Metalloprotein

**Semantic type:** Amino Acid, Peptide, or Protein

**Definition:** Proteins that include a metal ion as part of their structure or they contain a metal cofactor. The metal ion can be an isolated ion or coordinated with a nonprotein organic compound, such as the porphyrin moiety found in hemoproteins. Additionally, the metal can be co-coordinated with both a side chain of the protein and an inorganic nonmetallic ion.