preferred_name: L-arginyl-[protein] + methylglyoxal => N(omega)-(1-hydroxy-2-oxopropyl)-L-arginyl-[protein]
preferred_name_lc: l-arginyl-[protein] + methylglyoxal => n(omega)-(1-hydroxy-2-oxopropyl)-l-arginyl-[protein]
label: L-arginyl-[protein] + methylglyoxal => N(omega)-(1-hydroxy-2-oxopropyl)-L-arginyl-[protein]
label_lc: l-arginyl-[protein] + methylglyoxal => n(omega)-(1-hydroxy-2-oxopropyl)-l-arginyl-[protein]