N6-carboxy-L-lysine (2S)-2-amino-6-(carboxyamino)hexanoic acid 172.0847930908203125 172.17999267578125 2-amino-6-carbamic hexanoic acid 43.98983001708984375 44.009998321533203125 A protein modification that effectively converts an L-lysine residue to N6-carboxy-L-lysine. C 1 H 0 N 0 O 2 C 7 H 12 N 2 O 3 Carboxy Carboxylation K MOD:00123 MOD_RES N6-carboxylysine N6-carbamyllysine N6-carboxy-L-lysine N6-carboxylysine N6CbxLys PSI-MOD Unimod:299 lysine NZ-carboxylic acid natural uniprot.ptm:PTM-0191 modified L-lysine residue carboxylated residue