. "The process of covalently altering one or more amino acids in a protein after the protein has been completely translated and released from the ribosome." . . "PTM" . "post-translational protein modification" . "post-translational amino acid modification" . "post-translational modification" . "posttranslational amino acid modification" . "posttranslational modification" . "posttranslational protein modification" . . . . . .