Perturbed Angular Correlation Study of a Haptenic Molecule

Abstract

The angular correlation of the 173-247 keV gamma-ray cascade after the electron-capture decay of 11"In is strongly perturbed when the I-p-nitrophenylethylenediaminetetraacetate chelate of lllIn3+ is added to a solution containing rabbit antibody to dinitrophenyl groups. The radioactive chelate can be displaced by the addition of dinitrophenyllysine or unlabeled chelate. The average association constant between the antibody and the labeled chelate has been estimated from perturbed angular correlation measurements; this value is compared to the results of equilibrium dialysis. These experiments provide good evidence that information concerning macromolecular behavior can be obtained from perturbed angular correlation experiments that use chemically specific labels.

Historical Perspective on Nanoparticles in Imaging from 1895 to 2000

“…Hence, the change of the environment affects (perturbs) the angular correlation and alters its rotational time. In the series of publications from 1972 to 1980, the group refined this technique, synthesized a variety of 111 In carrying liposomes, measured the liposomes' structural integrity in vivo, and finally demonstrated tissue specificity for targeting liposomes [27][28][29]. One of the outcomes of this study was the recognition and the rise of a variety of 111 In-labeled nanoparticles for SPecT imaging [30][31][32][33].…”

Bifunctional Chelates for Radio-Pharmaceutical Labeling

“…The tumor uptake and organ distribution we observed in tumor-bearing mice suggest a potential use of these radiopharmaceuticals in cancer localization in humans (6). A similar molecule has been used successfully to study antibody-hapten interactions (7), suggesting the application of bifunctional chelates to radioimmunoassay procedures. Other possible radiopharmaceuticals which could be labeled with m I n d i u m using this technique include antibodies such as anticarcinoembryonic antigen (anti-CEA) for cancer localization, trophic polypeptide hormones such as secretin for organ localization, and blood cells for distribution and turnover studies.…”

PAC research in biology

“…It was believed that PAC technique could gain usefulness as a labelling method, giving information concerning the localized behaviour and structure of a molecule near the labeled site [2].…”