Variation of the carbohydrates of glycoproteins of cells growing on different surfaces

Warren, Leonard; Blithe, Diana L.; Cossu, Giulio

doi:10.1002/jcp.1041130105

Cited by 13 publications

(9 citation statements)

References 24 publications

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“…42 Similar effects were found using different culture media (serum-supplemented vs. serum-free) or in vitro production compared with production in mouse ascites. 333' The molecular integrity of monoclonal antibodies i s also affected using different production modes (e.g., batch vs. continuous culture).…”

Section: Introductionsupporting

confidence: 79%

Influence of cell‐ and media‐derived factors on the integrity of a human monoclonal antibody after secretion into serum‐free cell culture supernatants

Ackermann

Jäger

Marx

1995

Biotech & Bioengineering

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To investigate the effects of factors secreted by different cell lines on human monoclonal antibody (MAb) integrity, 600 mg of a human MAb, which specifically binds to human erythrocytes, were produced in a perfusion process. After purification by protein A affinity chromatography, the MAb was used for integrity testing in supernatants of several cell lines to investigate their potential to degrade the antibody in the extracellular environment. One insect cell line (IPLB-SF-21 AE) and four mammalian cell lines [CHO K1, BHK-21 (C13), C1271, P3-X63-Ag8.653], all of them commonly used for the production of recombinant proteins, and the human-human-mouse heterohybridoma cell line itself (H-CB-hahE), were adapted to serum-free culture media. For integrity testing all cell lines were cultivated in spinner flasks using serum-free media supplemented with 30 mug mL(-1) of purified MAb. MAb integrity was assayed by SDS polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing, both followed by Western blotting, and an antigen binding assay. None of the mammalian cells showed any detectable effects on antibody stability and integrity during exponential growth, whereas isoelectric focusing of monoclonal antibody taken from IPLB-SF-21 AE culture supernatants revealed a new band indicating a partial modification of the MAb by secreted factors of these cells. This observation did not correlate with the total proteolytic activity, which was measured in all supernatants and found to be lowest in the insest cell cultures. For mammalian cell cultures, it could be concluded from these findings that shifts of the antibody microheterogeneity pattern, which can be found normally as a result of variations in different production parameters, are not caused by extracellular factors once the product has been secreted into the supernatant. In addition to their well-known advantages in posttranslational modifications (e.g., formation of complex type N-glycans), mammalian cells appear to be more suitable as expression systems for human monoclonal antibodies to be used in vivo when compared with baculovirus-infected insect cells. (c) 1995 John Wiley & Sons, Inc.

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Section: Introductionsupporting

confidence: 79%

Influence of cell‐ and media‐derived factors on the integrity of a human monoclonal antibody after secretion into serum‐free cell culture supernatants

Ackermann

Jäger

Marx

1995

Biotech & Bioengineering

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“…Specifically, the sugar component of glycoproteins produced by chicken sternum cartilage chondrocytes was shown to be affected by changes in culture medium composition (Bernard et a/., 1984;Warren et al, 1982). Specifically, the sugar component of glycoproteins produced by chicken sternum cartilage chondrocytes was shown to be affected by changes in culture medium composition (Bernard et a/., 1984;Warren et al, 1982).…”

Section: Glycosylation Of Pm Proteinsmentioning

confidence: 99%

Peritrophic matrix proteins of Anopheles gambiae and Aedes aegypti

Moskalyk

Jacobs-Lorena

1996

Insect Molecular Biology

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Little is known about the composition and function of the mosquito peritrophic matrix (PM), a physical barrier that pathogens must traverse to complete their life cycles. Anopheles gambiae and Aedes aegypti PM proteins induced by blood or by a protein-free meal have been characterized by the use of 2-D gel electrophoresis and lectin-binding affinity assays. More than forty proteins have been identified in both species. Over half of the PM proteins of both mosquitoes migrate identically. Many PM proteins appear to be glycosylated, primarily by high mannose N-linked glycosyl groups.

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“…The polyanionic nature of the carbohydrate found on some cell surfaces probably results in marked cation and pH differences in this region relative to the surrounding medium (177). It has recently been proposed that the heterogeneity of carbohydrate structure found on proteins of this region might result in minor differences in protein function, leading to a broader range in the ionic strength and pH values optimal for protein function (36,37). As such, protein oligosaccharides might subserve a homeostatic process used by cells to maintain their viability in potentially changing milieus.…”

Section: Non-specific Functionsmentioning

confidence: 99%

Current ideas on the significance of protein glycosylation

West

1986

Mol Cell Biochem

106

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Carbohydrate has been removed from a number of glycoproteins without major effect on the structure or enzyme activity of the protein. Thus carbohydrate has been suggested to underly a non-primary function for proteins, such as in relatively non-specific interactions with other carbohydrates or macromolecules, stabilization of protein conformation, or protection from proteolysis. This non-specific concept is consistent with both the general similarity in carbohydrate structure on very diverse glycoproteins and the frequent structural microheterogeneity of carbohydrate chains at given sites. The concept is supported in a general sense by the viability of cells whose glycosylation processes have been globally disrupted by mutation or pharmacological inhibitors.In contrast to the above observations, other studies have revealed the existence of specific, selective receptors for discrete oligosaccharide structures on glycoproteins which seem to be important for compartmentalization of the glycoprotein, or the positioning of ceils on which the glycoprotein is concentrated. Sometimes multivalency in the carbohydrate-receptor interaction is crucial. There are additional possible roles for carbohydrate in the transduction of information upon binding to a receptor. The possibility of specific roles for carbohydrate is supported by the existence of numerous unique carbohydrate structures, many of which have been detected as glycoantigens by monoclonal antibodies, with unique distributions in developing and differentiated cells.This article attempts to summarize and rationalize the contradictory results. It appears that in general carbohydrate does in fact underlie only roles secondary to a protein's primary function. These secondary roles are simple non-specific ones of protection and stabilization, but often also satisfy the more sophisticated needs of spatial position control and compartmentalization in multicellular eukaryotic organisms. It is suggested that there are advantages, evolutionarily speaking, for the shared use of carbohydrate for non-specific roles and for specific roles primarily as luxury functions to be executed during the processes of cell differentiation and morphogenesis.

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Variation of the carbohydrates of glycoproteins of cells growing on different surfaces

Cited by 13 publications

References 24 publications

Influence of cell‐ and media‐derived factors on the integrity of a human monoclonal antibody after secretion into serum‐free cell culture supernatants

Influence of cell‐ and media‐derived factors on the integrity of a human monoclonal antibody after secretion into serum‐free cell culture supernatants

Peritrophic matrix proteins of Anopheles gambiae and Aedes aegypti

Current ideas on the significance of protein glycosylation

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