{HEAD ~ A preferred protein} is {TAIL ~ an enzyme} such as thermolysin, elastase, asparaginase, lysozyme, lipase or urease 
is
{ HEAD ~ A preferred protein } is { TAIL ~ an enzyme } such as thermolysin , elastase , asparaginase , lysozyme , lipase or urease
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH