Neal tossed hobo in water-soluble protein (7)
I believe the answer is:
albumen
'water-soluble protein' is the definition.
'albumen' can be an answer for 'protein' (albumen is a kind of protein). I'm not certain of the 'water-soluble' bit.
'neal tossed hobo in' is the wordplay.
'tossed' is an anagram indicator.
'hobo' becomes 'bum' (synonyms).
'in' means one lot of letters goes inside another.
'neal' with letters rearranged gives 'alen'.
'alen' enclosing 'bum' is 'ALBUMEN'.
Can you help me to learn more?
(Other definitions for albumen that I've seen before include "White poacher" , "Egg-white" , "Egg's white" , "The white part of an egg" .)