M. Benčina, K. Benčina, A. Štrancar, A. Podgornik

Journal of Chromatography A, 1065 (2005) 83–91(2005) 83–91

A deoxyribonuclease bioreactor was prepared by immobilization of deoxyribonuclease I through epoxy groups inherently present on poly (glycidyl methacrylate-co-ethylene dimethacrylate) monoliths. Columns with various levels of DNase activity were prepared varying immobilization temperature, pH, time and method. The apparent Michaelis–Menten constant, Kmapp, and turnover number, k3app, for immobilized DNase determined by on-line frontal analysis method were, respectively, 0.28 g of DNA l-1 and 16 dA260nm min-1 mg-1 of immobilized DNase. The highest activity of immobilized DNase was detected at 1 mM calcium ions concentration and mirrored properties of free enzyme; however, reaction temperature in the range from 25 to 37 °C has no significant effect on activity of immobilized DNase in contrary to free enzyme. The CIM DNase bioreactor was used for elimination of DNA contaminants in RNA samples prior to reverse transcription followed by PCR.

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M. Benčina, J. Babič, A. Podgornik

Journal of Chromatography A, 1144 (2007) 135–142

In gene therapy and DNA vaccination, RNA removal from DNA preparations is vital and is typically achieved by the addition of ribonuclease into the sample. Removal of ribonuclease from DNA samples requires an additional purification step. An alternative is the implementation of immobilized ribonuclease. In our work, ribonuclease was covalently coupled onto the surface of methacrylate monoliths via epoxy or imidazole carbamate groups. Various immobilization conditions were tested by changing immobilization pH. Ribonuclease immobilized on the monolith via imidazole carbamate groups at pH 9 was found to be six times more active than the ribonuclease immobilized on the monolith via epoxy groups. Under optimal immobilization conditions the Michaelis–Menten constant, Km, for cytidine-2,3-cyclic monophosphate, and turnover number, k3 were 0.52 mM and 4.6 s-1, respectively, and mirrored properties of free enzyme. Enzyme reactor was found to efficiently eliminate RNA contaminants from DNA samples. It was active for several weeks of operation and processed 300 column volumes of sample. Required residence time to eliminate RNA was estimated to be around 0.5 min enabling flow rates above 1 column volume per min.

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Y.-P. Lim, D. Josić, H. Callanan, J. Brown, D. C. Hixson

Journal of Chromatography A, 1065 (2005) 39–43(2005) 39–43

Epoxy-activated monolithic CIM disks seem to be excellent supports for immobilization of protein ligands. The potential use of enzymes, immobilized on monolithic disks for rapid preparative cleavage proteins in solution was investigated. Digestion of complex plasma proteins was demonstrated by using inter-alpha inhibitors with elastase, immobilized on epoxy-activated CIM disks. Recently, a monoclonal antibody against human inter-alpha inhibitor proteins (MAb 69.31) was developed. MAb 69.31 blocks the inhibitory activity of inter-alpha inhibitor proteins to serine proteases. These results suggest that the epitope defined by this antibody is located within or proximal to the active site of the inhibitor molecule. This antibody, immobilized on monolithic disk, was used for very rapid isolation of inter-alpha proteins. The isolated complex protein was used for enzymatic digestion and isolation of cleavage products, especially from inter-alpha inhibitor light chain to elucidate precisely the target sequence for MAb 69.31 by N-terminal amino acid sequencing. Bovine pancreatic elastase immobilized on monolithic disk cleaves inter-alpha inhibitor protein complex into small fragments which are still reactive with MAb 69.31. One of these proteolytic fragments was isolated and partially sequenced. It could be shown that this sequence is located at the beginning of two proteinase inhibitor domains of the inter-alpha inhibitor light chain (bikunin). Elastase immobilized on monolithic disk offers a simple and rapid method for preparative isolation of protease cleavage fragments. The immobilized enzyme is stable and still active after repeated runs. A partial or complete digestion can be achieved by varying the flow rate.

