{HEAD ~ The invention} also provides an isolated or purified preparation of {TAIL ~ an MRT} polypeptide 
{ HEAD ~ The invention } also provides an isolated or purified preparation of { TAIL ~ an MRT } polypeptide
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH