ELUTION OF HUMAN-IGG FROM AFFINITY COLUMNS CONTAINING IMMOBILIZED VARIANTS OF PROTEIN-A

Immobilised analogues of protein A have been used for affinity chromat ographic separation of human IgG. Truncation of the C-terminal region of an engineered IgG-binding domain based upon the B domain from prote in A, in combination with site-directed mutagenesis, has led to the ge neration of a number of proteins with a decreased affinity for IgG. Th e elution of human IgG from these proteins when immobilised onto a sol id support occurs over the pH range 3.2-5.0 with 0.5 M acetate buffer. These proteins may be effective alternatives to standard protein A co lumns when milder elution conditions are required.