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E. G. Vlakh, A. Tappe, C. Kasper, T. B. Tennikova

Journal of Chromatography B, 810 (2004) 15–23

Plasminogen activators are the proteases which convert plasminogen into plasmin dissolving, in its turn, the major component of blood clots, fibrin. They are extremely useful in heart attack therapy. Modern and most appropriate way of scaled up production of these valuable proteins is gene engineering. In this case, a separation and a purification of target product become the important steps of the whole process. Recently developed affinity chromatography on short monolithic columns seems to be a very attractive method for these purposes. High speed of a process prevents the protein’s denaturation due to temperature or/and solvents influence. The better mass transfer mechanism (convection rather than diffusion) allows considering only biospecific complexing as time limiting step. Specificity of several synthetic peptides to plasminogen activators have been studied by affinity chromatography on short monolithic columns. Peptide ligands were synthesized by conventional solid phase peptide synthesis (SPPS). The immobilization procedure was carried out as a one step process at static conditions. The results of quantitative evaluation of such affinity interactions were compared with those established for plasminogen that is the natural affinity counterpart to both proteases. Additionally, some of investigated peptides were synthesized directly on GMA–EDMA disks and their affinity properties were compared with those established for the case of immobilized ligands. The possibility of using of synthetic peptidyl ligands for plasminogen activators isolation from native cell supernatant and model protein mixtures has been demonstrated.

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N. D. Ostryanina, G. P. Vlasov, T. B. Tennikova

Journal of Chromatography A, 949 (2002) 163–171

High-performance monolithic disk chromatography (HPMDC), including its affinity mode, is a very efficient method for fast separations of biological molecules of different sizes and shapes. In this paper, protein and peptide ligands, immobilized on the inner surface of thin, monolithic supports (Convective Interaction Media or CIM® disks), have been used to develop methods for fast, quantitative affinity fractionation of pools of polyclonal antibodies from blood sera of rabbits, immunized with complex protein–peptide conjugates. The combination of several disks with different affinity functionalities in the same cartridge enables the separation of different antibodies to be achieved within a few minutes. The apparent dissociation constants of affinity complexes were determined by frontal analysis. Variation of elution flow rate over a broad range does not affect the affinity separation characteristics. Indifferent synthetic peptides used as biocompatible spacers do not change the affinity properties of the ligands. The highly reproducible results of immunoaffinity HPMDC are compared with data obtained by widely used enzyme-linked immunosorbent assay.

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A. Tscheliessnig, A. Jungbauer

Journal of Chromatography A, 1216 (2009) 2676–2682

High-performance monolith affinity chromatography employing protein A resins has been introduced previously for the fast purification of IgG from different sources. Here we describe the design and evaluation of a fast and specific method for quantitation of IgG from purified samples as well as crude supernatant from Chinese hamster ovary (CHO) cells. We used a commercially available affinity monolith with protein A as affinity ligand (CIM protein A HLD disk). Interferences of CHO host cell proteins with the quantitation of IgG from CHO supernatant were eliminated by a careful choice of the equilibration buffer. With this method developed, it is possible to quantify IgG within 5 min in a concentration range of 23–250 μg/ml. The calibration range of the method could be extended from 4 to 1000 μg/ml by adjusting the injection volume. The method was successfully validated by measuring the low limit of detection and quantification, inter- and intra-day precision and selectivity.

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C. Kasper, L. Meringova, R. Freitag, T. Tennikova

Journal of Chromatography A, 798 (1998) 65-72

A fast affinity method for the semi-preparative isolation of recombinant Protein G from E. coli cell lysate is proposed. Rigid, macroporous affinity discs based on a glycidyl methacrylate–co-ethylene dimethacrylate polymer were used as chromatographic supports. The specific ligands (here human immunoglobulin G, hIgG) were immobilized by the one-step reaction between native epoxy groups of the polymer surface and ϵ-amino groups of the IgG molecules. No intermediate spacer was necessary to reach full biological activity of the ligand. The globular affinity ligands are located directly on the pore wall surface and are thereby freely accessible to target molecules (here Protein G) migrating with the mobile phase through the pores. It is shown that the conditions chosen for the hIgG immobilization do not involve an active site of the protein and thus do not bias the formation of the affinity complex. Chromatographically determined constants of dissociation of hIgG–Protein G affinity complexes confirm the high selectivity of this separation method. Two different aspects of the affinity separation are discussed, which differ mostly in terms of scale. In disc chromatography, high volumetric flow velocities are possible because of the small backpressure. Since in addition the mass transfer is more efficient, it becomes possible to achieve very short analysis times. The discs proposed can be used in a single-step enrichment of Protein G from lysates of non-pathogenic E. coli. Gel electrophoresis data are used to demonstrate the high degree of purity achieved for the final product.

