Further processing of the mature form apparently occurs in some instances to yield {HEAD ~ biologically active fragments} of {TAIL ~ the protein} 
Further processing of the mature form apparently occurs in some instances to yield { HEAD ~ biologically active fragments } of { TAIL ~ the protein }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL