In their native state they are {HEAD ~ an antagonist} of {TAIL ~ the alpha nicotinic acetylcholine receptor} 
of
In their native state they are { HEAD ~ an antagonist } of { TAIL ~ the alpha nicotinic acetylcholine receptor }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL