Naturally occurring glycan forms of human immunoglobulins G1 and G2

Flynn, Gregory C.; Chen, Xiaoyu; Liu, Y. Diana; Shah, Bhavana; Zhang, Zhongqi

doi:10.1016/j.molimm.2010.04.006

Cited by 119 publications

(117 citation statements)

References 22 publications

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“…51,52,54 A very low level (0.1%) of aglycosylation has been found in human IgG. 50 Clinical experience with aglycosylated antibodies did not demonstrate increased risk. 58 …”

Section: Aglycosylated Antibodiesmentioning

confidence: 99%

“…Human IgG antibodies share the same major and minor glycoforms with recombinant mAbs. 49,50 The majority of the oligosaccharides of human and recombinant IgGs include core-fucose. In most cases, the levels of terminal galactose and bisecting residue are higher in human IgG compared with recombinant IgG molecules.…”

Section: Oligosaccharidesmentioning

confidence: 99%

“…37 High mannose has been observed in endogenous human IgG at a very low level. 50 Immunogenic Oligosaccharides a-1,3 gal is not present in endogenous human IgG antibodies due to the absence of the gene for the synthesizing enzyme, a-1,3-galactosyltransferase. 49,63,64 Therefore, a1,3 gal is foreign to the human immune system.…”

Section: High Mannosementioning

confidence: 99%

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In vitro and in vivo modifications of recombinant and human IgG antibodies

Liu

Ponniah

Zhang

et al. 2014

mAbs

150

119

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“…51,52,54 A very low level (0.1%) of aglycosylation has been found in human IgG. 50 Clinical experience with aglycosylated antibodies did not demonstrate increased risk. 58 …”

Section: Aglycosylated Antibodiesmentioning

confidence: 99%

Section: Oligosaccharidesmentioning

confidence: 99%

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In vitro and in vivo modifications of recombinant and human IgG antibodies

Liu

Ponniah

Zhang

et al. 2014

mAbs

150

119

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“…Isolation of Endogenous Antibodies-Endogenous IgGs were isolated from healthy human donors by protein A affinity chromatography as previously described (14). Briefly, repeated injections of serum of 60 l, isolated as described above, were passed over a Poros A/20 protein A column (Applied Biosystems, part number: 1-5022-24) equilibrated in 20 mM Tris, 150 mM NaCl, pH 7.…”

Section: Lc/ms/ms Analysis With Ltq Ms-mentioning

confidence: 99%

N-terminal Glutamate to Pyroglutamate Conversion in Vivo for Human IgG2 Antibodies

Liu

Goetze

Bass

et al. 2011

Journal of Biological Chemistry

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162

124

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Therapeutic proteins contain a large number of post-translational modifications, some of which could potentially impact their safety or efficacy. In one of these changes, pyroglutamate can form on the N terminus of the polypeptide chain. Both glutamine and glutamate at the N termini of recombinant monoclonal antibodies can cyclize spontaneously to pyroglutamate (pE) in vitro. Glutamate conversion to pyroglutamate occurs more slowly than from glutamine but has been observed under near physiological conditions. Here we investigated to what extent human IgG2 N-terminal glutamate converts to pE in vivo. Pyroglutamate levels increased over time after injection into humans, with the rate of formation differing between polypeptide chains. These changes were replicated for the same antibodies in vitro under physiological pH and temperature conditions, indicating that the changes observed in vivo were due to chemical conversion not differential clearance. Differences in the conversion rates between the light chain and heavy chain on an antibody were eliminated by denaturing the protein, revealing that structural elements affect pE formation rates. By enzymatically releasing pE from endogenous antibodies isolated from human serum, we could estimate the naturally occurring levels of this post-translational modification. Together, these techniques and results can be used to predict the exposure of pE for therapeutic antibodies and to guide criticality assessments for this attribute.

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“…Copurification of endogenous IgGs of the same subclass as the therapeutic mAb may therefore lead to errors in interpretation in situations where attribute levels differ significantly between therapeutic IgG and endogenous IgGs. To illustrate, therapeutic mAbs produced in CHO cell culture may contain both glycan structures not found in measurable levels on endogenous human IgG antibodies, 32 as well as specific glycoforms in proportions quite different from those found on endogeneous IgG of the same subclass. 32 A change in the level of such an attribute over time in vivo may be attributed to altered rates of clearance, but could also arise artifactually from dilution with the identical peptide from endogenous antibodies of the same subclass, due to decreasing sample purity.…”

Section: Purity Considerations and Potential Artifactsmentioning

confidence: 99%