The building blocks of English

Affixes

prote(o)-

Protein.

English protein plus ‑o‑.

A protease is an enzyme which breaks down proteins and peptides, a process called proteolysis (Greek lusis, loosening); a proteoglycan is a compound consisting of a protein bonded to mucopolysaccharide groups, present especially in connective tissue; a proteolipid is a type of lipoprotein occurring mainly in the brain.