Source:http://linkedlifedata.com/resource/umls/id/C1521754
GO: The addition of an acetyl group to a protein amino acid. An acetyl group is CH3CO-, derived from acetic [ethanoic] acid. [GOC:ai],NCI: The covalent chemical or post-translational biochemical addition of an acetyl group(s) to a peptide or protein. (NCI)