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M. Žorž

ChemieXtra 3/2012 pp 30-33

BIA Separations produziert und vertreibt kurze monolithischen Chromatografiesäulen, die auf der CIM-Convective Interaction Media-Technologie basieren. CIM-Säulen eignen sich vor allem für die Reinigung von grossen Biomolekülen wie etwa Viren (virale Vektoren und Impfstoffe), DNA (Plasmid-DNA) und grössere Proteine (Immunglobuline G und M, pegylierte Proteine). Sie weisen einzigartige Eigenschaften in Bezug auf operative Flussraten, Adsorptionsfähigkeit und Trennung grosser Biomoleküle auf. Die Säulen werden in Forschung, Labor, Pilot- und industriellen Produktionsstufen eingesetzt und sind extrem einfach zu handhaben.

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D. G. Glover, M. Barut, A. Podgornik, M. Peterka, A. Štrancar

BioProcess International, Oct 2004, 58-63

The sequencing of the human genome and the rise of proteomics have increased the numbers of potential therapeutic targets. Biotechnology companies need to increase productivity, decrease discovery and production costs, and use technologies that easily transfer across departments if they wish to remain competitive. The most important tools are those for separation (purification) of target substance(s). They should be easy to use and offer an identical performance and purification profile no matter where they are implemented — in discovery, production, or quality assurance (QA).

CIM Convective Interaction Media short monolithic columns are just such a unifying technology. Produced in shapes and sizes from microliter to liter scale, they represent an evolutionary approach to meeting biochromatographic separation requirements in research and product development. Able to withstand 1 M NaOH with no loss of capacity or resolution, these easily scalable columns have been optimized for analysis and cGMP production of complex biomolecules ranging from oligonucleotides and plasmid DNA (pDNA) to proteins and viruses.

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I. Mihelič, T. Koloini, A. Podgornik, M. Barut, A. Štrancar

Acta Chim. Slov. 2001, 48, 551-564

Monolithic stationary phases are becoming very important field of liquid chromatography. Methacrylate based CIM Convective Interaction Media® monolithic columns and are produced via radical polymerization, which results in a rigid and chemically very stable porous monolithic structure. Some characteristics of small-scale monolithic columns and an example of extremely fast separation of biomolecules are presented in the paper. However, the preparation of large and homogeneous monolithic columns represents a big problem, because the heat released during the polymerization causes distortion of the monolithic structure. A mathematical model employing the polymerization kinetics for the prediction of the temperature profiles and a comparison with the experimental results is presented with the emphasis on the conversion and the rate od the heat release profiles. Finally, the characteristics of a large-scale monolithic column are presented.

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I. Mihelič, A. Podgornik, T. Koloini

Journal of Chromatography A, 987 (2003) 159–168

This work investigates the influence of temperature on the binding capacity of bovine serum albumin (BSA), soybean trypsin inhibitor and l-glutamic acid to a CIM® (DEAE) weak anion-exchange disk monolithic column. The binding capacity was determined experimentally under dynamic conditions using frontal analysis. The effect on the dynamic binding capacity of dimers present in the BSA solution has been evaluated and a closed-loop frontal analysis was used to determine the equilibrium binding capacities. The binding capacity for both BSA and soybean trypsin inhibitor increased with increasing temperature. In the case of l-glutamic acid, an increase in the binding capacity was observed with temperature up to 20 °C. A further increase in temperature caused a decrease of the dynamic binding capacity.

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P. Kramberger, D. Glover, A. Štrancar

American Biotechnology Laboratory, 2003, 27-28

Research in molecular and cell biology has shown that macromolecules such as pDNA and virus vectors, together called nanoparticles, have the potential to assist in the prevention and treatment of some human diseases. The most important step in their production is the downstream processing (isolation and cleaning). Precipitation, ultrafiltration, and LC techniques are the most widely used for these purposes, but only LC can purify the product so that it is recognized as safe for therapeutic use.

Apart from reduced yield, downstream processing can cause minor or even major modifications in the structure of the biomolecule. Usually these modifications do not affect the activity of the product, but may change its antigenicity. Minimizing these changes to maintain product safety is the main objective in the downstream processing of nanoparticles. For the efficient isolation of labile biomolecules, liquid chromatographic supports should provide fast and efficient separation in order to decrease biomolecule degradation; have high, preferably flow-unaffected capacity and resolution; and exhibit low backpressure. They should be stable, even if harsh conditions are applied during sanitation (e.g., 1 MNaOH), and should be easy to handle and operate.

