Protein found in valley around Utah (6)
I believe the answer is:
gluten
'protein' is the definition.
(gluten is a kind of protein)
'valley around utah' is the wordplay.
'valley' becomes 'glen' (glen is a kind of valley).
'around' is an insertion indicator.
'utah' becomes 'ut' (I've seen this in other clues).
'glen' enclosing 'ut' is 'GLUTEN'.
'found in' acts as a link.
(Other definitions for gluten that I've seen before include "Gluey protein substance in flour" , "Sticky protein present in cereal grains" , "Gluey protein substance in wheat" , "Substance in cereal grain" , "Protein found in cereals" .)