Antibodies specific to a deoxyribodinucleotide sequence

Purification of antibodies specific to a dinucleotide using the hapten bound to DEAE cellulose as an affinity column

The dinucleotide dpTpA held electrostatically on DEAE cellulose was used as an affinity column for the purification of dpTpA specific antibodies. Chromatography of the gamma-globulin fraction from dpTpA specific antisera on this column resulted in the retention of dpTpA specific antibodies which were later eluted along with the bound dpTpA using 1M NaCl. Dextran coated charcoal was the method of choice for the dissociation and removal of dpTpA bound to the antibodies. This method may extend itself to the purification of antibodies specific for other oligonucleotides.

Antibodies to DNA

Antibodies that recognize specific conformational variations of DNA structure provide sensitive reagents for testing the extent to which such conformational heterogeneity occurs in nature. A most dramatic recent example has been the development and application of antibodies to left-handed Z-DNA. They provided the first identification of Z-DNA in fixed nuclei and chromosomes, and of DNA sequences that form Z-DNA under the influence of supercoiling. Antibodies have also been induced by chemically modified DNA and by synthetic polydeoxyribonucleotides that differ from the average B-DNA structure. These antibodies recognize only the features that differ from native DNA. In most experiments, native DNA itself is not immunogenic. Antibodies that do react with native DNA occur in sera of patients with autoimmune disease, but even monoclonal anti-DNA autoantibodies usually react with other polynucleotides as well. Anti-DNA antibodies, especially those of monoclonal origin, provide a model for the study of protein-nucleic acid recognition.

Base specific binding of deoxyguanylate and deoxycytidylate antibodies to double stranded DNA

Antibodies raised in rabbits against deoxyguanylate and deoxycytidylate bind to 3H-lambda double stranded DNA and the binding is base specific. The concentrations of antibody populations that bind to double stranded DNA are much less than those binding to denatured DNA. Due to their low concentrations, these antibodies were not detected in earlier studies. These antibodies are expected to be useful to probe the conformational flexibilities of double stranded DNAs.

Monoclonal antibodies showing sequence specificity in their interaction with single-stranded DNAs

Six hybridoma cell lines which secrete monoclonal antibodies binding to nucleic acids were produced from autoimmune NZB/NZW mice. Four of the antibodies were IgG's and the other two were IgM's. Using a solid phase radioimmunoassay (SPRIA) the binding of the antibodies to over thirty different nucleic acids was estimated. All the antibodies were extremely specific. There was no detectable interaction with various RNAs, and single-stranded DNAs bound more antibodies than duplex or multi-stranded DNAs. In every case the antibodies also showed considerable sequence preferences. For example one monoclonal antibody bound to d(TTC)n but not to d(TCC)n while another interacted strongly with D(TG)n and d(CA)n but not with d(TC)n, d(GA)n or homopolymers. In other cases the patterns of sequence specificity were extremely difficult to interpret although it seems clear that monoclonal antibodies have the potential to distinguish between any two nucleic acids however similar.

Antibodies elicited by defined oligodeoxyribonucleotide sequences

Antibodies to the oligodeoxyribonucleotides d(pT)3, d(pT)4, d(pT)6 and d(pA-A-T-T) were elicited in rabbits by immunization with electrostatic complexes of the respective haptens with methylated bovine serum albumin (MBSA). The antisera were assayed by complement fixation using denatured DNA's of various sources as antigens. The specificities of the antibodies were determined by estimating the inhibition of the complement fixation reaction by defined oligodeoxyribonucleotides. The antibodies were shown to be specific for the sequence of the oligode-oxyribonucleotides or parts of it.

Formation and characterization of antibody against 2'-(5"-phosphoribosyl)-5' AMP, the monomer form of poly(adenosine diphosphate ribose)

Specific antibody against 2'-(5"-phosphoribosyl)-5'AMP (PR-AMP), a monomer of poly(adenosine diphosphate ribose) (poly(ADP-Rib)), was produced by immunizing a rabbit with PR-AMP coupled to bovine serum albumin (BSA). Antibody against PR-AMP was purified 53-fold from serum by (NH4) 2SO4 precipitation, and BSA-Sepharose 4B, DEAE-cellulose and (PR-AMP)-BSA-Sepharose 4B column chromatographies. Inhibition experiments show that the adenine ring, 5'-phosphate residue and ribose-ribose bond of PR-AMP were essential for the antigenic determinant of PR-AMP. Anti PR-AMP antibody bound, not only with PR-AMP, but also with poly(ADP-Rib) of various chain lengths, while anti poly(ADP-Rib) antibody bound with poly(ADP-Rib) but not with PR-AMP.