Stimulation of the Na/K pump in LK sheep erythrocytes by immunoglobulin fragments.

Alloimmune antiserum against the L antigen of red cells from sheep of the LK phenotype is known to stimulate by several fold active Na/K transport in LK cells. We have shown that monomeric fragments, Fab1, of anti-L, as well as dimeric fragments, F(ab1)2, stimulate transport to the same extent as intact anti-L Ig. Special care was taken to obtain pure fragments. Two earlier reports on the effect of immunoglobulin fragments were contradictory.