O-Propargyl-Puromycin

O-Propargyl-Puromycin, an alkyne analog of puromycin, is a potent protein synthesis inhibitor. O-Propargyl-Puromycin is a click chemistry reagent, itcontains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups. In Vitro: O-propargyl-puromycin can be used to image and affinity-purify nascent proteins in cells and in animals. O-propargyl-puromycin inhibits protein synthesis, both in reticulocyte lysates and in cultured cells, displaying a potency two- to threefold lower than that of unmodified puromycin. O-propargyl-puromycin forms covalent conjugates with nascent polypeptide chains, which are rapidly turned over by the proteasome and can be visualized or captured by copper(I)-catalyzed azide-alkyne cycloaddition. ^[1]. In Vivo: Tissues from uninjected mice shows low nonspecific staining, whereas tissues from O-propargyl-puromycin-injected mice display specific patterns of O-propargyl-puromycin incorporation into nascent proteins. In the small intestine, translation is strongest in cells in the crypts and at the base of intestinal villi, consistent with the high proliferative and secretory activity of these cells. The stain is particularly strong in Paneth cells, which are located close to the base of the crypts and are filled with secretory vesicles. The intense O-propargyl-puromycin labeling of vesicles in Paneth cells suggests that prematurely terminated, O-propargyl-puromycin-conjugated secretory proteins are translocated into the endoplasmic reticulum (ER) lumen^[1].