Part One: Investigation of the Immunogenicity of a Spin Label Probe. Part Two: An Electron Paramagnetic Resonance Study of Dinitrophenyl-Binding Myelomas and Hybridomas Using Spin Labelled Probes

200 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.In Part One, the spin label 2,2,5,5-tetramethylpyrrilidin-3-carboxyl-1-oxyl (tmcpo) was investigated for its immunogenicity at attempting covalent attachment of the probe to a carrier molecule. Detectable immune responses to these immunogens in New Zealand adult rabbits could not be observed with either capillary precipitin tests, immunoelectrophoresis, or epr studies. Fluorescamine was used to quantitate the substitution of the spin probe on BSA, and results indicated the spin probe was leaching from the carrier. Epr studies confirmed the leaching phenomenum. Formation of an ammonium carboxylate ion pair was proposed rather than the anticipated amide bond.Two other spin label adducts were studied as possible immunogens. A tmcpo-imidazole adduct did not provide adequate epitope density for potent immunogenicity. A 2,2,5,5-tetramethyl-3-aminopyrrilidin-1-oxyl (tmapo)-maleimide did result in high substitution with the probe sufficiently immobilized.In Part Two, the Dnp binding myeloma MOPC 315 was titrated with Dnp-tmapo and monitored with epr. The equilibrium between the hapten and MOPC 315 included active site associated hapten, a secondary hapten association, and free aqueous hapten. Based on inhibition studies with Dnp-glycine, the secondary associated hapten was localized in the binding pocket of antibody.Anti-Dnp hybridomas were studied with the Dnp-tmapo spin label adduct. The lateral dimensions for protein HPD-1 were estimated as 0.65 nm or greater on either side of the spin label, while lateral dimensions for the active site of 29-22 were 0.60 nm. These two Dnp induced proteins possessed a more open active site than has been established for MOPC 315. The trend in active site regidity was MOPC 315 > 29-22 > HPD-1. Affinity toward Dnp-glycine, determined by fluorescence quenching, followed the trend HPD-1 > 29-22 > MOPC 315. The active site providing the most rigid environment for the hapten expressed the lowest affinity toward Dnp-glycine. Removal of bound hapten was most difficult in the hybridomas, yet facile for MOPC 315, even though affinities were only a factor of four different. This suggests a difference in the nature of the induced hybridoma active sites from the myeloma.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD