration to find the coefficients that give the best fit between the equation and the data [17].…”

Thermodynamic parameters for Eu(III) binding to Datura innoxia root material

“…3" rend="display" xml:id="FD3">$$\mathrm{normalq}=[\mathrm{normalM}{false({\mathrm{KC}}_{\mathrm{eq}}false)}^{\mathrm{\beta }}]/[1+{false({\mathrm{KC}}_{\mathrm{eq}}false)}^{\mathrm{\beta }}]$$where q represents the amount adsorbed, M the maximum adsorption, and C eq the adsorbate’s equilibrium concentration [Aquino, et al, 2003]. K m represents the equilibrium constant and β is then the Langmuir-Freundlich coefficient [Aquino, et al, 2003]. Because of the presence of three separate parameters, numerical methods are typically required for extraction of M, K, and β.…”