These portions of Toxins A and B may be {HEAD ~ fusion proteins} with {TAIL ~ at least one non toxin protein sequence}, and may also be soluble and substantially endotoxin free 
with
These portions of Toxins A and B may be { HEAD ~ fusion proteins } with { TAIL ~ at least one non toxin protein sequence } , and may also be soluble and substantially endotoxin free
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH