Duck (Anas platyrhynchos) has three types of serum Immunoglobulins: one is IgM with a molecular weight (MW) of ~900 kDa and the other two are low MW immunoglobulins formerly referred to as IgG, now known as IgY. Both isoforms of IgY exist in the duck: one is full-length and the other is truncated. The full-length IgY (of 7.8S sedimentation coefficient) is equivalent in size to the IgY of the chicken and the truncated IgY (5.7S) appears to be the equivalent of an F(ab')2 fragment of the 7.8S molecule.
Immunoglobulins of Duck |
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Sedimentation coefficient |
Molecular Weight of |
||
Whole molecules (kDa) |
Heavy chains (kDa) |
Light chains (kDa) |
|
IgM |
800-900 |
86 |
23-25 |
IgY |
178-200 |
62-67 |
22-25 |
IgY( ΔFc) |
118-130 |
35-42 |
22-25 |
The IgY molecule consists of two heavy (H) and two light (L) chains. The H chain of the full-length IgY possesses one variable (VH) and four constant (Cu1, Cu2, Cu3, and Cu4) region domains. The truncated IgY, lacking the two terminal domains of the constant region, Cu3, and Cu4, of the H chain, resembles a structural equivalent F(ab')2 fragment of IgY, thus named as IgY(ΔFc) or IgY(-Fc) for the intact molecule and u(ΔFc) for its H chain.
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