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