Protein that inhibits both nicotinic (nAChR) and muscarinic (mAChR) acetylcholine receptors. The nAChR is a postsynaptic membrane protein that, after binding acetylcholine, responds by an extensive change in conformation, which leads to opening of an ion-conducting channel across the plasma membrane. The mAChR is a membrane protein that acts through G proteins and mediates various cellular responses, including inhibition of adenylate cyclase, breakdown of phosphoinositides and modulation of potassium channels through the action of G proteins.