Adsorption Behavior of Multicomponent Protein Mixtures Containing α1-Proteinase Inhibitor with the Anion Exchanger, 2-(Diethylamino)ethyl-Spherodex

Abstract

The equilibrium binding behavior of alpha 1-proteinase inhibitor (alpha 1-PI) in the presence of human serum albumin (HSA) has been determined in packed bed systems with the anion exchanger, 2-(diethylamino)ethyl (DEAE)-Spherodex. Experimental data derived for the individual proteins were compared with the corresponding data obtained from batch adsorption studies as well as studies in which mixtures of these two proteins were loaded at different concentration ratios onto columns of the same anion exchange adsorbent. The results confirm that alpha 1-PI has a greater affinity for the anion exchanger, although competitive adsorption was observed as the inlet concentration of HSA was increased. Under these conditions, decreased binding capacities and lower dynamic adsorption rates were observed for alpha 1-PI with the DEAE-Spherodex anion exchange adsorbent. The results are discussed in terms of the influence which various contaminants that occur in multicomponent mixtures of proteins from human plasma can have on the equilibrium binding characteristics of a target protein with weak or strong ion exchange adsorbents under conditions approaching concentration overload in preparative chromatographic systems. These investigations have also addressed, as the first part of an iterative approach for the simulation of the adsorption behavior of multicomponent mixtures of human plasma proteins with ion exchange and affinity chromatographic adsorbents, the ability of noncompetitive and competitive Langmuirean models to simulate the adsorption of alpha 1-PI in the presence of different concentrations of HSA to DEAE-Spherodex.

Lumped parameter model for prediction of initial breakthrough profiles for the chromatographic capture of antibodies from a complex feedstock

“…The 26% difference in Q max in ( [37] reported a value of 5.06 M. The high values found in this work with a complex feedstock cf. those with monocomponent systems [16,34,37] were not unexpected, given that all MT limitations are included in K D with a lumped parameter approach [2,9], and Finette et al [11] came up with similar findings in their single-versus multi-component surface adsorption study.…”

“…Attempts have been made with two-component systems [10,11] to develop models of batch adsorption isotherms, incorporating the competition between molecules, where parameter determination was performed in pure solutions. However, applying this approach to a complex feedstock would require individual parameters to be determined for each component, or a number of the main contaminants in addition to the target molecule, again potentially leading to lengthy computations, and limiting the direct application of such models.…”

Optimization Considerations for the Purification of α1‐Antitrypsin Using Silica‐Based Ion‐Exchange Adsorbents in Packed and Expanded Beds

“…Procedure for the Rocket Immunoelectrophoresis. The procedures for the rocket immunoelectrophoresis were based on methods adapted in this laboratory (16) from previously reported Laurell rocket protocols (17).…”

“…Breakthrough curves were thus generated during each step. Other details on the equipment setup for these chromatographic experiments and the methods used for the collection of fractions and the evaluation of the frontal analysis breakthrough profiles were based on approaches developed in this laboratory for other protein systems that have been described elsewhere (16,18,19).…”

Competitive adsorption

“…Considerable attention has been given to the multicomponent adsorption of proteins since this problem has great practical significance [16,17,48,[152][153][154][155][156][157][158][159]. Progress in the study of proteins and other biomacromolecules is largely a function of developments in the retention and identification in biomaterials in a broad concentration range (from 10 -3 M to individual molecules) [48].…”