SLE autoantibodies recognize spermine induced Z-conformation of native calf thymus DNA

The binding specificity of naturally occurring anti-DNA antibodies with spermine modified DNA was analyzed by direct binding and competition ELISA. The binding was visualised by band shift assay. The SLE anti-DNA antibodies appreciably recognized the spermine induced Z-conformation of native DNA. The degree of binding of these antibodies to the Z-conformer was almost similar to their binding with native DNA. The spermine-DNA complex was found to be thermodynamically more stable than native DNA.