Immuno-affinity partition of cells in aqueous polymer two-phase systems

Karr, Laurel J.; Shafer, Steven G.; Harris, J. Milton; Alstine, James M. Van; Snyder, Robert S.

doi:10.1016/s0021-9673(01)87028-x

Cited by 63 publications

(15 citation statements)

References 14 publications

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“…In 2010 those three products had total sales of over $3.5 billion (USD) [7]. Many more Ab-fragments are under development [3,[8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

“…The latter is advantageous in some applications (see below). Ab-fragments, including fragment antigen-binding fragments (Fabs), single-chain variable fragments (scFvs), such as pexelizumab (Alexion), and single-domain antibody fragments (dAbs) (Figure 2 Although lack of an Fc region should reduce the circulation half-life of Ab fragments various recombinant chemical modifications such as "PEGylation" can enhance Ab-fragment circulation life [3,[12][13][14][15]. Cimzia® is one example of a PEGylated Ab fragment.…”

Section: Introductionmentioning

confidence: 99%

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Antibody Fragments and Their Purification by Protein L Affinity Chromatography

Rodrigo¹,

Gruvegard²,

Alstine

2015

Antibodies

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Antibodies and related proteins comprise one of the largest and fastest-growing classes of protein pharmaceuticals. A majority of such molecules are monoclonal antibodies; however, many new entities are antibody fragments. Due to their structural, physiological, and pharmacological properties, antibody fragments offer new biopharmaceutical opportunities. In the case of recombinant full-length antibodies with suitable Fc regions, two or three column purification processes centered around Protein A affinity chromatography have proven to be fast, efficient, robust, cost-effective, and scalable. Most antibody fragments lack Fc and suitable affinity for Protein A. Adapting proven antibody purification processes to antibody fragments demands different affinity chromatography. Such technology must offer the unit operation advantages noted above, and be suitable for most of the many different types of antibody fragments. Protein L affinity chromatography appears to fulfill these criteria-suggesting its consideration as a key unit operation in antibody fragment processing.

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“…In 2010 those three products had total sales of over $3.5 billion (USD) [7]. Many more Ab-fragments are under development [3,[8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Antibody Fragments and Their Purification by Protein L Affinity Chromatography

Rodrigo¹,

Gruvegard²,

Alstine

2015

Antibodies

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“…Another reason for reducing N is that negative effects of PEGylation on protein activity decrease with N and such factors are more dominant than the MW of the PEG coupled to the protein. In the case of antibodies and enzymes binding constants tend to directly decrease with N in a semilog manner (e. g. Chapman, 2002;Chapman et al, 1999;Clark et al, 1996;Karr et al, 1986;Veronese et al, 1992).…”

Section: Pegylation Site Chemistry and Polymer Engineeringmentioning

confidence: 99%

“…For example the log of the partition coefficient (K) of PEG-modified proteins between the two aqueous phases in a PEG-dextran two polymer, or PEG-salt two-phase system increases directly with degree of PEGylation of the protein (Delgado et al, 1997;Harris and Zalipsky, 1997;Karr et al, 1986). This is fortuitous as cell debris, endotoxin, some proteins and other contaminants often partition in favour of the non-PEG-rich phase.…”

Section: General Considerationsmentioning

confidence: 99%

“…However PEGylation may also eliminate binding depending on the site of modification. Karr et al noted that significantly PEGylated polyclonal antibody preparations were capable of recognising and binding antigen and could be used for immunoaffinity separations (Karr et al, 1986). They also noted that PEGmodified protein A was also capable of binding antibody (Karr et al, 1988).…”

Section: Immunoaffinity and Other Specific Affinity Interactionsmentioning

confidence: 99%

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PEG-proteins: Reaction engineering and separation issues

Fee

Alstine²

2006

Chemical Engineering Science

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217

171

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Poly(ethylene glycol)-conjugated (or PEGylated) proteins are an increasingly important class of therapeutic proteins that offer improved in vivo circulation half lives over their corresponding native forms. Their production involves covalent attachment of one or more poly(ethylene glycol) molecules to a native protein, followed by purification. Because of the extremely high costs involved in producing native therapeutic proteins it is important that subsequent PEGylation processes are as efficient as possible. In this paper, reaction engineering and purification issues for PEGylated proteins are reviewed. Paramount considerations for PEGylation reactions are specificity with respect to the conjugation site and overall yield. Batch PEGylation reaction methods are discussed, along with innovative methods using packed bed or "on-column" approaches to improve specificity and yield. Purification methods are currently dominated by ion exchange and size exclusion chromatography. Other methods in common use for protein separations, including hydrophobic interaction chromatography, affinity chromatography and membrane separations, are rarely used in PEGylated protein purification schemes. A better understanding of the effects of PEGylation on the physicochemical properties of proteins (isoelectric point, surface charge density and distribution, molecular size and relative hydrophobicity) and interactions between PEGylated proteins and surfaces is needed for the future development of optimal purification processes and media.

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A chemical modification of myeloperoxidase and lactoperoxidase with 2-(O-methoxypolyethylene glycol)-4,6-dichloro-s-triazine (activated PEG1)

Odajima

Onishi

1998

Cell Biochem. Funct.

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The modification of myeloperoxidase and lactoperoxidase with 2-(O-methoxypolethylene glycol)-4, 6-dichloro-s-triazine, an activated polyethylene glycol (PEG1), was investigated. The modification caused a shift of the Soret band in the light absorption spectrum, from 430 nm to 418 nm in the case of myeloperoxidase (native ferric form), and from 412 nm to 406 nm in the case of lactoperoxidase (native ferric form). PEG1-modified myeloperoxidase and PEG1-modified lactoperoxidase both failed to bind with antiserum to the respective native enzyme, but both retained respectively 4.5 +/- 0.3 per cent (mean +/- SE, n = 5) and 0.6 +/- 0.2 per cent (mean +/- SE, n = 5) of the activities of peroxidation of the hydrogen donor o-methoxyphenol in comparison with the native enzyme, and 1.5 +/- 0.2 per cent (mean +/- SE, n = 5) and 1.2 +/- 0.2 per cent (mean +/- SE, n = 5) of the activities of destruction of fuchsin basic in the presence of hydrogen peroxide and a halide, bromide. The pH dependencies of the peroxidating activities were almost the same as those of the corresponding native enzymes, but both the optimal pHs of the reactions involving the destruction of fuchsin basic were shifted by approximately 1.0 pH unit toward neutral pH compared with the respective native enzymes.

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Immuno-affinity partition of cells in aqueous polymer two-phase systems

Cited by 63 publications

References 14 publications

Antibody Fragments and Their Purification by Protein L Affinity Chromatography

Antibody Fragments and Their Purification by Protein L Affinity Chromatography

PEG-proteins: Reaction engineering and separation issues

A chemical modification of myeloperoxidase and lactoperoxidase with 2-(O-methoxypolyethylene glycol)-4,6-dichloro-s-triazine (activated PEG1)

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