CIM® (Convection Interaction Media) monolithic chromatographic columns (BIA Separations, Ljubljana, Slovenia) meet all of these requirements. This application note will discuss the columns and their use on human models and plant viruses and pDNA.

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P. Gagnon

Roadmap to Process Development, issue 3/2010, Bia Separations

The first two articles in this series addressed column selectivity and capacity. This article discusses how to apply results from these preliminary studies to create fully functional multi-step purification procedures. The principles described here can be applied to proteins, plasmids, or virus particles.

Process modeling represents a nexus at which the theoretical ideals of purification meet the practical limitations of the laboratory, or in less elegant terms: where the rubber meets the road. The key theoretical principle is the notion of developing an orthogonal purification process. Orthogonal means pertaining to right angles. In purification terms, it translates to combining purification methods that are highly complementary to one another. Its value resides in the presumption that different purification methods bind the product by different sites, along with a unique subset of contaminants. The more complementary the methods, the lower the overlap in contaminant subsets, and the higher the purification factor offered by the particular combination of methods.

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J. Subotič, K. Koruza, B. Gabor, M. Peterka, M. Barut, J. Kos, J. Brzin

Affinity Chromatography, Dr. Sameh Magdeldin (Ed.), ISBN: 978-953-51-0325-7, InTech

Proteolytic enzymes (also known as proteases, proteinases or peptidases) offer a wide range of applications. They are routinely used in detergent, leather, food and pharmaceutical industries, as well as in medical and basic research. Therefore, effective isolation procedures are of great importance. The chapter describes the use of recently discovered protease inhibitors from basidiomycetes as affinity chromatography ligands for isolating proteases. Affinity columns with serine and cysteine protease inhibitors immobilized to the natural polymer Sepharose have been prepared, the chromatography procedure optimized and used for isolating proteases from various bacterial, plant and animal sources. The cysteine protease inhibitor macrocypin showed superior characteristics as a ligand, so was selected for immobilization to CIM (Convective Interaction Media) monolithic disks. Different immobilization chemistries and process conditions were optimized to determine the best conditions for high capacity and selectivity. A very effective method for isolating cysteine proteases was developed using affinity chromatography with the fungal cysteine protease inhibitor macrocypin immobilized to a CIM monolithic disk.

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T. Tennikova, A. Štrancar

LabPlus international February - March 2002, Volume 16

Monolithic supports are a novel generation of stationary phases that can be used for liquid and gas chromatography, capillary electrochromatography, bioconversions, as well as supports for solid phase synthesis. In contrast to individual particles packed into chromatographic columns, monolithic supports are cast as continuous homogeneous phases. They provide high rates of mass transfer at lower pressure drops and enable much faster separations. In addition to the speed, the nature of the pores allows easy permeability for large molecules. Monolithic supports are thus the method of choice for the separation of proteins, oligonucleotides, and nanoparticles such as pDNA and viruses. In this article we review the application of the monlithic columns to bioaffinity chromatography.

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K. Pflegerl, A. Podgornik, E. Berger, A. Jungbauer

Biotechnology and Bioengineering 79 (2002) 733-740

Screening of peptide ligands for affinity chromatography usually involves incubation with the target protein in a batch system. In an additional step, peptides with fast binding kinetics have to be selected in respect to satisfactory performance under flow conditions on a support ensuring optimal three-dimensional presentation of the peptide. We have developed a rapid screening system based on peptide synthesis and screening on CIM® disks. The disk size was minimized to fit into microplates usually applied for solid-phase extraction. In combination with a vacuum manifold, semi-automated peptide synthesis and screening for binding to a target protein under simulated chromatography conditions are possible. Various analytical methods can be applied for parallel and automated determination of the quantity, integrity, or activity of the target protein in the flow through or bound to the affinity support. This system also allows parallel screening for suitable chromatographic conditions like running buffer, washing, and elution conditions. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 733–740, 2002.

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D. Josić, A. Buchacher

J. Biochem. Biophys. Methods 49 (2001) 153–174

Monoliths are useful chromatographic supports, as their structure allows improved mass transport. This results in fast separation. Once the ligand of interest has been immobilized, chromatographic separation can also be accomplished in affinity mode. Ligands with low molecular mass have been shown to be the easiest to immobilize. Nowadays, ligands with low molecular mass are often designed by combinatorial chemical techniques. In addition, many applications have been described where ligands with high molecular mass, such as Proteins A and G, antibodies, lectins and receptors are used.

