Effect of tunicamycin, an inhibitor of protein glycosylation, on the biological properties of acetylcholine receptor in cultured muscle cells.

摘要: We have studied the effect of tunicamycin (TM), an antibiotic which inhibits glycosylation nascent proteins, on properties acetylcholine receptor (AChR) at surface embryonic chick skeletal muscle cells. The use two separate assays, specific binding 125I-alpha-bungarotoxin and carbamylcholine-activated 22Na+ uptake, has allowed us to monitor effects impaired metabolic functional AChR. A significant decrease in amounts AChR elaborated presence TM is detected by both measurements. This been found reflect enhanced proteolytic degradation underglycosylated AChR, expressed cell TM, retains capability mediating agonist-activated ionic permeability changes, but displays quantitatively altered interactions with ligands. conclude that carbohydrate moiety may play a role determining folding newly synthesized polypeptides form conformation compatible ligand characteristic glycosylated