Heparin inhibition and polyamine stimulation of a glycogen synthase kinase (PC0.7) from rabbit skeletal muscle

Molecular motion of 1,6-diphenyl-1,3,5-hexatriene embedded in intact guinea pig alveolar macrophage membranes was investigated by using techniques of nanosecond timeresolved fluorescence anisotropy measurements in the temperature range of 0–50 °C, and as a function of benzyl alcohol concentration. It was shown that molecular arrangement and microheterogeneity of the hydrocarbon region surrounding 1,6-diphenyl-1,3,5-hexatriene molecules are dependent on the temperature and benzyl alcohol concentration. The lipid orientation order parameter, S_v, showed a discontinuity in the temperature range 12–40 °C, which may indicate a phase transition. N-Formylmethionylphenylalanine-stimulated production of O₂^? from macrophages increased with temperature parallel with changes in S_v. Benzyl alcohol decreases the magnitude of the lipid order parameter at all temperatures studied. In the same concentration range of benzyl alcohol, stimulated O₂^? production by macrophages was inhibited. These data show the complex relationship between lipid integrity in macrophage membranes and a physiological function of these cells. In addition, the results indicate that benzyl alcohol influences the integrity of both the protein and lipid hydrophobic regions of the membrane.