It was merely the public manifestation of a shift that began further up the chain.
Due to the shift of the side chain of Tyr147, a hydrophobic interaction with this residue is lost in the 3-epimer structure.
The gel shows a ~4 kDa shift of the heavy chain of IgG and a corresponding lack of LCA lectin signal when incubated with EndoS2, EndoS or PNGase F, but not with EndoS2(E186L) or PBS.
The fragments were separated on a nonreducing gel and subsequent Lens culinaris agglutinin (LCA) lectin blotting (recognizing mannose residues) revealed activity of EndoS and EndoS2 only on the Fc fragment of cetuximab, seen as a shift of the heavy chain and loss of LCA signal, and no size shift and unchanged signal in LCA blotting of the F ab′ 2 fragment.
In a subsequent functional assay incubating IgG with the bacterial supernatant, loss of the N-linked glycan on IgG was visualized as a 4 kDa shift of the heavy chain on the electrophoresis gel and corresponding lack of signal in the LCA lectin blot.
Finally, the silicate chains were staggered with a shift of b/2, with the displacement of the chains resulting in a reduction in symmetry to space group P21/ c; a = 11.35, b = 7.3, c = 28.8 Å, β = 95.5°; T∞_14sc.
Remarkably, these properties arise simply out of a one-atom position shift of the peptide side chain from the alpha-carbon to the amide nitrogen along the peptide backbone.
Incubation of IgM with wt Cc5 bacteria determined a dramatic reduction of SNA staining and a size shift of the IgM heavy chain indicating deglycosylation while incubation with PUL5 mutant bacteria did not affect the glycosylation state of IgM showing that IgM deglycosylation by Cc5 is only PUL5 dependent.
Each vertical line in each TOCSY spectrum corresponds to the spin system of one amino acid, with the amide proton resonance on the x-axis and the chemical shifts of the side chain proton resonances on the y-axis.
In a video released by the company today, Deborah Wahl, chief marketing officer for McDonald's USA, says the campaign is part of "a brand transformation" that shifts the chain's focus "from billions served to billions heard".
