Characterization of Histogranin Receptors in Human Peripheral Blood Lymphocytes
Brain and Mind Institute
Histogranin (HN), a peptide recently isolated from bovine adrenal medulla, is also present in the spleen. In present studies, specific high affinity binding sites for HN were characterized on membrane preparations of human lymphocytes by radioligand binding. [125I]-[Ser1]HN binding was found to be dependent on time and protein concentration and to be sensitive to trypsin treatment. The binding displayed high affinity (Kd = 1.1 ± 0.3 nM) and saturability (Bmax = 40.2 ± 5.0 fmol/mg protein), and it was reversed upon addition of unlabelled [Ser1]HN and closely related peptides. The relative potency of various fragments in displacing [125I][Ser1]HN binding indicated that the active core of the molecule resides inside the C-terminal fragment, HN-(6-15). Interestingly, depressed patients displayed a marked decrease in the binding activity (from 15.4 to 8.55 fmol/mg protein at 0.5 nM of [125I][Ser1]HN). The presence of high affinity HN binding sites on lymphocytes provides evidence for a modulatory role for HN in the regulation of lymphocyte functions.
Biochemical and Biophysical Research Communications
Ravindran, A. V.
(1993). Characterization of Histogranin Receptors in Human Peripheral Blood Lymphocytes. Biochemical and Biophysical Research Communications, 194(3), 1323-1329.
Available at: https://ecommons.aku.edu/bmi/234