6x(13)C,2x(15)N labeled L-lysine (12)C -6 (13)C 6 (14)N -2 (15)N 2 (13)C 6 H 12 (15)N 2 O 1 136.109161376953125 136.1100006103515625 13C(6) 15N(2) Silac label 8.0100002288818359375 8.0141992568969726562 A protein modification that effectively converts an L-lysine residue to 6x(13)C,2x(15)N labeled L-lysine. K Label:13C(6)15N(2) MOD:00582 PSI-MOD Unimod:259 artifact lys-13C615N2 (13)C labeled residue (15)N labeled residue modified L-lysine residue