Naturally occurring anti-native DNA antibodies in SLE binding Z-DNA.

A high degree of specificity of circulating anti-DNA antibody for double stranded DNA in the sera of SLE patients was found, as compared to single stranded polymer. The antibody recognized brominated DNA, a polymer that appears to attain Z-conformation as indicated on the basis of UV absorption characteristics. The existence in native DNA of regions undergoing B----Z transition has been detected.