Gottlieb P, Hazum E, Tzehoval E, Feldman M, Segal S, Fridkin M
Biochem Biophys Res Commun. 1984 Feb 29;119(1):203-11. doi: 10.1016/0006-291x(84)91639-5.
A fluorescent analog of the phagocytosis stimulating peptide tuftsin was prepared by coupling tetramethyl rhodamine isothiocyanate to a C-terminal elongated derivative of tuftsin. This analog, Thr-Lys-Pro-Arg-Gly-Lys(N epsilon-tetramethyl rhodamine)-OH, was used to visualize tuftsin receptors on mice macrophage cells by fluorescent image intensification. Fluorescent labelling was carried out at 37 degrees C, using a concentration of 200 nM and 2 microM of the fluorescent tuftsin derivative. The formation of peptide-receptor clusters and their subsequent internalization, as discerned by image intensification, were rapid processes, 5 min and 5-30 min, respectively. Preincubation of macrophages with tuftsin for various time intervals, followed by quantification of the tuftsin receptor using radiolabelled tuftsin, suggest that tuftsin receptors are initially increased in amount (5-7 min) and subsequently reduced (after 10-15 min) as judged by sites available for tritiated tuftsin. The binding studies are rather complementary to the fluorescence observations and support the assumption that the tuftsin receptor on the membrane of the mice macrophage cell is rapidly mobilized.
通过将异硫氰酸四甲基罗丹明与促吞噬肽tuftsin的C端延长衍生物偶联，制备了一种tuftsin的荧光类似物。这种类似物，苏氨酸-赖氨酸-脯氨酸-精氨酸-甘氨酸-赖氨酸（Nε-四甲基罗丹明）-OH，被用于通过荧光图像增强技术观察小鼠巨噬细胞上的tuftsin受体。荧光标记在37摄氏度下进行，使用200 nM和2 μM的荧光tuftsin衍生物浓度。通过图像增强技术观察到，肽-受体簇的形成及其随后的内化分别是快速过程，分别为5分钟和5 - 30分钟。用tuftsin对巨噬细胞进行不同时间间隔的预孵育，然后使用放射性标记的tuftsin对tuftsin受体进行定量，结果表明，根据可与氚化tuftsin结合的位点判断，tuftsin受体的数量最初会增加（5 - 7分钟），随后减少（10 - 15分钟后）。结合研究与荧光观察结果相当互补，并支持小鼠巨噬细胞膜上的tuftsin受体迅速移动的假设。
