PROPERTIES OF TRNA-SPECIFIC ANTIBODIES FROM NZB-NZW MICE

Abstract

Antibodies that bind tRNA are produced spontaneously in New Zealand Black/New Zealand White (NZB/NZW) F1 hybrid female mice. An assay for the detection of these antibodies was developed by using gel filtration and radioactive tRNA. This assay was superior to the (NH4)2SO4 precipitation assay because of the nature of the interaction between the protein and tRNA. The antibodies bound native tRNA preferentially to tRNA denatured by cross-linking with formaldehyde. This conformational specificity was confirmed in competition experiments. The antibodies to native tRNA had an average association constant of 5 .times. 107 l/mol at 4.degree. C and could bind to > 1 site per tRNA molecule. Experiments with immunoglobulin [Ig] class-specific anti-mouse antisera, in solution and by radioimmunoelectrophoresis, showed that the antibodies were heterogeneous, but were predominantly of the IgG class. These antibodies may be useful for detection, localization and conformational analysis of tRNA in solution as well as for understanding the pathogenesis of the lupus-like syndrome in these mice.