The immobilization of an enzyme on the monolithic support creates a flow-through reactor. Small proteins, such as carbonic anhydrase, can be directly immobilized on the support. However, in the case of large molecules, the active center of the enzyme is no longer accessible at all or only to a limited degree. An improvement can be achieved by introducing a spacer, which allows maximum enzymatic conversion. Fast conversion of substrates with high molecular mass has been investigated with immobilized trypsin. It was shown that in case of high-molecular-mass substrates, the conversion rate depends very much on the flow-rate. Most applications described have been performed on an analytical or semi-preparative scale. However, the technical problems of up-scaling are close to being definitely solved, enabling enzymatic conversion on a preparative scale in the future.

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E. G. Vlakh, A. Tappe, C. Kasper, T. B. Tennikova

Journal of Chromatography B, 810 (2004) 15–23

Plasminogen activators are the proteases which convert plasminogen into plasmin dissolving, in its turn, the major component of blood clots, fibrin. They are extremely useful in heart attack therapy. Modern and most appropriate way of scaled up production of these valuable proteins is gene engineering. In this case, a separation and a purification of target product become the important steps of the whole process. Recently developed affinity chromatography on short monolithic columns seems to be a very attractive method for these purposes. High speed of a process prevents the protein’s denaturation due to temperature or/and solvents influence. The better mass transfer mechanism (convection rather than diffusion) allows considering only biospecific complexing as time limiting step. Specificity of several synthetic peptides to plasminogen activators have been studied by affinity chromatography on short monolithic columns. Peptide ligands were synthesized by conventional solid phase peptide synthesis (SPPS). The immobilization procedure was carried out as a one step process at static conditions. The results of quantitative evaluation of such affinity interactions were compared with those established for plasminogen that is the natural affinity counterpart to both proteases. Additionally, some of investigated peptides were synthesized directly on GMA–EDMA disks and their affinity properties were compared with those established for the case of immobilized ligands. The possibility of using of synthetic peptidyl ligands for plasminogen activators isolation from native cell supernatant and model protein mixtures has been demonstrated.

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S. Neff, A. Jungbauer

Journal of Chromatography A, 1218 (2011) 2374–2380

We have developed a method for quantification of a specific monoclonal IgM directed toward embryonic stem cells based on a peptide affinity monolith. A peptide affinity ligand with the sequence C–C–H–Q–R–L–S–Q–R–K was obtained by epitope mapping using peptide SPOT synthesis. The peptide ligand was covalently immobilized by coupling the N-terminal cysteine to a monolithic disk that was previously modified with iodated spacer molecules. The monolithic disc was used for quantification of purified IgM and for IgM present in mammalian cell culture supernatant. We observed 17% unspecific binding of IgM to the monolithic disk and additionally a product loss in the flow through of 20%. Nevertheless, calibration curves had high correlation coefficients and inter/intra-assay variability experiments proved sufficient precision of the method. A limit of quantification of 51.69 μg/mL for purified IgM and 48.40 μg/mL for IgM in cell culture supernatant could be calculated. The binding capacity was consistent within the period of the study which included more than 200 cycles. The analysis time of less than 2 min is an advantage over existing chromatographic methods that rely on pore diffusion.

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R. D. Arrua, C. I. Alvarez Igarzabal

J. Sep. Sci. 2011, 34, 1974–1987

In the early 1990s, three research groups simultaneously developed continuous macroporous rod-shaped polymeric systems to eliminate the problem of flow through the interparticle spaces generally presented by the chromatography columns that use particles as filler. The great advantage of those materials, forming a continuous phase rod, is to increase the mass transfer by convective transport, as the mobile phase is forced to go through all means of separation, in contrast to particulate media where the mobile phase flows through the interparticle spaces. Due to their special characteristics, the monolithic polymers are used as base-supports in different separation techniques, those chromatographic processes being the most important and, to a greater extent, those involving the separation of biomolecules as in the case of affinity chromatography. This mini-review reports the contributions of several groups to the development of macroporous monoliths and their modification by immobilization of specific ligands on the products for their application in affinity chromatography.

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