The Application of Perturbed Directional Correlation of Gamma Rays to the Study of Protein-Metal Interactions

Application to Chemistry of Electric Quadrupole Perturbation of γ-γ Angular Correlations

“…Determination of such important things as rotational correlation times, conformation changes of macromolecules, binding constants, metal-protein interactions, chemical structure of metalion binding sites on proteins are amenable to the PAC technique. Excellent reviews in the field [19,20] have helped to render PAC less esoteric to macromolecular chemists and to biochemists, therefore this topic does not need to be further discussed here. PAC experiments performed on radioactive nuclides in solutions are usually aimed to deliver the perturbationfree A k parameters, since the very short correlation times ensure that G k (r) -1.…”

“…These developments have immediate implications to biomolecules. The applications of PAC methods to the study of metal-protein interactions have been exhaustively reviewed by GRAF et al [19]. Application to the investigation of molecular motions in liquids has been considered by BOYER and VUILLET [20].…”

“…All the relevant parameters for the three selected cascades are given in Table 1. Data on other nuclides can be found in [8] and [19]. the latter requires fast-slow coincidence circuits which are commonly used in nuclear physics and are described in several textbooks [21 ].…”

Gamma-gamma directional correlation study of model membranes

“…The theory of PDC has been reviewed extensively (Frauenfelder and Steffen, 1966), and applications to biophysical systems have been previously reported (Liepert et al, 1968;Meares et al, 1969;Graf et al, 1974;Richer et al, 1974). If a radioactive nuclide decays by a gammagamma cascade, we may define the directional correlation function, W(O), as the relative probability that the second gamma photon is emitted at some angle 0 with respect to the direction of emission of the first photon.…”