| abstract |
A polypeptide comprising a constant light chain kappa domain of a human antibody (CLk) comprising residues K and H at positions corresponding to positions 80 and 81 of SEQ ID NO: 6 when said constant light chain kappa domain of Human antibody is aligned with the sequence of SEQ ID NO: 6, and characterized in that the constant light chain kappa domain of the human antibody further comprises a residue selected from the group consisting of A, G, I, V, L, R, S , T, Q, P, N, M, H, W in a position corresponding to position 77 of SEQ ID NO: 6. |