Protein A G Binding Affinity
Relative binding strengths of antibodies from various species to protein G and protein A as measured in a competitive ELISA test. The amount of IgG required to give a 50% inhibition of binding of rabbit IgG conjugated with alkaline phosphatase was determined.
| Species | Subclass | Protein G binding | Protein A binding |
|---|---|---|---|
| Human | IgA IgD IgE IgG1 IgG2 IgG3 IgG4 IgM* |
– – – ++++ ++++ ++++ ++++ – |
variable – – ++++ ++++ – ++++ variable |
| Avian egg yolk | IgY† | – | – |
| Cow | ++++ | ++ | |
| Dog | + | ++ | |
| Goat | ++ | – | |
| Guinea pig | IgG1 | ++ | ++++ |
| Hamster | ++ | + | |
| Horse | ++++ | ++ | |
| Koala | + | – | |
| Llama | + | – | |
| Monkey (rhesus) | ++++ | ++++ | |
| Mouse | IgG1 IgG2a IgG2 IgG3 IgM* |
++++ ++++ +++ +++ – |
+ ++++ +++ ++ variable |
| Pig | +++ | +++ | |
| Rabbit | +++ | ++++ | |
| Rat | IgG1 IgG2a IgG2 IgG3 |
+ ++++ ++ ++ |
– – – + |
| Sheep | ++ | +/– |
- Purified using HiTrap IgM Purification HP columns.
† Purified using HiTrap IgY Purification HP columns.
++++ = strong binding.
++ = medium binding.
— = weak or no binding.