The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.

Synonyms: Substitution, Amino Acid, Amino Acid Substitutions, Substitutions, Amino Acid, Amino Acid Substitution