modified L-proline residue 5x(13)C labeled L-proline 102.0695343017578125 102.0800018310546875 5.0167741775512695312 5.0199999809265136719 Label:13C(5) artifact 13C(5) Silac label A protein modification that effectively converts an L-proline residue to 5x(13)C labeled L-proline. MOD:01297 P H 7 (13)C 5 N 1 O 1 In PubMed:12716131, fully (13)C labeled proline apparently resulted from the catabolic conversion of (13)C labeled L-arginine during SILAC. PSI-MOD none (12)C -5 (13)C 5 5x(13)C-labeled residue